[cctalk] Re: Dysan Alignment and Performance Testers
The Tek 465/475 scopes are the best analog scopes ever made, IMHO. And with the best analog triger I think you might be able to get the cat eye to work on a sampling scope by adjusting the persistence. At least that's what I would do with my PicoScope. On 10/2/2024 8:28 PM, Jonathan Chapman via cctalk wrote: Cats eye don't tend to work well with digital sampling scopes unless they have a large sweep buffer and can keep the high speed sample rates at a slow sweep speed of a single full revolution. I don't know of any cheap ones that don't change the sample rate with the sweep rate. Even our older Tek DSO does poorly with the analog alignment patterns...not just the "cat's eye" radial alignment pattern, but also the azimuth bars. Index burst is "good enough" on it and sometimes the ability to introduce large, precise trigger delays makes it the more suitable tool (like for some alignments where we don't have the correct, factory-specified AAD and have to calculate the index offset). The old Tek 465 does excellent though :P Thanks, Jonathan
[cctalk] Re: Dysan Alignment and Performance Testers
Floppy Alignment disks have analog signals of varying intensity recorded on them. A flux detector like the greaseweazle is a binary (presence/absence) device. It also has off track signals on it. I don't think there is any way to create them with anything but a specially modified drive connected to a special controller. On 10/2/2024 7:36 PM, Chuck Guzis via cctalk wrote: On 10/2/24 16:04, Ali via cctalk wrote: I assume it's not easy to copy alignment disks, but I guess I will find out. It's actually not possible to copy them. Not for any "copy protection" reasons, but just the very nature of the analog signal laid down on the disk. No "regular" disk drive can recreate the signal. Chuck had actually talked about how to make one on a VCF post a while back: https://forum.vcfed.org/index.php?threads/greaseweazle-v4-reading-m1-5-25-fl oppies-on-a-sa400a-drive.1242918/post-1380519. Didn't sound like it was going to be as easy as copying a disk... ;) No, not easy, but possible, given skill, equipment and patience.
[cctalk] Re: Dysan Alignment and Performance Testers
And or course if you wanted to align the Processor Technology Helios-II drives you were in for an afternoon of "fun". Persci drives with voice coil head steppers and one spindle motor for both drives. On 10/2/2024 8:53 PM, Fred Cisin via cctalk wrote: Some of the old-timers might remember a guy who was on this list a long time ago, who claimed that the "copy-protectin defeating" program that he used could copy ANYTHING, even alignment disks! On Wed, 2 Oct 2024, Glen Slick via cctalk wrote: Thanks for the bad flashbacks from 14 years ago. Sorry.
[cctalk] PiDPI-8/I revision question - version 2 - reposted
Oscar, I am building a second PiDP-8/I kit that I bought, unassembled, from a gentleman in the UK, a couple of years ago. The circuit board in the kit is labeled Rev 2.2 2016-02-16. You call this the 2016-18 version. This version did not come with the LED spacers or the LED cover bracket and the switches have a much larger front metal piece and have mounting holes in them. Would it make sense for me to buy the LED spacers, LED bracket and possibly the updated PC board for this kit before putting it together? If so how much should I send you? What else would I need to upgrade to go with the newest PCB? If I don't upgrade the PCB, Are there any cuts and jumpers that I should do before assembling the circuit board? What is the correct deposit switch inversion for this board? Will I have any problems running any of the Raspberry Pi versions on this kit (Zero through 5)? I will be benchmarking the new build of the PiDP SIMH software on a bunch of different Pi's so compatibility is an issue. Thank you, Mike P.S. Is there any chance you will be at VCF Midwest this year?
[cctalk] PdPI-8/I revision question - version 2 - reposted
Oscar, I am building a second PiDP-8/I kit that I bought, unassembled, from a gentleman in the UK, a couple of years ago. The circuit board in the kit is labeled Rev 2.2 2016-02-16. You call this the 2016-18 version. This version did not come with the LED spacers or the LED cover bracket and the switches have a much larger front metal piece and have mounting holes in them. Would it make sense for me to buy the LED spacers, LED bracket and possibly the updated PC board for this kit before putting it together? If so how much should I send you? What else would I need to upgrade to go with the newest PCB? If I don't upgrade the PCB, Are there any cuts and jumpers that I should do before assembling the circuit board? What is the correct deposit switch inversion for this board? Will I have any problems running any of the Raspberry Pi versions on this kit (Zero through 5)? I will be benchmarking the new build of the PiDP SIMH software on a bunch of different Pi's so compatibility is an issue. Thank you, Mike P.S. Is there any chance you will be at VCF Midwest this year?
[cctalk] Re: Antonio's call for donations (was LCM auction)
We can't have any mud bloods amongst our ranks, now can we. 😂 On 8/30/2024 2:33 PM, Bill Gunshannon via cctalk wrote: On 8/30/2024 1:45 PM, Norman Jaffe via cctalk wrote: You do realize that 'Pureblood' is a phrase most definitely associated with the Aryan Nations and other neo-Nazi, white supremacist hate groups? And Wizards and Witches. Don't forget them. bill
[cctalk] Re: LCM auction
And then there's the story in the bible about Jesus throwing the people selling indulgences (and other things) out of the temple?😮 That kind of thing has been going on for thousands of years. It predates Catholicism but became a part of the Catholic Church in the 11th and 12 centuries. This is not intended to start a theological discussion in any way shape or form. I was just mentioning that buying your salvation has been a part of mankind for a long time. On 8/29/2024 7:01 PM, Fred Cisin via cctalk wrote: Hasn't he promised to give his money away... Yes He is a follower of Carnegie. Ruthlessly make an enormous amount of money, and then "buy your way into heaven" by doing good deeds with a large part of the money. Look at the Carnegie libraries. On Thu, 29 Aug 2024, Paul Koning wrote: In an earlier century, those schemes were called "indulgences" and were one of the main causes of the Reformation. Martin Luther's post on the church door was, of course, completely inadequate to put an end to indulgences. And there are other sorts of them still being created. "Solar Renewable Energy Certificates" seem like an indulgence market. -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: LCM auction
Unless the museum has an large enough endowment to take care of itself and grow it will fail. I'm sure even the Smithsonian discards items that is can no longer afford to house. And that is after it has sat in storage for years. Whether publicly, privately or government funded expenses and the need for space and man power always increase. Maybe we need a new law, we will call it Allen's law and it is directly related to Moore's law. As computers become obsolete faster and faster the space, time and money to preserve them increases respectively. On 8/29/2024 10:48 AM, Paul Koning via cctalk wrote: On Aug 29, 2024, at 10:45 AM, John Foust via cctalk wrote: At 07:11 AM 8/29/2024, cz via cctalk wrote: The purpose of a museum is to destroy history. Ridiculous. Do the math. If there was a computer so magical and historically significant because only 100 of them were made, and 95 of them were scrapped long ago by individual and corporate owners, and one made it into a "museum," why aren't you equally blaming the people who tossed the 95? At least the museum tried to save it. Did it, though? The attempt may have been made by the collector who donated it, and the museum may be the one who reneged on the commitment to preserve. paul
[cctalk] Re: LCM auction
Doug, I will call Sallam in a little bit. Thank you, Mike On 8/23/2024 8:23 AM, Paul Koning via cctalk wrote: On Aug 17, 2024, at 7:17 PM, John Herron via cctalk wrote: I still remember how amazing it was to watch the Linc-8 at VCF (west) 10 being troubleshot by previous developers. I swear I stood there (trying to be out of the way) longer than most exhibits just in amazement how they were looking at map size schematics and running test programs that still felt like futuristic science fiction. That reminds me of the PDP-11 20th anniversary event at DECUS (in New Orleans, I think) where we (RSTS team) brought in an 11/05 and tried to get it to run RSTS-11 V4A. The machine was having trouble, including a DECtape that was acting very strangely indeed. At one point Tom Stockebrand walked by and glanced at the system. Then he looked more closely, inspecting the indicator lights on the DECtape drive. Then he commented "wait... that should not be possible!" I think he spent a while helping debug the machine. In the end I think we had it running a "blinkenlights" loop since it couldn't boot a full OS. But it was neat to have the white-haired inventor of DECtape help us with that machine. paul
[cctalk] VCF Midwest DEC "Nut" Party
For all of you who are DEC computer nuts (or aficionados) we will have our second annual DEC "Nut" pizza get together after the show at my house on Saturday (Sept 7th) after 7PM. I am unemployed so I ask all who attend to contribute to the cost of the pizza (beer and pop will be provided). Please see me at the show for my address. I hope to see you there. Mike Katz +1 (773) 414-1044 (Cell)
[cctalk] Re: A little off-topic but at least somewhat related: endianness
Ben, The purpose of the stdint.h file is to allow the programmer ti specify the size of the variables. On some systems is an int 32 bits or 64 bits (or even 16 bits on older systems or 16 bit micros). The size of an int is not specifically defined in the C standard. Especially when doing embedded coding the size of a variable (or the size of the data pointed to by a pointer) is very important. The stdint.h file is created by the authors of the compiler so that the programmer can specify the size of the variable that he wants. /int A/ may or may not be 32 bits but /int32_t A/ will always be 32 bits. This is mostly not a problem on modern 32 bit microprocessors where an int is 32 bits and a short is 16 bits. However, on that system is a long 32 bits or 64 bits? By having the typedefs in the stdint.h file, the programmer can specify the exact size of the variable. On 8/16/2024 1:38 AM, ben wrote: On 2024-08-15 7:46 p.m., Mike Katz wrote: That is the reason for the stdint.h file. Where you specify the width of the variable in bits Looks like a useless file to me. I never liked any the standards made to C after K&R. Seems more driven by the latest crappy hardware intel makes, than a language designed by people who use the product. C++ or JAVA never made sense because every class is too different from any other object.Don't say how windows are a good example of object, they are foobar-ed from the start as they deal in pixels, rather than a fractional screen display.Text windows worked under DOS.something easy to program. I don't want write a whole operating system to use modern software like windows. Grumpy Ben, trying to find a embedded C compiler for the 68000. PS: Perhaps if they had good textbook for C and the different standards I might view modern C with less distrust.
[cctalk] Re: A little off-topic but at least somewhat related: endianness
Fred, You are correct in all of your examples. That is why many standards specify things like /multiple function calls should not be used in a single expression/. The compiler will optimize out any unecessarry memory reads and writes so rewriting: X = foo() + bar(); as X = foo(); C += bar(); Will force the correct order of execution of the functions while not taking any more CPU cycles. Mike On 8/15/2024 7:32 PM, Fred Cisin via cctalk wrote: On Thu, 15 Aug 2024, Mike Katz wrote: C has specific specifications for what is promoted when and how. They are not ambiguous just not known by many. I worked for a C compiler company so I'm may be a bit more familiar with the actual C specs and how the compiler works. However, I totally agree with you. I heavily typecast and parenthesize my code to avoid any possible ambiguity. Sometimes for the compiler and sometimes for someone else reading my code. I will readily concede that ANSI C has fewer problems with ambiguous code than the K&R C that I learned. But, for example, in: X = foo() + bar(); has it been defined which order the functions of foo() and bar() are evaluated? Consider the possibility that either or both alter variable that the other function also uses. (Stupidly simpe example, one function increments a variable, and the other one doubles it) As another example of code that I would avoid, int x=1,y=1; x = x++ + x++; y = ++y + ++Y; give 2, 3, 4, or 5? is heavily dependent on exactly when the increments get done. But, thorough careful typecasting, use of intermediate variables, etc. can eliminate all such problems. 'course "optimizing compilers" can (but shouldn't) alter your code. If you don't explicitly specify exactly what you want, "C gives you enough rope to shoot yourself in the foot" (as Holub titled one of his books) But, I've always loved how easily C will get out of the way when you want to get closer to the hardware. -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: A little off-topic but at least somewhat related: endianness
I have written several coding standards and comments are always primary in importance. The Misra C standard does a pretty good job of forcing the programmer to aim for something other than their foot with their rope 🙂 I am amazed at how many fresh outs I have met who really can't program their way out of a paper bag. On 8/15/2024 7:46 PM, Fred Cisin via cctalk wrote: When I was teaching C, it was sometimes quite difficult to help students who had firm assumptions about things that you can'r assume. Such as the sequence of operations in the multiple iterations examples that we both used. I tried desperately to get them to do extensive commnets, and use typecasts even when they could have been left out.
[cctalk] Re: A little off-topic but at least somewhat related: endianness
That is the reason for the stdint.h file. Where you specify the width of the variable in bits int8_t, int16_t, uint16_t. etc. On 8/15/2024 8:39 PM, ben via cctalk wrote: On 2024-08-15 6:46 p.m., Fred Cisin via cctalk wrote: When I was teaching C, it was sometimes quite difficult to help students who had firm assumptions about things that you can'r assume. Such as the sequence of operations in the multiple iterations examples that we both used. I tried desperately to get them to do extensive commnets, and use typecasts even when they could have been left out. I keep assuming C is still 16 bit K&R. Software tends to depend on the fact bytes are 8 bits, and every thing a 2,4,8 bytes wide and the newest hardware/software/underwear^H^H^H^H^H^H^H is the best. PL/I tried to fit data types, to have variable width that I think was a good idea. foobar Binary:unsigned:36 bits:mixed endian,volatile,module blah,dynamic array x y z. It least then you know what foobar does. HUMBUG foo, not so clear. Ben, still thinking 18 bit computers are just the right size for personal use, and some day I will have hardware.
[cctalk] Re: A little off-topic but at least somewhat related: endianness
Fred, That is true, Order of expression is undefined between execution points that is why the following statement can produce different results on different compilers: A = 1; F = A++ * A++; Without the use of parenthesis the is no way for the user to know beforehand what the value of F will be. The only guarantee is that when the before the next instruction is executed the all postfix operators will be evaluated prior to the start of the next C statement. As a general rule rvalue expressions are calculated by the pre-compiler and not the compiler. So the line: ulDays = ulSeconds / ( 60 * 60 * 24 ); Would be converted by the precompiler to: ulDay = ulSeconds / 86400; The calculation of the lvalue ulSeconds / 86400 will be handled at run time. However, if ulSeconds is defined as a const it is possible that a smart precompiler will do the entire calculation and only the assignment will be done at runtime. It is possible that the volatile keyword might cause the order of expression to be altered. uint32_t * volatile ulpDMAAddress = 0x; // Note this is a volatile pointer and NOT a pointer to volatile data. uint32_t *ulpMyPointer; ulpMyPointer = *ulpDMAAddress++ + *ulpDMAAddress++; My mind is getting numb just looking at that code. Suffice it to say that using multiple prefix/postfix operations in a single execution point is heavily deprecated because the actual results are implementation defined and my even be different depending upon what other math surrounds it. Another implementation specific feature of C is the order of bits in bit fields. They can be assigned from most significant to least significant or vice-versa. It is totally up to the compiler. As Allan Holub says C and C++, in his book of the same name, gives the programmer "Enough Rope To Shoot Yourself in the Foot" On 8/15/2024 6:45 PM, Fred Cisin via cctalk wrote: It is not the hardware that is at fault. If anybody else is to blame, it is the compiler. On Thu, 15 Aug 2024, Paul Koning wrote: More likely the language designers, assuming the compiler doesn't have a standards violation in its code. In the case of C, the type promotion rules that were just explained are rather bizarre and surprising. Other languages do it differently, with perhaps fewer surprises. Some define it very carefully (ALGOL 68 comes to mind), some not so much. C very explicitly leaves some thing undefined, supposedly to work with more machines, and Kernighan & Ritchie say that it is the responsibility of the programmer to create unambiguous code. for example, evaluation of expressions in the lvalue might be done before OR after evaluation of expressions in th rvalue Some other languages are much stricter on types, etc. and have fewer ambiguities.
[cctalk] Re: A little off-topic but at least somewhat related: endianness
Will according to the ISE/IEC 9899:2018 C Standard section 6.3.1.8 you
are incorrect. Please the the emboldened line below.
6.3.1.8 Usual arithmetic conversions
1. Many operators that expect operands of arithmetic type cause
conversions and yield result types in
a similar way. The purpose is to determine a common real type for the
operands and result. For the
specified operands, each operand is converted, without change of type
domain, to a type whose
corresponding real type is the common real type. Unless explicitly
stated otherwise, the common
real type is also the corresponding real type of the result, whose type
domain is the type domain of
the operands if they are the same, and complex otherwise. This pattern
is called the usual arithmetic
conversions:
First, if the corresponding real type of either operand is long double,
the other operand
is converted, without change of type domain, to a type whose
corresponding real type is
long double.
Otherwise, if the corresponding real type of either operand is double,
the other operand is
converted, without change of type domain, to a type whose corresponding
real type is double.
Otherwise, if the corresponding real type of either operand is float,
the other operand is
converted, without change of type domain, to a type whose corresponding
real type is float.64)
Otherwise, the integer promotions are performed on both operands. Then
the following rules
are applied to the promoted operands:
* If both operands have the same type, then no further conversion is
needed.*
Otherwise, if both operands have signed integer types or both have
unsigned integer
types, the operand with the type of lesser integer conversion rank
is converted to the type
of the operand with greater rank.
Otherwise, if the operand that has unsigned integer type has rank
greater or equal to
the rank of the type of the other operand, then the operand with
signed integer type is
converted to the type of the operand with unsigned integer type.
Otherwise, if the type of the operand with signed integer type can
represent all of the
values of the type of the operand with unsigned integer type, then
the operand with
unsigned integer type is converted to the type of the operand with
signed integer type.
Otherwise, both operands are converted to the unsigned integer type
corresponding to
the type of the operand with signed integer type.
2. The values of floating operands and of the results of floating
expressions may be represented in
greater range and precision than that required by the type; the types
are not changed thereby. The
cast and assignment operators are still required to remove extra range
and precision. See
5.2.4.2.2 regarding evaluation formats.
On 8/15/2024 6:54 PM, Will Cooke via cctalk wrote:
On 08/15/2024 6:10 PM EDT Mike Katz via cctalk wrote:
I'm pretty certain you are wrong about the byte case below. The C standard
says something about no math will be done smaller than a short. I don't have
it handy so can't quote exactly.
But what that means is before the two bytes are added, they are promoted to
short / uint16_t and then added.
int foo( void )
{
uint32_t Long1 = 10;
uint32_t Long2 = 20;
uint16_t Short1 = 10;
unit16_t Short2 = 20;
uint8_t Byte1 = 10;
uint8_t Byte2 = 20;
//
...
// Everything to the right of the equals will not be promoted at
all, the math will be performed and the result will be promoted to a
uint16 when assigned.
//
Short1 = Byte1 + Byte2;
In this program segment:
uint8_t a = 255;
uint8_t b = 255;
uint16_t c = 0;
c = a + b;
printf("c: %d \n", c);
it will print 510 instead of the 254 that would result if it were added as
bytes.
Will
Grownups never understand anything by themselves and it is tiresome for
children to be always and forever explaining things to them,
Antoine de Saint-Exupery in The Little Prince
[cctalk] Re: A little off-topic but at least somewhat related: endianness
Mr. Grumpy :) C has specific specifications for what is promoted when and how. They are not ambiguous just not known by many. I worked for a C compiler company so I'm may be a bit more familiar with the actual C specs and how the compiler works. However, I totally agree with you. I heavily typecast and parenthesize my code to avoid any possible ambiguity. Sometimes for the compiler and sometimes for someone else reading my code. Mike On 8/15/2024 6:09 PM, Fred Cisin via cctalk wrote: On Thu, 15 Aug 2024, Paul Koning via cctalk wrote: I don't know about the VAX,but my gripe is the x86 and the 68000 don't automaticaly promote smaller data types to larger ones. What little programming I have done was in C never cared about that detail. Now I can see way it is hard to generate good code in C when all the CPU's are brain dead in that aspect. It is not the hardware that is at fault. If anybody else is to blame, it is the compiler. int8 A = -1; uint8 B = 255; /* Those have the same bit pattern! */ int16 X; int16 Y; X = A; Y = B; will X and Y have a bit patterns of , or If you expect them to be "promoted", you are giving ambiguous instructions to the compiler. The CPU isn't ever going to know. THAT is why explicit typecasting is the way to go. -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: A little off-topic but at least somewhat related: endianness
On 8/15/2024 3:41 PM, Sean Conner via cctalk wrote: It was thus said that the Great ben via cctalk once stated: I don't know about the VAX,but my gripe is the x86 and the 68000 don't automaticaly promote smaller data types to larger ones. What little programming I have done was in C never cared about that detail. Now I can see way it is hard to generate good code in C when all the CPU's are brain dead in that aspect. char *foo, long bar; ... foobar = *foo + bar is r1 = foo r3 = * r1 r2 = bar sex byte r3 sex word r3 r4 = r3 + r2 foobar = r3 what I want is bar = * foo + bar nice easy coding. What CPUs did it correctly? And how did they handle signed vs. unsigned promotion? unsigned char *ufoo; unsigned long ubar; ufoobar = *ufoo + ubar; // *ufoo will be promited to an unsigned long, added to ubar and the result stored in ufoobar withouut any promotion or demotion (assuming ufoobar is an unsigned long) signed char *foo; signed long bar; foobar = *foo + bar; // *foo will be promoted to a long, added to bar and the result stored in foobar without any promotion or demotion (assuming foobar is a long) -spc
[cctalk] Re: A little off-topic but at least somewhat related: endianness
When signed and unsigned values (variables or literals) of the same size are combined the compiler assumes that all of the values are signed. This can yield a problem if the unsigned integer is large enough that the most significant bit is set because this bit indicates sign. for example: uint8_t bValue = 128; int8_t bValue1 = -128 Both have the same value in memory (0x80). On 8/15/2024 3:52 PM, Paul Koning via cctalk wrote: On Aug 15, 2024, at 4:41 PM, Sean Conner via cctalk wrote: It was thus said that the Great ben via cctalk once stated: I don't know about the VAX,but my gripe is the x86 and the 68000 don't automaticaly promote smaller data types to larger ones. What little programming I have done was in C never cared about that detail. Now I can see way it is hard to generate good code in C when all the CPU's are brain dead in that aspect. char *foo, long bar; ... foobar = *foo + bar is r1 = foo r3 = * r1 r2 = bar sex byte r3 sex word r3 r4 = r3 + r2 foobar = r3 what I want is bar = * foo + bar nice easy coding. What CPUs did it correctly? And how did they handle signed vs. unsigned promotion? unsigned char *ufoo; unsigned long ubar; ufoobar = *ufoo + ubar; signed char *foo; signed long bar; foobar = *foo + bar; -spc Obviously, "correctly" is in the eye of the beholder. You can do size extension, signed or unsigned, on any computer. How complicated it is depends on the machine. For example, on VAX there are instructions for signed as well as unsigned promotion (CVTxy and MOVZxy respectively). On PDP11, MOVB into a register does sign extension; unsigned promotion requires two instructions but that's no big deal. And of course, promotion to bigger types requires multiple instructions either way since you're now dealing with multiple registers. Unsigned promotion on a CDC 6600 is one instruction; signed requires three. paul
[cctalk] Re: A little off-topic but at least somewhat related: endianness
I'm afraid you might not understand how promotion works in C. Promotion
has nothing do to with the word size of the machine it's running on.
Within the expression, all intermediate values and literals are promoted
to the smallest type that can contain the largest value/literal in the
expression. As a general rule numeric literals (actual numbers typed
in) are the default integer size of the machine (32 bits on most modern
processors and compilers). This can be changed with pragmas or command
line options on most C compilers.
This may or may not be promoted or demoted to store the result in its
final destination.
For example:
#include "stdint.h"
int foo( void )
{
uint32_t Long1 = 10;
uint32_t Long2 = 20;
uint16_t Short1 = 10;
unit16_t Short2 = 20;
uint8_t Byte1 = 10;
uint8_t Byte2 = 20;
//
// Everything to the right of the equals is promoted to a uint32,
the math will be performed and then the result will be truncated to a
uint8_t when assigned.
//
// This may also generate a compiler warning due to not
typecasting the result on the right side of the equals.
//
Byte1 = Short1 + Long1;
//
// Everything to the right of the equals will be promoted to a
uint16, the math will be performed and then the result will be promoted
to a uint32 when assigned
//
Long1 = Short1 + Byte1;
//
// Everything to the right of the equals will not be promoted at
all, the math will be performed and the result will be promoted to a
uint16 when assigned.
//
Short1 = Byte1 + Byte2;
Generally numeric literals (actual numbers typed in) are the default
integer size of the machine (32 bits on most modern processors and
compilers). This can be changed with pragmas or command line options on
most C compilers.
I hope this clears things up?
On 8/15/2024 2:41 PM, ben via cctalk wrote:
On 2024-08-15 11:00 a.m., Paul Koning via cctalk wrote:
The short answer is "it's historic and manufacturers have done it in
different ways".
You might read the original paper on the topic, "On holy wars and a
plea for peace" by Danny Cohen (IEN-137, 1 april 1980):
https://www.rfc-editor.org/ien/ien137.txt
Not reading the paper, I would say it is more the case having short
data types (little) and FORTRAN packing 4 characters in word (big).
I don't know about the VAX,but my gripe is the x86 and the 68000 don't
automaticaly promote smaller data types to larger ones. What little
programming I have done was in C never cared about that detail.
Now I can see way it is hard to generate good code in C when all the
CPU's are brain dead in that aspect.
char *foo, long bar;
... foobar = *foo + bar
is r1 = foo
r3 = * r1
r2 = bar
sex byte r3
sex word r3
r4 = r3 + r2
foobar = r3
what I want is
bar = * foo + bar
nice easy coding.
And yes, different computers have used different ordering, not just
characters-in-word ordering but bit position numbering. For example,
very confusingly there are computers where the conventional numbering
has the lowest bit number (0 or 1) assigned to the most significant
bit. The more common numbering of 0 for the LSB gives the property
that setting bit n in a word produces the value 2^n, which is more
convenient than, say, 2^(59-n).
Real computers are 2^36 from the 50's.
Big iron is the 60's. :)
paul
[cctalk] Need Car/Truck space for two DEC size boxes from Chico, Ca to the Chicago area
I recently purchased a PDP-8/L and an expansion box from a very nice gentleman in Chico, California and I need a way to get it to Chicago. If you are driving from Chico, California to Chicago (for VCFMW or just because) and you have room in your car/truck for two 10" High x 19" wide x 24" deep metal boxes plus two small cardboard boxes and are willing to make a stop in Chico to pick up the items I would be very happy to contribute to gas/truck rental. I can drive to meet you if you are coming withing 100 miles of Chicago. Please contact me off list at bit...@12bitsbest.com to make arrangements. Thank you, Mike.
[cctalk] Re: FIDONET for shipping? Was: what to do with our "treasures"
Rather than trying a kind o fidonet like transportation system why don't we work together to negotiate a rate with a national electronic equipment mover. Maybe through the ausipices of an existing non-profit organization like the VCFED or maybe an organization of museums. Good luck. On 7/2/2024 12:33 PM, Sellam Abraham via cctalk wrote: On Tue, Jul 2, 2024 at 9:27 AM Bill Degnan via cctalk wrote: A lot of us have storage spaces and we could all possibly work together to create a FIDONET of shipping vintage computer items from one node to the next. I know it's probably in practice impractical on a large scale perhaps but theoretically this might be a nice way to get items slowly and cheaply from point A to point B (via several less expensive hops). Bill This is something I've thought about from time to time. It can more readily be accomplished today with the increased interest and participation in this hobby: there are a lot more collectors out there now across the entire USA and Canada. Sellam
[cctalk] Re: what to do with our "treasures"
Look in the for sale forums at vcfed.org. ' The Vintage Computer Federation. On 6/27/2024 10:46 AM, Mark Linimon via cctalk wrote: On 06/27/2024 9:36 AM CDT Bill Gunshannon via cctalk To date, I have sold nothing. I once went back to the list that suggested I use ebay to report my failure only to be greeted with, "Well, what did you expect. You are not an established seller." I also have a whole pile of stuff that needs to go "somewhere". Sounds like we more need a "make offer" page. Is there somewhere on the net that already does this? mcl
[cctalk] Re: Lunar Lander, bug
I remember running this program at school in the mid 1970's. This runs on 4K Focal '69 without the extended functions enabled. So it should run on a 4K PDP-8/L. I think I might have actually run it on a 4K PDP-8/L with an ASR-33 Teletype sometime between 1972 and 1975. I know I ran it on a PDP-8/E with 12K and a TD8E DecTape system based Edusystem 20 in 1975. It was available as FOCAL8-81 from DECUS (Submitted 20-Jan-1970): Abstract: This program realistically simulates an Apollo moon landing using NASA figures. It begins with module at fJ seconds, 120 miles above the moon, carrying 16000 pounds of fuel, with a velocity of 2600 miles per hour. Upon radar checks of velocity, altitude, remaining fuel, and time each 10 seconds, you /nay decide upon fuel rate for next time interval. The object is to land safely on the moon. RESTRICTIONS You cannot retain FOCAL's extended functions (LOG, EXP, etc). I have attached a scan of the DECUS Program Library documentation on it. This has the source on page 4 of the PDF On 6/17/2024 4:40 AM, cz via cctalk wrote: Didn't know the source code had been released in FOCAL. I wonder if it will run on a 4k pdp8/L. One way to find out. On 6/17/2024 4:38 AM, emanuel stiebler via cctalk wrote: Interesting reading, as I believe, we all played it at least once :) https://arstechnica.com/gaming/2024/06/retired-engineer-discovers-55-year-old-bug-in-lunar-lander-computer-game-code/
[cctalk] Re: Intel 8086 - 46 yrs. ago
Even earlier than the TPU on the 68332 is the communications co-processor built into the 68302. This predate the entire CPU-32 family. On 6/13/2024 10:56 AM, Adrian Godwin via cctalk wrote: Even without things like system management mode, there are lots of speed-up features on modern processors that result in variable execution times - things like caching and pipelining. With sufficient care these can sometimes be made predictable but there are certain common needs that have always found it better to have a dedicated peripheral to do these jobs. The first common one was possibly the Motorola TPU (time processing unit) on the 68332 and others. The target application was injection timing for automotive ECUs and although external dedicated logic such as FPGAs have also been used, the microprogrammable peripheral has continued to be a feature of some relatively common processors. The TI processor in the beaglebone has PRIs, the raspberry pi Pico RP2040 has PIOs, and there's also the parallax propellor which has 8 high speed parallel processors running at 80MHz and able to interleave operations on common ports : a newer version has iirc a 1Ghz clock. Another technique has 'abused' dma and serial data peripherals on esp8266, esp32 and Teensy processors to produce pulse trains for WS2812 LED control at IIS clock rates. They construct the desired output waveform in memory and DMA them out, though this may be unsuitable for servo control as the buffers are large, giving good precision but poor latency. On Thu, Jun 13, 2024 at 4:40 PM Jon Elson via cctalk wrote: On 6/12/24 09:52, Jon Elson via cctalk wrote: On 6/12/24 03:02, Peter Corlett via cctalk wrote: Fun factoid: despite modern x86 being clocked ~1000x faster than ye olde 6502, there's not much in it between them when it comes to interrupt response time. If all goes well, x86 takes "only" a hundred-ish cycles to do its book-keeping and jump to the ISR, but if SMM is active (spoiler: it always is and you can't turn it off) then it introduces a massive amount of extra jitter and all bets are off. Well, actually the Pentium classic was supposedly designed as the flight computer for the F-15, and had VERY good interrupt response time of around 5 us. We know all about this as we used it with real time Linux in CNC motion control systems. A big concern was what was the delay and jitter from the RTC triggering an interrupt to when the servo position counters were read. It has been a struggle to maintain this level of low jitter with newer processors, but we have found quite a few that can do it. AACK! Sorry, that was supposed to be F-16! Jon
[cctalk] Re: teletype roll as an RF termination load
Maybe they are thinking that because it is oil it will work like an oil can load. Sound to me like the originator of this is a big load of dummy🙂 On 6/12/2024 8:28 PM, mark audacity romberg via cctalk wrote: Yeah, something’s missing here, teletype paper is for sure not good as a dummy load.
[cctalk] Re: TVs [was: Pragmatically [was: Experience using an Altair 8800 ("Personal computer" from 70s)]
I believe that place on Elston was either Joseph Electronics or The American Science Center depending on whether is was in Chicago or Niles. On 5/28/2024 8:06 PM, CAREY SCHUG via cctalk wrote: We spent 64-65 in japan, bought a TV, brought it back, channels were different, so i bought a surplus tv tuner at that place on elston in Chicago an replaced it. These were tubes. I started in electronics taking apart the 8" tv we were given, which had two complete chassis, each with a hefty power supply, mostly full size tubes, IIRC. --Carey
[cctalk] Re: Pragmatically [was: Experience using an Altair 8800 ("Personal computer" from 70s)]
Fred, I'm sorry but those arguments are religion to most of us and the clear answer has already been decided (tongue firmly implanted in cheek)😛 1. Between Vi and EMACS - Any editor where you have a cursor movement mode that is separate from edit mode (since the invention of arrow keys or the control key) just isn't a real editor. 2. Between Big Endian and Little Endian - Big endian is easier to read for us dumb humans but little endian was easier to implement on early hardware. I want to add to this argument and ask Is bit 0 the high order bit (like on the PDP-8) or the low order bit (like on the 6809)? 3. Between the 6502 and the Z-80 the 6809 wins hands down every time. As for the first personal computer, no one has been able refuted my claim that the Antikythera Mechanism is not only the first Personal Computer but also first portable computer 🤣 On 5/28/2024 5:10 PM, Fred Cisin via cctalk wrote: On Tue, 28 May 2024, Sellam Abraham via cctalk wrote: How about can we be done with this now? :D Sorry, but "FIRST" and "PERSONAL" are permanent topics, along with emacs V VI, big-endian/little-endian, Mac/PC, 6502/Z80, etc.
[cctalk] Re: terminology [was: First Personal Computer]
Paul, you said:/ / /I'd say an OS is a software system that runs on bare metal (or equivalent, like a VM) and offers a set of services intended to make creating and running applications easier. In that sense, RT-11 SJ or OS/360 PCP are operating systems, just as Linux is. QRQ is on the edge (it's written for a single application). Similarly, I would not call FIG-FORTH an OS, nor those other FORTH systems, though admittedly it's also a bit fuzzy. / If the file system and basic I/O functions drivers are in ROM what is the difference between a BIOS and an Operating System. Technically speaking, for some, the BIOS offers a hardware abstraction level to some more generic software that runs on top. BIOS means Basic Input Output System. Is that restricted to the console only? Some systems run their entire "Operating System" out of ROM? Let's take a very simple computer, the HP-41C Calculator. The internal 12K or ROM handled all of the keypad I/O, display I/O, math functions and programming functions. Each device added contained all of it's drivers in ROM. There was never an "Operating System" to load but with additonal hardware/software modules even reading and writing to floppy disks and mini data cassettes was supported. The 12K main ROM and how the expansion hardware/ROM integrated into it was definitely an operating system. On the IBM-PC most boards (that were not just multi I/O or RAM boards) came with their own drivers in ROM as well and were even called bios extensions. The big difference between the PC and the HP-41C that the PC needed to load the file system handler (and others as time when on) from disk to run. Whereas the HP-41C never needed to "bootstrap" from some kind of media. By your definition many BIOS's are really operating systems. And if I really want to pick nits, what you defined as an Operating System is really an application that uses the BIOS Operating System. Yes, I know, not all BIOS's have enough functionality to qualify as an operating system. To spark even further debate, does an operating system require file system capabilities. Many do not. This furthers my supposition that the BIOS is really the operating system and what you are calling an operating system is merely an application using the BIOS API for the required services.🙂 My comments are not intended to inflame but rather to cause further discussion. On 5/28/2024 2:38 PM, Paul Koning via cctalk wrote: On May 28, 2024, at 3:24 PM, John via cctalk wrote: From: ben To:cctalk@classiccmp.org Subject: [cctalk] Re: terminology [was: First Personal Computer] The third thing is a real OS. Nobody has one, as a personal computer. CP/M and MSDOS does not handle IRQ's. Unix for the PDP-11 is real operating system but not personal as it requires a admin,and a swapping media. This an auld refrain among *nix partisans of the ESR type, but I've yet to hear someone offer up a real defense of it. Even putting aside what "handles IRQs" means here (yes, strictly speaking the IRQs on the IBM PC are handled by the BIOS and/or add-on drivers/utilties, but DOS most certainly makes use of the facilities provided,) why does that make it "not a real OS?" What does PDP-11 Unix provide which MS-DOS doesn't to make one "real" and the other not? Certainly, nothing about a single-tasking single-user text-based environment *requires* interrupt-based I/O, even if it may smooth out performance in some aspects. ... Or is it multi-tasking capability itself that makes the difference? Can't see why that should be the case; it's definitely convenient, but as one person can only be doing so much at any given time, it's also hard to see that as a *requirement.* So what, then, consitutes a Real Operating System, and why? Is RT-11 a "real operating system"? What about RT-11 SJ? I would consider it to be one. For that matter, what about OS/360 PCP? That's a single task OS, just like RT-11 SJ only much less efficient. Is FIG-FORTH an OS? What about POLYFORTH or ZeptoFORTH? The picture gets particularly muddled when you look at RTOS. For example, it's well known in hard real-time OS that using interrupts is not necessarily a good plan. A very successful storage system I worked on ran on a dual core MIPS system. One core ran NetBSD; the other ran a home-grown RTOS called QRQ that used a polling loop (and no priorities) rather than interrupts. The benefit of such a design is that its time bounds are easy to establish, unlike interrupt driven systems where that is certainly harder and not always possible at all. I'd say an OS is a software system that runs on bare metal (or equivalent, like a VM) and offers a set of services intended to make creating and running applications easier. In that sense, RT-11 SJ or OS/360 PCP are operating systems, just as Linux is. QRQ is on the edge (it's written for a single application). Similarly, I would not call FIG-FORTH an OS, nor those other FORTH
[cctalk] Re: terminology [was: First Personal Computer]
OS/9 was an incredible operating system for an 8 bit machine. Level 1 was a bit limited. But level II, which could address a megabyte of memory or more, supported multiple tasks, users and intelligent peripherals. It supported applications in ROM and RAM and made full use of all of the advanced capabilities of the 6809 CPU. It was a little bit of a memory hog because code written for it had to be written as position independent code. On the 6809 this could take up more RAM because some of the relative instructions required 16 bits or more to decode. On 5/26/2024 5:49 PM, Fred Cisin via cctalk wrote: "Real OS"? While I don't agree with your specific examples of inadequacies, I will readily concede that nothing so far is ready for the title. On Sun, 26 May 2024, ben via cctalk wrote: CP/M was the cats meyow in the 1970's,but there was other systems out like flex for the 6800, or later OS/9 for the 6809. Don't they get a chance too for real OS. OS/9 was kinda cool, but my Cocos were kinda inadequate hardware to make full use of it. Randy Cook tried to make a "real OS" for the TRS80. But, he never FINISHED [nor documented] TRSDOS, nor VTOS. When LSI commissioned LDOS, as the finishing of TRSDOS/VTOS, they stripped out a lot of the "real OS" features that Randy Cook had intended, but never finished implementing. But, when Radio-shack licensed LDOS, to be TRSDOS 6.0, Randy Cook finally started to receive royalties. -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: terminology [was: First Personal Computer]
i'm sorry but you are misinformed about the HP-41C Calculator. The HP-41 was the first calculator that had Alpha-Numerics. It could very well give text descriptions, text prompts and even manipulate text. It also had a full goto and gosub to alphanumeric labels. It had a very sophisticated programming language that could be user enhanced in both user (FOCAL [No Relation to DEC's Focal]) language and machine language. The user community enhanced the user language through the use of "Synthetic Programming". This is creating additional user commands not originally implemented by HP. It came with four expansion slots built into it for RAM, ROM and peripherals. It supported several different file systems in both RAM and digital media. There was a forth interpreter available for it as well. Here is a list of some of the peripherals available for it (I know there are way more than this list): Direct Plug In: Magnetic Card Reader Bar Code Reader 20 Column Thermal Printer HI-IL (2 wire network) EEPROM Box for Machine Code RAM Box for Machine Code Additional Program Memory Extended Memory ROM Module for user code and machine code (both from HP and user written). HP-IL Peripherals 20 Column Thermal Printer 80 Column Ink Jet Printer Digital Magnetic Tape Drive 3 1/2" Floppy Disk Drive RS-232 Interface IEE-488 (GPIB) Interface Video Interface (40 column, 80 column, graphics) HP-IL Interface for Epson MX-80 dot matrix printer Digital Multimeter Frequency Counter 20 Channel Data Acquisition Box The CPU had a 10 bit instruction word with a 56 bit data word. With a Harvard Architecture (separate RAM and ROM address spaces). The RAM address space was 8192 8 bit bytes. The ROM address space was 65536 10 bit words. With paging the machine code address space was expanded to 192K maximum) That hardly sounds like just a calculator to me. It could be called the first Pocket PC. On 5/26/2024 4:14 PM, CAREY SCHUG via cctalk wrote: if it only manipulates numeric data, it is a calculator. It must be able to search, rearrange look up, compare, and display characters. I would have thought that to be obvious. I don'care if it has 99 terabites of high speed memory and does fourier transforms in minus 0 seconds, if it cannot give a text description of the answer, it is a calculator. Also something about arbritray branches to any location (ok, any executable location if something has separate code and data memory). --Carey On 05/26/2024 3:01 PM CDT Chuck Guzis via cctalk wrote: On 5/26/24 11:11, ben via cctalk wrote: On 2024-05-26 10:56 a.m., Fred Cisin via cctalk wrote: I did use a CP/M machine once, but the 8" drive was a bit sticky. You rap the drive to get it unstuck, but if you rap it too hard the machine would reset. Fred, just forget it. We belong to a bygone era and there's no sense in trying to explain things to the younger folk. However, perhaps someone can tell me why an HP-41 or TI SR-52 isn't a "personal computer"... --Chuck
[cctalk] Re: First Personal Computer
You see, we are back to my original comment. The definition of Personal Computer is quite fluid. Does it have to be called a Personal Computer in advertising literature or does any computer that can be used by a single person, in any environment, constitute a personal computer. If i am writing the definition than my original comment that the Antikythera Mechanism is the first computing device designed to be used by a single person.. To someone else the Altiar is the first personal computer. And to yet, someone else an early PDP or HP computer might be the first personal computer. There are many mechanical and later analog computing devices in use long before the modern digital computer. What about the Hollerith Machine used to count the census from the 1890's to the 1950's. It was a one person calculating machine but since it was used for commercial purposes does that make it a personal computer. When IBM initially released the first PC it was intended not for home use but for business use (for $10,000 1980's dollars). The Northstar Horizon was also marketed as a business computer but used by home S-100 hobbyists. The point, as I stated earlier, is that for every different definition we will find a different result. I guess this means that the definition of personal computer is personal😛 This is written with tongue firmly implanted in cheek. On 5/25/2024 1:27 PM, Jon Elson via cctalk wrote: On 5/25/24 13:05, CAREY SCHUG via cctalk wrote: When announced and sold new, were the SIMON, LINC and G-15 sold and described as, in the exact words, "personal computer"? Did the guy with multiple supercomputers in his basement buy them NEW, to use them for their designed purpose? If not they are just memorabilia, like a victrola. The Bendix G-15 came out in 1956! It cost about $60,000 in 1956 Dollars. The first LINC machines were built at an MIT summer school by grad students who would then take them back to their home institutions and use then in biomedical research labs. The LINCs in this case cost about $50K, and were built starting in 1961-62. The term "personal computer" was not coined until a LONG time after. Jon
[cctalk] Re: terminology [was: First Personal Computer]
I'm sorry but I beg to differ with you here. The DEC PDP line of single user interactive computers (as opposed to batch processing only systems) started in the late 1950's and early 1960's and spawned many generations as well as copies and other companies (Data General being the most well known of these).Yes multi user time sharing operating systems we added later on but initially they were single user interactive, (DEC 10 & 20 excepted).Does a computer lose its "Personal" identification if it can handle multiple users as an option. There were multiple user time sharing Operating Systems for many early personal computers (Unix, Xenix, MP/M, Uniflex, OS/9, etc.). Even the aforementioned PDP computers ran multi-user time sharing systems. Does that, then, invalidate them for consideration as a personal computer? Does that make any Linux machine not a personal computer, by definition, because it can handle more than one user or task? As I have said earlier in this thead and its fore bearers, the term Personal Computer is so non-specific that we can argue from here to Alpha Centauri and back without coming up with an agreed upon definition. So, until a concrete definition can be made, the discussion of the answer is completely moot. I stick by my original challenge, find a calculating device that predates the Antikythera Mechanism (36 BCE). Simple measuring devices like the sun dial and sextant don't count as they don't calculate, they measure. On 5/25/2024 4:26 PM, CAREY SCHUG via cctalk wrote: (Rick--IIRC, some later Curta (knockoffs?) could do square roots too, is that true, do you have one?) OK, I'll loosen up, or make exceptions. Maybe some devices before the altair used the exact or inexact words "personal computer". but they did not "create a market" or lead directly to a series of similar, competing products, and do not come anywhere close to what we think of as a "personal computer" now. The Altair is very different from a modern personal computer, but still has more similarities and a continuous chain of intermediate stages. Part of what makes a personal computer to us is that we can easily switch from one to another. That would not have been possible between the LGP-30, LINC, etc. I still ask the question, what fraction of the G-15, LINC, IBM 610, Programma 101, etc, were purchased as "personal" devices by an individual, for personal use, and from household funds rather than via a corporate (including educational) purchase-order? Other terminology: IIRC the first computers that were sold as "supercomputers" were scalar, maybe with a few more processors than the generation before, but programmed in the same manner. Then shortly came the massively parallel "supercomputers" created from commodity microcomputer chips, and the term supercomputer has transitioned to mean them. --Carey On 05/25/2024 3:33 PM CDT Rick Bensene via cctalk wrote: While the LGP-30(vacuum tube/drum), G-15(vacuum tube/drum), and PB-250(transistor/delay lines) predated it, the ground-breaking Olivetti Programma 101(transistor/delay line) programmable desktop calculator was officially called a "personal computer" in some of its advertising and sales literature. It was introduced in October of 1965. Late in the game as far as single-user, standard AC-line-powered computing devices compared to those machines and probably others, but those machines, AFAIK, were not advertised nor specified as "personal computers". That said, I am much more aware of electronic calculator history than computer history, so I could be entirely biased here. Also, the Programma 101, as I've stated here before, only scratches the definition of a true computer in that it is not capable of handling any data type but floating point binary-coded decimal numbers, has very limited data storage capability, and had no peripheral interfacing capability. There were quite a number of single-user computing devices made and sold that ran on standard AC power, and were vastly more capable than the Programma 101, and predated it, but, AFAIK, were not advertised or particularly marketed as "personal computers". One that comes to mind is the Monroe Monrobot III(vacuum tube/drum), introduced in February, 1955. Another is the IBM 610 "Auto Point"(vacuum tube/drum) computer, introduced in 1957. It was originally named the "Personal Automatic Computer" (PAC) by its designer. I'm sure that there are quite a few other machines developed in the mid-to-late 1950's that would qualify as personal computing devices, but these two are the ones that I'm aware of that seem to fit the bill. Some of these may actually have been capable of manipulating data types other than decimal numbers. In 1962, Casio introduced its AL-1 programmable (up to 360 steps) relay-based electric calculator. It was definitely intended as a personal computing device, and calculations could be performed manually from a keyboard much
[cctalk] Re: First Personal Computer
Now that is an interesting refinement. Limiting to 1800 VA, most likely eliminates almost anything vacuum tube based. My 1974 PDP-8/E computer alone (not counting external storage devices) was rated at 115V @ 10A. I don't know what the power factor of it is but that is 1150 Watts. Does that count? Technically I don't need any peripherals to program it or get the program results. I just use the front panel. Does that 1800VA include any necessary peripherals such as terminals, CRT's, disk drives, tape drives, etc? See, even that definition is really non-specific and open to interpretation. Should we add a limitation on volume occupied as well? This would eliminate many rack or multiple rack computers. What about memory type? Before semiconductor RAM and CORE there was serial, drum, tape and mechanical memory systems Does it have to be a digital computer. There we many table top analog computers in the 50's and 60's. Even Heathkit made some. Does the output need to be text (What about an analog computer with a digital nixie tube display)??? Everyone has their own definition of what a Personal Computer is to them. It's all subjective. How much computing power and electricity are we using trying to identify something whose mere definition is so subject to interpretation? On 5/25/2024 4:57 PM, Chuck Guzis via cctalk wrote: On 5/25/24 13:41, Fred Cisin via cctalk wrote: On Sat, 25 May 2024, Chuck Guzis via cctalk wrote: . . . or 100V or 220V in locations where those are the standard for household residential wiring. Woulld not want to automatically exclude UK machines, such as the Sinclair doorstop wedge. Okay, I'll refine it for the international crowd. Anything that requires over 1800 VA to run isn't a "personal computer" That's about 8 amps for the 220 volt world. --Chuck
[cctalk] Re: Help? Programming SCM90448 EPROMs
I have an old Logical Devices Inc, Gangpro 8 with DIP sockets on it. What package is this part? Is it compatible with anything more widely known? On 5/25/2024 12:23 PM, Glen Slick via cctalk wrote: On Sat, May 25, 2024 at 6:27 AM emanuel stiebler via cctalk wrote: Hi all, anybody in the US could program some SCM90448 EPROMs for me? None of my programmers I have here, can do it. Some old, trusty DATA I/O ??? What is an SCM90448? Can you find a datasheet for that part? I cannot.
[cctalk] First Personal Computer
The problem with this debate is that the definition of Personal Computer is totally fluid and can be written so that the writers opinion is fact. Each computer system has contributed, in some way, to those that followed. If you really want say what is the first "personal" computing machine that did not require manual manipulation (like an abacus) it would have to be the Antikythera Mechanism. This orrery (model of the solar system) was built around 35 BC. Yes is was an analog computer but technically it was the first personal computer (single user, autonomous, hand held and portable too). https://www.scientificamerican.com/article/an-ancient-greek-astronomical-calculation-machine-reveals-new-secrets/ https://en.wikipedia.org/wiki/Antikythera_mechanism Ok, all of you computer brains out there, find me something older that matches this (I'm sorry but the sun dial, sextant and compass don't count because they don't calculate they only indicate). Tongue firmly implanted in cheek 😛😂 On 5/24/2024 11:14 AM, Sellam Abraham via cctalk wrote: On Fri, May 24, 2024 at 8:34 AM Chuck Guzis via cctalk < cctalk@classiccmp.org> wrote: On 5/24/24 07:57, CAREY SCHUG via cctalk wrote: (I could be mistaken about the mentioned 8008 device, but I think that was a training device, no?) Do your homewoork--the MCM-70 ran APL, had cassette storage and a display and keyboard. The MITS 8800 had nothing other than RAM and a CPU. APL would have been a distant dream. Of course, the MCM0/70 was Canadian, and not USAn... --Chuck This is on the Canonical List of ClassicCmp Debate Topics and is a dead horse so beaten that there's nothing left but teeth and fur at this point. Sellam
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
When my wife (now my ex-wife) told me during a move that my 2 PDP-8/E racks were not going to the new apartment because there wasn't room for her roll top desk and my computer. And told me "they go or you go with them but they are not moving with us", I should have seen the signs and gone with them. That would have saved me a bunch of money in the divorce AND I would still have those beautiful PDP-8's. I'm still trying to recover from that one. On 5/23/2024 7:04 PM, Fred Cisin via cctalk wrote: On Thu, 23 May 2024, Chuck Guzis via cctalk wrote: I couldn't wait to show it to a female working in my section. She dropped by my apartment, took one look at the thing sitting on my kitchen table and burst out laughing. "That's not a computer; it's a toy!" was her withering reaction. I don't know if my male ego ever recovered from that. And I *hated* the DRAM boards. Be very thankful that it was before you had more invested in the relationship. I almost failed to heed the warning (although FAR less personally humiliating), when a new interest thought that "Hitchhiker's guide To The Galaxy" was "stupid". -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: Random items on Pascal #6
Nicholas Wirth in his paper on Modula-2 about fixing the flaws in Pascal. In planning Modula-2, I saw it as a new version of Pascal, updated to the requirements of the time, and I seized the opportunity to correct various mistakes in Pascal’s design, such as, for example, the syntactic anomaly of the dangling “else”, the incomplete specification of procedure parameters, and others. Apart from relatively minor corrections and additions the primary innovation was that of modules. On 5/9/2024 3:45 PM, Fred Cisin via cctalk wrote: OK This seems to be the one that the list choked on (possibly due to special quote characters? On Thu, May 9, 2024, 2:07 AM david barto via cctalk wrote: At Ken Bowles retirement from UCSD (Ken was the lead of the UCSD Pascal Project) he related a story that IBM came to UCSD after being "rejected" by DR to see if the Regents of the University would license UCSD Pascal (the OS and the language) to IBM for release on the new hardware IBM was developing. The UC Regents said "no" He was quite sad that history took the very different course. well, it wasn't quite a "rejected by DR". But, the culture clash certainly did strengthen IBM's desire for CP/M alternatives. And, they DID cut a deal with Softech/UCSD-Regents to have UCSD P-system as one of the original operating systems for the 5150. The "very different course" of the market going with CP/M and MS-DOS, rather than P-System, was due to many factors. -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: FWIW CD & DVD demagnitizitation [was: Double Density 3.5" Floppy Disks]
This is an article on it but I still think it's total bunk: https://www.gcaudio.com/tips-tricks/cd-dvd-demagnetization/ On 5/9/2024 9:04 AM, Antonio Carlini via cctalk wrote: On 09/05/2024 14:28, Alexander Schreiber via cctalk wrote: German snake oil wizards to the rescue! The "Atomstromfilter" (nuclear power filter) joke product has been making the rounds in Germany for at _least_ 20+y now:https://traumshop.net/produkt/atomstromfilter/ It claims to filter power generated by nuclear power plants out of your power flow at the wall socket ;-) Sorry, but that's clearly rubbish: it's way, way too cheap. Mind you, there are none on eBay UK, so maybe I could put some up at a bargain price ... £3500 too much? (I was going to add a tin foil hat too, to save on postage, but those are already on eBay :-() Antonio
[cctalk] Re: APL (Was: BASIC
There is scientific proof that studying music helps with math aptitude and vice versa. On 5/8/2024 9:30 AM, Paul Koning via cctalk wrote: On May 8, 2024, at 10:25 AM, Harald Arnesen via cctalk wrote: Paul Koning via cctalk [07/05/2024 19.31]: (Then again, I had a classmate who was taking a double major: math and music composition...) Mathemathics and music is not a rare combination - see Tom Lehrer, for instance. -- Hilsen Harald My wife (a voice major) pointed out that instrumental music majors tend to be good at math; voice majors not so much. paul
[cctalk] Re: Double Density 3.5" Floppy Disks
I also have one of those from Radio Shack that I have had for more than 30 years. On 5/6/2024 8:30 PM, Chuck Guzis via cctalk wrote: On 5/6/24 15:12, Fred Cisin via cctalk wrote: Radio Shack used to sell a "Bulk Tape Eraser". I gave mine to the college. Those are on eBay, and even Amazon. I've had one of those for years. Resembles a kitchen Mixmaster without the beaters. The problem is that it has a limited working period of about a minute before it gets too hot and the thermal cutout stops the fun. --Chuck
[cctalk] Re: 5,34 Petaflop System Cheyenne
I wonder if some intermediary is buying it for a country that cannot legally purchase something like that from the USA. I'm not normally a conspiracy guy but why would any normal company pay half a million dollars for something that could be produced with today's technology for considerably less? On 5/3/2024 6:57 PM, Gavin Scott via cctalk wrote: Sold at $480,085.00. On Fri, May 3, 2024 at 6:22 PM Gavin Scott wrote: On Fri, May 3, 2024 at 5:14 PM Liam Proven via cctalk wrote: Bad news... But does he have 8,000 of them haha. Auction is at $435K now (past the end time) with multiple active bidders extending it.
[cctalk] Re: CP/M
CP/M (Originally Control Program/Monitor later Control Program for Microcomputers) we developed by Gary Killdall in at Digital Research, Inc. 1974. CP/M-86 was released in 1981. CP/M-68K was released in 1982. On 5/3/2024 7:11 PM, Norman Jaffe via cctalk wrote: Not quite. CP/M is not a rename of PL/M. PL/M is a derivative of the programming language PL/I and was used in the development of CP/M - it is not an operating system. CP/M-86 was a later development of CP/M that was designed to run on 16-bit Intel processors. CP/M-68K was another branch of CP/M for use with Motorola 68K processors. From: "Murray McCullough via cctalk" To: "cctalk" Cc: "Murray McCullough" Sent: Friday, May 3, 2024 4:46:54 PM Subject: [cctalk] CP/M I came across an article that said CP/M came out in April 1974. I remember using this OS in the microcomputer world in the late 70’s; early 80’s. It came from PL/M, (Programming Language for Microcomputers) later renamed CP/M(Control Program for Microcomputers). I’m not sure what its legacy is though as far as I can recall it was wrapped up in litigation for quite some time. It was used in the 8-bit world but not sure what it's role was in the early PC world! Happy computing, Murray 🙂
[cctalk] Re: Double Density 3.5" Floppy Disks
On 4/30/2024 4:07 PM, Wayne S via cctalk wrote:
What kind of floppies did Hp recommend to use with this drive?
Sent from my iPhone
On Apr 30, 2024, at 13:55, Fred Cisin via cctalk wrote:
On Tue, 30 Apr 2024, John Herron via cctalk wrote:
Yup, that's all I used to do. Some scotch tape over the floppy disk hole to
make the system see it as DD. If it didn't automatically format as 720, you
could specify size or sector count with format.com in dos.
Somemedia sensors are optical; use opaque taps.
I did hear folks say it wasn't always reliable (similar to 5.25 disks being
formated on a high density drive) but I never saw any problems in my
limited use.
3.5" are 600 VS 750 oersted;
5.25" are 300 vs 600 Oersted;
a low density 5.25 formatted as "high density" won't do well;
a high density 5.25" (1.2M) formatted as low density ("360K") sill self erase VERY soon, sometimes
before you can even get it over to another machine. We had a college purchasing agent in bed with
"Roytype", who kept giving us "1.2M" floppies ofr out TRS80s; they self erased very soon.
--
Grumpy Ol' fredci...@xenosoft.com
[cctalk] Re: BASIC
Microsoft loves to take languages developed by others and transmogrify them into the "Microsoft Universe". Quick Basic, Visual Java, Visual Basic, Visual C# (barely resembles C) and the worst offender of all Visual C++ .NET. Your post reminded me that Postscript is an actual programming language as well. On 5/2/2024 11:24 AM, Chuck Guzis via cctalk wrote: I'll add a postscript with my reaction upon seeing my first Microsoft Visual BASIC program code: "What the hell is this? It's not BASIC!" --Chuck
[cctalk] Re: What to take to a vintage computer show
I had a similar experience at VCF Midwest where the line voltage was as low as 90 VAC. My area was without power for about 2 hours during setup. On 5/2/2024 11:01 AM, Douglas Taylor via cctalk wrote: I learned at VCF East this year that I should have brought an UPS to make sure that my vintage equipment had good, clean AC power. My PDP11 kept on resetting during the show. Doug On 5/1/2024 9:53 PM, Brad H via cctalk wrote: Just reaching out to anyone who has exhibited at a vintage computing festival before. After years of only being able to watch others attend the ones that happen in the US, we are finally getting one in BC here. Super excited. I was invited both to speak and to exhibit, and they even got me two tables which is awesome. Like, how do you prepare for these things? What things that you didn't think of going into your first show do you wish you had? I have a pretty eclectic collection, and some really rare stuff (like my Mark-8s) that I'd love to bring but am hesitant about due to the risks of transportation damage and theft (from the car mostly, not the convention itself). Just trying to decide what to bring and how focused to be in terms of theme. Brad
[cctalk] Re: BASIC
Fred, It's not a big deal. I was exposed to the DTSS as a 7th grader because I was going to a boarding school near by in 1972. The school I was at had a PDP-8/L and I became an early adopter computer geek.🙂 On 5/1/2024 6:05 PM, Fred Cisin via cctalk wrote: On Wed, 1 May 2024, Mike Katz wrote: I'm sorry but the original BASIC as run on the Dartmouth Time Sharing System was compiled. I wasn't around Dartmouth, and my first experiences with BASIC were all interpreted. I had run a trivial program in it on a Silent 700 connected through a phone line, long before I got my first personal computer (TRS80). Thank you for the details of the history. When Microsoft introduced "BASCOM" (their BASIC compiler), my first uses of it were primarily to make my source code less easily accessible to would-be infringers. :-) -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: APL (Was: BASIC
I remember replacing the character generator eprom (the type with the window for UV erasing) on an old ATI EGA video board so that I could have the APL character set. On 5/1/2024 7:14 PM, Fred Cisin via cctalk wrote: APL was incredible. I was amazed. I was immediately able to do a few simple things that were useful for my boss and myself, and writing simple programs within hours. Its matrix arithmetic was awesome. APL typeball on a selectric terminal at GSFC, . . . Some of the keys were re-labeled, but there was a chart on the wall of which keyboard characters were which APL symbols. On Wed, 1 May 2024, Chuck Guzis via cctalk wrote: It was indeed. It was also one of the first languages implemented on a microprocessor-based personal computer system. (MCM-70). To me, APL is logical--strict right-to-left precedence; simple array and matrix operations. I've long wondered if we introduced students to APL as a first language, what our applications code would look like today. My friend Bruce, called it "That Iverson Language". It's interesting to note that the Iverson book was published in 1962, but an implementation (under 7090 IBSYS) didn't come about until 1965, although preliminary implementation as PAT had been done on a 1620 (!) in 1963. The extended character set was an important obstacle to its acceptance. Besides keyboard (masking tape) and output (APL typeball, special character generator, or having to substitute combinations of character), many people were unwilling to even try something with a different character set. -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: BASIC
I'm sorry but the original BASIC as run on the Dartmouth Time Sharing
System was compiled.
On 5/1/2024 5:26 PM, Fred Cisin via cctalk wrote:
On Wed, 1 May 2024, Murray McCullough via cctalk wrote:
Nostalgia keeps pressing ahead: It was 60 yrs. ago that BASIC came into
existence. I remember very well writing in Apple Basic and GW Basic
later
on. As a non-compiled OS, an interpreted OS, it was just the right
tool for
a microcomputer with limited memory. I recall fondly taking code from
popular magazines and getting them to run. It was thrilling indeed!
Happy computing,
Murray 🙂
BTW, BASIC ("Beginners All-purpose Symbolic Instruction Code") was
developed at Dartmouth college by Kurtz and Kemeny. More than 30
years later was the first time (or so they claimed) that they EVER got
around to trying ANY of the BASICs based on their original language.
They were APALLED!
They came out with "TRUE BASIC", to counter the various "street BASICs.
picky details, . . . BASIC was a non-compiled interpreted LANGUAGE,
not an OS ("Operating System"), at least in the examples you mention.
(also TRS80 and some models of Commodore)
However, to be fair, there did exist something called "Microsoft
Stand-Alone BASIC", used in the Coco, some models of NEC 8801 (and 9801?)
That was a Microsoft BASIC that had rudimentary disk operations built
in, to serve the needed functions of an OS.
The disk directory structure of Microsoft Stand-Alone BASIC, with
directory entris pointing into a linked list allocation table,was the
inspiration for Tim Paterson to use as the directory structure for
PC-DOS/MS-DOS/86-DOS/QDOS ("Quick and Dirty Operating System" (a
placeholder to use during hardware development while waiting for the
overdue CP/M-86)) .
More details to research, . . .
GWBASIC was a version of BASICA of the 5150/PC, but run from MS-DOS,
and not requiring the ROMS. That was so that OEMs of MS-DOS could
supply BASIC closely matching that of the PC. Some even renamed
GWBASIC into "BASICA", topreserve compatability for batch files that
called BASIC.
Q: What did "GWBASIC" stand for?
at the time, some Microsoft people said that it stood for "Gee Whiz
BASIC". But more recently, Microsoft denies any memory of what it
was, and billg speculated that it stood for "Greg Whitten BASIC".
--
Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: BASIC
The Beginners All-purpose Symbolic Instruction Code (BASIC) Developed by John G. Kemeny and Thomas E. Kurtz at Dartmouth College in 1963. This ran on the Dartmouth Time Sharing System (DTSS) which was an early time sharing system running on Honeywell and GE Main Frames with Datanet systems running the terminal interfaces. This system was intended to be an online code/run/debug cycle system rather than a batch processing system like most Cobol and Fortran compilers were. BASIC was actually their third language attempt to simplify the syntax of languages like Fortran and Algol. There are literally 100's of dialects of BASIC, both as compilers (as was the original) and interpreters and even pseudo compilers. Like many of us older members of this thread, some form of BASIC was our "computer milk language" (our first computer language). Some early microcomputers even wrote their operating systems in some form of BASIC. I learned basic in September of 1972 on a 4K PDP-8/L running EduSystem 10 Basic with time also spent at the Kiewit Computation Center at Dartmouth (as a 12 year old) running Dartmouth Basic. Let's hear your earliest introduction to BASIC. On 5/1/2024 5:03 PM, Murray McCullough via cctalk wrote: Nostalgia keeps pressing ahead: It was 60 yrs. ago that BASIC came into existence. I remember very well writing in Apple Basic and GW Basic later on. As a non-compiled OS, an interpreted OS, it was just the right tool for a microcomputer with limited memory. I recall fondly taking code from popular magazines and getting them to run. It was thrilling indeed! Happy computing, Murray 🙂
[cctalk] Re: Double Density 3.5" Floppy Disks
I tried formatting multiple times (standard operating procedure). I don't have a PC with a 3.5" floppy attached any more but I did try bulk erasing the disk first. On 4/30/2024 5:21 PM, Just Kant via cctalk wrote: Format it more then once. That may afford additional stability. Try formatting it in a pc. Then switch over to the HP.
[cctalk] Re: Double Density 3.5" Floppy Disks
I am not familiar with a 9114 only the 9114A and 9114B.
On 4/30/2024 6:15 PM, Mike Stein wrote:
Just wondering: I see 9114 and 9114A being used interchangeably (mine
are 9114s); are they the same or actually different drives?
m
On Tue, Apr 30, 2024 at 5:39 PM Mike Katz via cctalk
wrote:
Thank you for your help.
That is the command I am using on the 41 to try and format the disk.
With a directory size of 60.
On 4/30/2024 4:22 PM, Wayne S via cctalk wrote:
> Also this article refers to a set of commands for this drive.
The NEWM command formats a new disk.
> Link is
https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=78
>
>
> Sent from my iPhone
>
> On Apr 30, 2024, at 14:07, Wayne S wrote:
>
> What kind of floppies did Hp recommend to use with this drive?
>
> Sent from my iPhone
>
> On Apr 30, 2024, at 13:55, Fred Cisin via cctalk
wrote:
>
> On Tue, 30 Apr 2024, John Herron via cctalk wrote:
> Yup, that's all I used to do. Some scotch tape over the floppy
disk hole to
> make the system see it as DD. If it didn't automatically format
as 720, you
> could specify size or sector count with format.com
<http://format.com> in dos.
>
> Somemedia sensors are optical; use opaque taps.
>
> I did hear folks say it wasn't always reliable (similar to 5.25
disks being
> formated on a high density drive) but I never saw any problems in my
> limited use.
>
> 3.5" are 600 VS 750 oersted;
> 5.25" are 300 vs 600 Oersted;
> a low density 5.25 formatted as "high density" won't do well;
> a high density 5.25" (1.2M) formatted as low density ("360K")
sill self erase VERY soon, sometimes before you can even get it
over to another machine. We had a college purchasing agent in bed
with "Roytype", who kept giving us "1.2M" floppies ofr out TRS80s;
they self erased very soon.
>
> --
> Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: Double Density 3.5" Floppy Disks
Yes but hopefully less than $45 for 10 disks. On 4/30/2024 5:29 PM, Wayne S via cctalk wrote: Are these the disks you need? https://www.ebay.com/itm/303254321218?var=0&mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338590836&toolid=10044&customid=bb4f007d293e125433cd664c59b413a4 Sent from my iPhone On Apr 30, 2024, at 15:22, Just Kant via cctalk wrote: Format it more then once. That may afford additional stability. Try formatting it in a pc. Then switch over to the HP.
[cctalk] Re: Double Density 3.5" Floppy Disks
Thank you. My goal is not to use HD floppies on a drive not designed for them. I saw some on ebay and amazon but I thought I would try here to see if anybody had some they don't need. I would help keep them out of the trash. Thank you again. On 4/30/2024 6:15 PM, Wayne S wrote: If it’s any help, i second the reformat completely a disk in a old pc. I had some issues many years ago where disks formatted on an ibm pc didn’t work correctly on a non- ibm pc. Reformatting and doing the error checking by reading and writing all sections fixed it. A quick format didn’t. There are lotsa 720k diskette’s available for sale… prices vary. Even Amazon has them! Sent from my iPhone On Apr 30, 2024, at 15:39, Mike Katz wrote: Thank you. I didn't see any new procedures that I have already tried. I do not have a problem with the drive or with trying to format a HD disk with the HP-41 and therefore I was looking for a few DSDD disks instead of DSHD disks. On 4/30/2024 5:13 PM, Wayne S wrote: There is also these 2 procedures to try…. From https://literature.hpcalc.org/community/hp9114a-ms-en.pdf TheHP9114Ausesdouble-sideddiscs.Dataiswrittenonboth sides of the disc. Thus the normal formatting procedure is double- sided formatting. Single-sided formatting is allowed for transferring data from older systems. See the next section for single-sided formatting. Before a flexible disc can be used for the first time, it must be formatted. Formatting establishes the directory and volume label as wellasverifyingthatthemediaisnotdamaged.Shownnextare two ways to format discs. Insert a blank disc into the disc drive. From the P.A.M. display, pressing the “File Manager” (f2) softkey gets you to a “Format” softkey. Press the key labeled ““Format” (f5) and answer the next questions. “Enter the disc to format”. The first disc drive is assigned the letter C. Type C: and press return. “Enter a volume label (optional).” The volume label is the name you want to call the disc. This can be up to 11 characters. For example, let’s call this disc “First”. Type First and press Return. The information is displayed on the first two lines below the cursor.PresstheStartFormatkey(f1)ifthesetwolinesarecorrect. “Formatting Disc. Please wait.” appears on the display. Formatting a disc takes about 1 1/2 minutes. The interleave used with this formattingmethodis8,theoptimalforHP Portable/9114A operation. After formatting is complete, pressing the “’Exit Format” (f8) softkey returns you to the main File Manager display. To exit File Manager press the “Exit File Manager” softkey. This ends the format procedure. ThesecondmethodofformattingdiscsistousetheMSDOS Format command. From the initial P.A.M. display, tabbing over to the area called “DOS Commands” and pressing “Return” allows you to use the DOS command called Format. The interleave used inthiscommand is8whichisoptimalforyourHP Portable/9114A system. Type FORMAT C: and press Return. “Press any key to begin formatting C:” is displayed. Press any key on the keyboard. Formatting takes about 1 1/2 minutes. After formatting is complete there is another prompt on the display ““Volume label (11 characters, Enter for none)?. *“Press “Return”if you don’t want a label or enter the name and press “Return” if you want to label the volume. When completed “Format another (Y/N)?” appears on the display. Typing “N” gets you back to entering MS DOS commands. Type “EXIT” to return to P.A.M. Formatting Single-sided TheHPPortable/9114Asystemcanformatdouble-sideddiscsina single-sided format. This is allowed for data compatability with other 3 1/2-inch disc systems. There is a utility called “Format.Com”ontheutilitydiscsuppliedwithyourHP Portable computer.Youmustloadthe“Format.Com”utilityintoyourHP Portable. Use the following sequence. PlacetheUtilitydiscintoyourHP9114A. TabovertotheDOS Command blockandpressStartApplic. From theMS DOS command displaytype: COPY C: FORMAT.COM A: and press Return This loads the utility and allows you to use the extra parameters explainedinthefollowingFORMATcommand. TheMS DOS command thatallowsthiscompatibilitywithits parameters isshown next. Format C:/W -Single-sided /X -Double-sided with 256 byte sectors /Y -Double-sided with 512 byte sectors /Z -Double-sided with 1024 byte Sent from my iPhone On Apr 30, 2024, at 14:39, Mike Katz wrote: Thank you for your help. That is the command I am using on the 41 to try and format the disk. With a directory size of 60. On 4/30/2024 4:22 PM, Wayne S via cctalk wrote: Also this article refers to a set of commands for this drive. The NEWM command formats a new disk. Link is https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=78 Sent from my iPhone On Apr 30, 2024, at 14:07, Wayne S wrote: What kind of floppies did Hp recommend to use with this drive? Sent from my iPhone On Apr 30, 2024, at 13:55, Fred Cisin via cctalk wrote: On Tue, 30 Apr 2024, John Herron via cct
[cctalk] Re: Double Density 3.5" Floppy Disks
Thank you. I didn't see any new procedures that I have already tried.
I do not have a problem with the drive or with trying to format a HD
disk with the HP-41 and therefore I was looking for a few DSDD disks
instead of DSHD disks.
On 4/30/2024 5:13 PM, Wayne S wrote:
There is also these 2 procedures to try…. From
https://literature.hpcalc.org/community/hp9114a-ms-en.pdf
TheHP9114Ausesdouble-sideddiscs.Dataiswrittenonboth sides of the disc.
Thus the normal formatting procedure is double- sided formatting.
Single-sided formatting is allowed for transferring data from older
systems. See the next section for single-sided formatting.
Before a flexible disc can be used for the first time, it must be
formatted. Formatting establishes the directory and volume label as
wellasverifyingthatthemediaisnotdamaged.Shownnextare two ways to
format discs. Insert a blank disc into the disc drive.
From the P.A.M. display, pressing the “File Manager” (f2) softkey gets
you to a “Format” softkey. Press the key labeled ““Format” (f5) and
answer the next questions.
“Enter the disc to format”. The first disc drive is assigned the
letter C. Type C: and press return.
“Enter a volume label (optional).” The volume label is the name you
want to call the disc. This can be up to 11 characters. For example,
let’s call this disc “First”. Type First and press Return.
The information is displayed on the first two lines below the
cursor.PresstheStartFormatkey(f1)ifthesetwolinesarecorrect.
“Formatting Disc. Please wait.” appears on the display. Formatting a
disc takes about 1 1/2 minutes. The interleave used with this
formattingmethodis8,theoptimalforHP Portable/9114A operation.
After formatting is complete, pressing the “’Exit Format” (f8) softkey
returns you to the main File Manager display. To exit File Manager
press the “Exit File Manager” softkey. This ends the format procedure.
ThesecondmethodofformattingdiscsistousetheMSDOS Format command. From
the initial P.A.M. display, tabbing over to the area called “DOS
Commands” and pressing “Return” allows you to use the DOS command
called Format. The interleave used inthiscommand
is8whichisoptimalforyourHP Portable/9114A system.
Type FORMAT C: and press Return.
“Press any key to begin formatting C:” is displayed. Press any key on
the keyboard. Formatting takes about 1 1/2 minutes.
After formatting is complete there is another prompt on the display
““Volume label (11 characters, Enter for none)?. *“Press “Return”if
you don’t want a label or enter the name and press “Return” if you
want to label the volume.
When completed “Format another (Y/N)?” appears on the display. Typing
“N” gets you back to entering MS DOS commands. Type “EXIT” to return
to P.A.M.
Formatting Single-sided
TheHPPortable/9114Asystemcanformatdouble-sideddiscsina single-sided
format. This is allowed for data compatability with other 3 1/2-inch
disc systems. There is a utility called
“Format.Com”ontheutilitydiscsuppliedwithyourHP Portable
computer.Youmustloadthe“Format.Com”utilityintoyourHP Portable. Use the
following sequence.
PlacetheUtilitydiscintoyourHP9114A. TabovertotheDOS Command
blockandpressStartApplic.
From theMS DOS command displaytype: COPY C: FORMAT.COM A: and press
Return
This loads the utility and allows you to use the extra parameters
explainedinthefollowingFORMATcommand.
TheMS DOS command thatallowsthiscompatibilitywithits parameters
isshown next.
Format C:/W -Single-sided
/X -Double-sided with 256 byte sectors
/Y -Double-sided with 512 byte sectors /Z -Double-sided with 1024 byte
Sent from my iPhone
On Apr 30, 2024, at 14:39, Mike Katz wrote:
Thank you for your help.
That is the command I am using on the 41 to try and format the disk.
With a directory size of 60.
On 4/30/2024 4:22 PM, Wayne S via cctalk wrote:
Also this article refers to a set of commands for this drive. The
NEWM command formats a new disk.
Link is
https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=78
Sent from my iPhone
On Apr 30, 2024, at 14:07, Wayne S wrote:
What kind of floppies did Hp recommend to use with this drive?
Sent from my iPhone
On Apr 30, 2024, at 13:55, Fred Cisin via cctalk
wrote:
On Tue, 30 Apr 2024, John Herron via cctalk wrote:
Yup, that's all I used to do. Some scotch tape over the floppy disk
hole to
make the system see it as DD. If it didn't automatically format as
720, you
could specify size or sector count with format.com in dos.
Somemedia sensors are optical; use opaque taps.
I did hear folks say it wasn't always reliable (similar to 5.25
disks being
formated on a high density drive) but I never saw any problems in my
limited use.
3.5" are 600 VS 750 oersted;
5.25" are 300 vs 600 Oersted;
a low density 5.25 formatted as "high density" won't do well;
a high density 5.25" (1.2M) formatted as low density ("360K") sill
self erase VERY soon, sometimes before you can even get it over to
another machine. We had a colle
[cctalk] Re: Double Density 3.5" Floppy Disks
Thank you for your help.
That is the command I am using on the 41 to try and format the disk.
With a directory size of 60.
On 4/30/2024 4:22 PM, Wayne S via cctalk wrote:
Also this article refers to a set of commands for this drive. The NEWM command
formats a new disk.
Link is https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=78
Sent from my iPhone
On Apr 30, 2024, at 14:07, Wayne S wrote:
What kind of floppies did Hp recommend to use with this drive?
Sent from my iPhone
On Apr 30, 2024, at 13:55, Fred Cisin via cctalk wrote:
On Tue, 30 Apr 2024, John Herron via cctalk wrote:
Yup, that's all I used to do. Some scotch tape over the floppy disk hole to
make the system see it as DD. If it didn't automatically format as 720, you
could specify size or sector count with format.com in dos.
Somemedia sensors are optical; use opaque taps.
I did hear folks say it wasn't always reliable (similar to 5.25 disks being
formated on a high density drive) but I never saw any problems in my
limited use.
3.5" are 600 VS 750 oersted;
5.25" are 300 vs 600 Oersted;
a low density 5.25 formatted as "high density" won't do well;
a high density 5.25" (1.2M) formatted as low density ("360K") sill self erase VERY soon, sometimes
before you can even get it over to another machine. We had a college purchasing agent in bed with
"Roytype", who kept giving us "1.2M" floppies ofr out TRS80s; they self erased very soon.
--
Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: Double Density 3.5" Floppy Disks
Thank you for your help. This drive is not a normal drive. Please see my other answers as to why this is the case. On 4/30/2024 3:49 PM, Fred Cisin via cctalk wrote: A 720K 3.5" is about 600 Oersted; a 1.4M 3.5" is about 720-750 Oersted. You can format a 1.4M as 720K, and often, maybe even usually, get away with it; it will be just like a poor quality 720K. On drives with a media sensor, you can cover the hole during formatting. On Tue, 30 Apr 2024, Anders Nelson via cctalk wrote: Having grown up with 1.44MB 3.5" floppies, I have a question: is it possible to use a 1.44MB disk and just format it as a 720K disk? =] -- Anders Nelson www.andersknelson.com On Tue, Apr 30, 2024 at 1:00 PM Mike Katz via cctalk wrote: Does anybody have any extra 720K (double sided, double density) 3.5" Floppy Disks that could use a good home? If so, please email me directly at bit...@12bitsbest.com. Thank you, Mike
[cctalk] Re: Double Density 3.5" Floppy Disks
Thank you for trying to help. My situation is unusual at best and I'm apologize for the extra bandwidth my question is causing. I am formatting the floppies in an HP-9114A battery operated floppy drive connected to an HP-41 calculator over the HP_IL serial interface. The HP9114A drive uses a modified Sony 3.5" floppy drive running at 600 RPM instead of the normal 300 RPM. This is an extremely unusual configuration that is different from any PC/MAC/Commodore/Amiga situation. I have been working with floppies since 1980. I have written floppy low level formatters (WD1771 & WD1791 controllers). I currently use a greaseweasel connected to a pair of 8" drives to create and copy floppies for the RX02 on my PDP-8. I fully understand about density and number of tracks, sectors per track, tracks per inch, fm/mfm/gcr encoding, etc. I'm sure if I tried enough 1.44MB floppies I would find a few that might work on the HP9114A drive. However, that was not my question. I am looking for a dozen or two Double Sided, Double Density 720K (formatted capacity) disks to use with this drive. I appreciate all of the suggestions and help but let's keep the bandwidth down and take any floppy compatibility discussions off of the group. Than you again everyone for offering to help, Mike On 4/30/2024 2:41 PM, Wayne S wrote: What errors are you seeing? Sent from my iPhone On Apr 30, 2024, at 12:29, Mike Katz via cctalk wrote: I have tried bulk erasing 1.44 MB disks and they still won't format in the HP9114A battery operated HP-IL Floppy Disk drive. On 4/30/2024 12:20 PM, Joshua Rice via cctalk wrote: On 30/04/2024 18:08, Anders Nelson via cctalk wrote: Having grown up with 1.44MB 3.5" floppies, I have a question: is it possible to use a 1.44MB disk and just format it as a 720K disk? I think it's entirely possible. I'd definitely format them in a 720kb drive though to be extra safe. Though original 720KB disks written/formatted in 1.44MB drives seem perfectly cromulent from my experience. However don't quote me on it, The only double density drives i have are super early Sony ones built in 1982 and they get pampered with NOS 720kb media (with the sliders sellotaped open because no auto opening shutters on my drives!) Josh Rice
[cctalk] Re: Double Density 3.5" Floppy Disks
I have tried bulk erasing 1.44 MB disks and they still won't format in the HP9114A battery operated HP-IL Floppy Disk drive. On 4/30/2024 12:20 PM, Joshua Rice via cctalk wrote: On 30/04/2024 18:08, Anders Nelson via cctalk wrote: Having grown up with 1.44MB 3.5" floppies, I have a question: is it possible to use a 1.44MB disk and just format it as a 720K disk? I think it's entirely possible. I'd definitely format them in a 720kb drive though to be extra safe. Though original 720KB disks written/formatted in 1.44MB drives seem perfectly cromulent from my experience. However don't quote me on it, The only double density drives i have are super early Sony ones built in 1982 and they get pampered with NOS 720kb media (with the sliders sellotaped open because no auto opening shutters on my drives!) Josh Rice
[cctalk] Re: Double Density 3.5" Floppy Disks
Bulk Erasing is the first thing I tried On 4/30/2024 12:48 PM, John Robertson via cctalk wrote: On 2024/04/30 10:08 a.m., Anders Nelson via cctalk wrote: Having grown up with 1.44MB 3.5" floppies, I have a question: is it possible to use a 1.44MB disk and just format it as a 720K disk? =] -- Anders Nelson www.andersknelson.com As I recall you had to bulk erase the old diskette and then you could format it as 720 - covering the 1.44 hole of course. Not bulk erasing (the side of a Weller soldering gun works just fine) led to erratic results. We all have Weller guns for fixing computers, eh? John :-#)# On Tue, Apr 30, 2024 at 1:00 PM Mike Katz via cctalk wrote: Does anybody have any extra 720K (double sided, double density) 3.5" Floppy Disks that could use a good home? If so, please email me directly at bit...@12bitsbest.com. Thank you, Mike
[cctalk] Re: Double Density 3.5" Floppy Disks
No, this is for use in an HJP9114A HP-IL Floppy Drive. On 4/30/2024 12:08 PM, Anders Nelson via cctalk wrote: Having grown up with 1.44MB 3.5" floppies, I have a question: is it possible to use a 1.44MB disk and just format it as a 720K disk? =] -- Anders Nelson www.andersknelson.com On Tue, Apr 30, 2024 at 1:00 PM Mike Katz via cctalk wrote: Does anybody have any extra 720K (double sided, double density) 3.5" Floppy Disks that could use a good home? If so, please email me directly at bit...@12bitsbest.com. Thank you, Mike
[cctalk] Double Density 3.5" Floppy Disks
Does anybody have any extra 720K (double sided, double density) 3.5" Floppy Disks that could use a good home? If so, please email me directly at bit...@12bitsbest.com. Thank you, Mike
[cctalk] Re: Z80 vs other microprocessors of the time.
I think Ohio Scientific made a computer called the 3B or something like that that had a 6502, a Z-80 and a 6800 in it. If my memory serves. On 4/23/2024 7:00 PM, Fred Cisin via cctalk wrote: On Tue, 23 Apr 2024, Van Snyder via cctalk wrote: I shared an office with a lady who got a computer from Ohio Scientific that had both a Z80 and a 6502. It also had two 5/25" floppy drives. She also got a tee-shirt that said "I have two floppies." Except she didn't. aside from her floppies, . . . a significant portion (I remember at one time, somebody at Apple said 20%) of Apple users had the Microsoft SoftCard Z80, or imitations thereof. At least one of the Apple imitations had both 6502 and Z80. -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: Z80 vs other microprocessors of the time.
Well, it was beyond the PC's and Sparc stations we had access to at the time. On 4/22/2024 3:28 PM, Christian Kennedy via cctalk wrote: On 4/22/24 13:12, Fred Cisin via cctalk wrote: On Mon, 22 Apr 2024, Mike Katz via cctalk wrote: [Big snip -- hopefully I managed to get attribution right, apologies in advance if I borked it] When I was working for a 6800 C compiler company we could simulate all 68000 CPUs before the 68020. The 68020 with it's pipelining and branch prediction made it impossible to do cycle accurate timing. Again, not impossible, but very likely not feasable. Having done cycle accurate simulation of a pipelined superscalar processor, I can assure you it's possible, particularly with hardware assist a la Quickturn . It's also a lot like watching paint dry.
[cctalk] Re: Z80 vs other microprocessors of the time.
True, if 1 cycle per second or minute is an acceptable emulation speed🙂. For that kind of emulation to work the emulator needs to be fed the same tasks in the same order and for the same core. This is even more true when the CPU is waiting on internal or external resources. If you can emulate all of the cores, all 3 (or more) levels of cache, all possible branch prediction, all possible out of order execution and all possible external influences then yes you can emulation anything. But that would be like using one of today's petaflop hyper computers to emulate an ARM 9 running at the speed of a Z-80 or even slower. On 4/22/2024 2:57 PM, Paul Koning wrote: On Apr 22, 2024, at 3:45 PM, Mike Katz wrote: Cycle accurate emulation becomes impossible in the following circumstances: • Branch prediction and pipelining can cause out of order execution and the execution path become data dependent. ... I disagree. Clearly a logic model will do cycle accurate simulation. So an abstraction of that which still preserves the details of out of order execution, data dependency, etc., will also be cycle accurate. It certainly is true that modern high performance processors with all those complexities are hard to simulate, but not impossible. paul
[cctalk] Re: Z80 vs other microprocessors of the time.
Compilers do that with what is called loop rotation optimization. On 4/22/2024 3:59 PM, Chuck Guzis via cctalk wrote: On 4/22/24 13:53, Paul Koning via cctalk wrote: In COMPASS: MORESA1 A1+B2 (B2 = 2) SA2 A2+B2 BX6 X1 LX7 X2 SB3 B3-2 SA6 A6+B2 SA7 A7+B2 PL b3,MORE My recollection is that putting the stores at the top of the loop and the loads at the bottom managed to save a few cycles. Of course, you have to prime the loop... --Chuck
[cctalk] Re: Z80 vs other microprocessors of the time.
Again, not impossible, but very likely not feasable. Well not possible with the hardware available at the time. If one cycle per minute or less is acceptable then I guess it was possible. That is why we used in circuit emulators to do cycle accurate counting on more complex machines. This machines were clunky and unreliable but they worked for the most part. On 4/22/2024 3:12 PM, Fred Cisin via cctalk wrote: On Mon, 22 Apr 2024, Mike Katz via cctalk wrote: Cycle accurate emulation becomes impossible in the following circumstances: * Branch prediction and pipelining can cause out of order execution and the execution path become data dependent. * Cache memory. It can be very difficult to predict a cache flush or cache miss or cache look aside buffer hit * Memory management can inject wait states and cause other cycle counting issues * Peripherals can inject unpredictable wait states * Multi-core processors because you don't necessarily know what core is doing what and possibly one core waiting on another core. * DMA can cause some CPUs to pause because the bus is busy doing DMA transfers (not all processors have this as an issue). * Some CPUs shut down clocks and peripherals if they are not used and they take time to re-start. * Any code that waits for some kind of external input. Ridiculously impractical, but not impossible. All of those things could be calculated, and worked around. Admittedly, we might not have a machine fast enough to do so. Whereas, emulation that doesn't need to do those can be done with systems not extremely faster than the one being emulated. When I was working for a 6800 C compiler company we could simulate all 68000 CPUs before the 68020. The 68020 with it's pipelining and branch prediction made it impossible to do cycle accurate timing. Again, not impossible, but very likely not feasable. -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: Z80 vs other microprocessors of the time.
Once CPUs became faster than memory the faster the memory the faster the CPU could run. That is where CACHE came in. Expensive small high speed ram chips would be able to feed the CPU faster except in case of a cache miss and then the cache had to reload from slow memory. That is why multiple cache buffers were implemented so one could be filling (predicatively) while another buffer was being used. Some early CPU's were run slowly enough so that the memory could keep up and some had built in hardware handshaking. For example the 68000 had a signal called DTACK which was used by the memory/peripheral to say that it had latched the data on the bus (on writes) or that the data is stable on the bus (on reads). Or used quadrature clocks (like the 6809 [the 6809E ran a 2 phase non-quadrature clock]) that gave memory more than one cycle time to respond. On 4/22/2024 3:02 PM, Wayne S via cctalk wrote: I read somewhere that the cable lengths were expressly engineered to provide that signals arrived to chips at nearly the same time so as to reduce chip “wait” times and provide more speed. So that begs a question. Older chips like the Z80 and 8080 lines required other support chips that added latency to a system waiting for the support chips to “settle”. Does that imply that newer microprocessors that have support on the chip are just generally faster because of that? Sent from my iPhone On Apr 22, 2024, at 12:54, Chuck Guzis via cctalk wrote: On 4/22/24 12:31, ben via cctalk wrote: Classic cpu designs like the PDP-1, might be better called RISC. Back then you matched the cpu word length to data you were using. 40 bits made a lot of sense for real computing, even if you had no RAM memory at the time, just drum. I'd call the CDC 6600 a classic RISC design, at least as far as the CPU went. Classes were given to programming staff on timing code precisely; I spent many happy hours trying to squeeze the last few cycles out of a loop (where the biggest bang for the buck was possible). I think bitsavers (I haven't looked) has a document or two on how to time code for that thing. --Chuck
[cctalk] Re: Z80 vs other microprocessors of the time.
Cycle accurate emulation becomes impossible in the following circumstances: * Branch prediction and pipelining can cause out of order execution and the execution path become data dependent. * Cache memory. It can be very difficult to predict a cache flush or cache miss or cache look aside buffer hit * Memory management can inject wait states and cause other cycle counting issues * Peripherals can inject unpredictable wait states * Multi-core processors because you don't necessarily know what core is doing what and possibly one core waiting on another core. * DMA can cause some CPUs to pause because the bus is busy doing DMA transfers (not all processors have this as an issue). * Some CPUs shut down clocks and peripherals if they are not used and they take time to re-start. * Any code that waits for some kind of external input. When I was working for a 6800 C compiler company we could simulate all 68000 CPUs before the 68020. The 68020 with it's pipelining and branch prediction made it impossible to do cycle accurate timing. On 4/22/2024 1:46 PM, Paul Koning via cctalk wrote: On Apr 22, 2024, at 2:34 PM, Chuck Guzis via cctalk wrote: On 4/22/24 11:09, Bill Gunshannon via cctalk wrote: Following along this line of thought but also in regards all our other small CPUs Would it not be possible to use something like a Blue Pill to make a small board (small enough to actually fit in the CPU socket) that emulated these old CPUs? Definitely enough horse power just wondered if there was enough room for the microcode. Blue pills are so yesterday! There are far more small-footprint MCUs out there. More RAM than any Z80 ever had as well as lots of flash for the code as well as pipelined 32-bit execution at eye-watering (relative to the Z80) speeds. Could it emulate a Z80? I don't see any insurmountable obstacles to that. Could it be cycle- and timing- accurate? That's a harder one to predict, but probably. Probably not. Cycle accurate simulation is very hard. It's only rarely been done for any CPU, and if done it tends to be incredibly slow. I remember once using a MIPS cycle-accurate simulator (for the SB-1, the core inside the SB-1250, later called BCM-12500). It was needed because the L2 cache flush code could not be debugged any other way, but it was very slow indeed. Almost as bad as running the CPU logic model in a Verilog or VHDL simulator. I don't remember the numbers but it probably was only a few thousand instructions per second. Then again, for the notion of a drop-in replacement for the original chip, you don't need a cycle accurate simulator, just one with compatible pin signalling. That's not nearly so hard -- though still harder than a SIMH style ISA simulation. paul
[cctalk] Re: Last Buy notification for Z80 (Z84C00 Product line)
Even the 6809 could push up to 8 registers (up to 10 bytes) at once on one of two stacks in a single two byte instruction. On 4/21/2024 11:27 AM, Chuck Guzis via cctalk wrote: On 4/21/24 07:45, Mike Katz via cctalk wrote: One of the biggest features of the Z-80, the extra register set, was rarely used in open source software in order to maintain compatibility with the 8080. My understanding of the extra (partial) set of registers on the Z80 was that they were intended for a quick context switch particularly when processing interrupts--another interesting feature of the Z80 that was rarely used. So, for ordinary user code, they were a no-go. The alternative on the Intel MPUs was to push each 16-bit register pair at the entry of the interrupt routine and then pop them at the end; a relatively slow process, made worse by the requirements for extra stack space. Of course, the extra register feature went largely unused, as relatively few consumer- or hobbyist-level products actually made much use of the interrupt feature, much less, the 256-level vectored interrupt facility. The 8086 continued this trend of requiring explicit saves; some of the NEC V-series chips (e.g. V25), however, did implement extra register sets (8 total, IIRC) for fast context switches. --Chuck
[cctalk] Re: Last Buy notification for Z80 (Z84C00 Product line)
Well my PDP-8 was built in 1974 and is still running (with careful maintenance). My PiDP-8/I has been up and running continuously with a Raspberry PI 3B running it for about 5 years now. My PiDP-11 has been up and running with a PI-4B for more than 4 years continuously. Though I agree with your comment that the PDP-8 was built to last (just ignore the disintegrated foam used between the motherboard and the case or on the case top) I have PCs that are more than 10 years old that are still running. As for the RP2040 being cheap crap, I beg to differ with you. It is a solid chip, produced in 10s of millions at least. And, I would bet, a better quality chip than your Z-80, if due only to improved IC manufacturing technologies. Just because it's old doesn't make it good. I worked on a 32KHz 4 Bit CPU (about 20 years ago) where the development hardware was very unstable and the tool chain not a whole lot better. Early Microsoft and Lattice C compilers for the PC were buggy as hell. If you want I can list a few bugs from each of them in another thread. One of the biggest features of the Z-80, the extra register set, was rarely used in open source software in order to maintain compatibility with the 8080. Some of the early Z-80 CP/M tools did not work because they were derived from 8080 tools. After time the tools got better. That is the case with any piece of software. If it doesn't become obsolete and if maintained it will get better over time. On 4/21/2024 1:09 AM, ben via cctalk wrote: On 2024-04-20 8:33 p.m., Mike Katz via cctalk wrote: For anything more sophisticated than your coffee pot the RP2040 from Raspberry Pie is a fantastic little chip, dual core 133 MHz Cortex M0+ with 8 PIO engines, 264K of RAM, ADC, UART, SPI, I2C all for under a dollar. I designed a fully functional RP2040 with 16 Mb flash for under $2.00. In large enough quantities that's encroaching on 8 bit PIC territory at over 1000 times the memory and CPU power. I am wishing for a Quality Product, cheap crap is not always better. USB comes to mind. 256Kb ram is only 32K 64 bit words. Cache memory never works. My $5 internet toaster, just exploded after 3 days. So what? Just buy the new model that works with windows 12. Download a buggy new tool chain. The Z80 tools worked. The PDP8 was built to last. 50+ years and going strong. NOT the crappy PI PDP-8 or PDP-10. I give it 2 years max. Now a PI style computer with compact FLASH x 2, NO USB and 2 MEG ram , real serial and printer ports that will work in a noisy industrial setting, would be quite usefull. I'd pay even $3 for it. :)
[cctalk] Re: Last Buy notification for Z80 (Z84C00 Product line)
For anything more sophisticated than your coffee pot the RP2040 from Raspberry Pie is a fantastic little chip, dual core 133 MHz Cortex M0+ with 8 PIO engines, 264K of RAM, ADC, UART, SPI, I2C all for under a dollar. I designed a fully functional RP2040 with 16 Mb flash for under $2.00. In large enough quantities that's encroaching on 8 bit PIC territory at over 1000 times the memory and CPU power. On 4/20/2024 6:30 PM, Doc Shipley via cctalk wrote: On 4/20/24 13:16, Wayne S via cctalk wrote: Who still uses the Z80 line for new projects? Wouldn’t it be easier and cheaper to just use an Arduino or Raspberry Pi? I dissected a dead coffee maker last week that has a current-design 8051 clone running the control board. Well-known instruction sets and "Nobody cares if I clone this" make powerful arguments Doc
[cctalk] Re: Drum memory on pdp11's? Wikipedia thinks so....
There was drum storage for the early PDP-8 the "Straight 8", PDP-9 and PDP-10. Each drum stored 32,768 words. Up to 8 of them could be connected for a total storage of 262,144 words of storage. IBM made a 5BM drum storage unit that was the side of a small refrigerator: The RAMAC's disk storage unit, the IBM 350, weighed over a ton, had to be moved around with forklifts, and was delivered via large cargo airplanes. It stored approximately 5MB of data: *five million 8-bit characters on fifty 24-inch-diameter disks*, a form of drum memory. On 4/15/2024 11:06 AM, Douglas Taylor via cctalk wrote: At the VFC East just a few days ago a young man came up to me, I had a PDP11/53 on display, and showed me pictures of his 11/45 and PDP-8 that he had just acquired and needed to learn about. It was impressive, he said the 11/45 was missing the memory boards. If he shows up here on the list please help him. To me, it look like he had stumbled into a Unicorn. Doug On 4/13/2024 5:26 PM, Christopher Zach via cctalk wrote: Was reading the Wikipedia article on Drum memories: https://en.wikipedia.org/wiki/Drum_memory#External_links And came across this tidbit. As late as 1980, PDP-11/45 machines using magnetic core main memory and drums for swapping were still in use at many of the original UNIX sites. Any thoughts on what they are talking about? I could see running the RS03/RS04 on a 11/45 with the dual Unibus configured so the RS03's talk to memory directly instead of the Unibus, but that's not quite the same as true drum memory. Closest thing I remember was the DF32 on a pdp8 which could be addressed by word as opposed to track/sector. Thoughts? C
[cctalk] Re: IBM 360
I want to thank you all for this IBM 360 conversation. It makes me feel young🙂. My first computer was a PDP-8/L with 4K of core memory and a Teletype ASR-33. That was 1972 (I was 12). On 4/10/2024 4:23 PM, Paul Koning via cctalk wrote: On Apr 10, 2024, at 5:01 PM, Van Snyder via cctalk wrote: ... I think the 360/67 replaced "Halt and Catch Fire" with "Rewind and Break Tape." I always wondered if that wasn't a standard property of IBM tape drives of that era. The ones I remember from our 360/44 had capstans that turned continuously, one to each side of the head. The tape was shoved against the capstan to start tape motion, and against a rubber brake block to stop it. That was wild enough, but the other crazy aspect is that the vacuum columns were arranged so the oxide was facing outward, i.e., rubbing against the side walls of the vacuum column. I never did wear out a tape, but then again, I never used a tape more than a half dozen times on that system. paul
[cctalk] Re: oscilloscopes
For some reason the mailing list deleted the link to the photo, I'm sorry. On 4/3/2024 11:01 AM, Mike Katz via cctalk wrote: I still have a TEK 475A (with the DMM4 on top) and a TEK 11043A mainframe scope. The 475A is rock solid and is one of the best analog triggering scopes ever made. The 11403A goes all the way up to 3GHz but, tbh, is was a difficult to use touch screen scope. I still use both of them occasionally. I had a Sony Tektronix Battery Operated 10 or 20 MHz scope ( I can't remember which) that was lent out never to be seen again. The nicest thing about it was that the two channels were completely electrically isolated from each other. My go to scopes now are a couple of PicoScope USB scopes with logic analyzers and arbitrary function generators. Here are the two TEK scopes. The 475A is showing both a sine and a square wave at 1 MHz (chopped). The 11403A is showing a 1GHz sine wave and 7 other unconnected traces just to show that is can display 8 traces at once. The three plugins on the 11403A are, 4 trace 3000MHz/trace, 2 trace 1GHz/trace and 2 trace 50MHz Current Probe Amplifier. On 4/1/2024 5:56 PM, Fred Cisin via cctalk wrote: On Mon, 1 Apr 2024, Just Kant via cctalk wrote: I have more then I need. All the working ones are HP w/color crts, and as far as older, verifiably vintage tools (right down to the 680x0 processor in either) I have to admit I favor them as a brand. Call we an oddball, weird egg, badges I wear with pride. But who could resist the allure of the newer ultra portable, even handheld units (some with bandwidth or sampling rates to 50mhz). I'm a big cheapo. But there's no real reason to agonize over a 65 - 200$ or thereabouts acquisition. It's a bit tiring to wade through the piles of availability. I favor a desktop unit, larger screen (but not always, careful). But most of those need wall current I think? The convenience of a handheld battery powered unit obviously has it's benefits. I will always love and dote upon my color crt based HPs. But the damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d over, hit the paved floor, shook the house. And still works! Built to withstand an atomic bombardment. I had a Tektronix 512, and an NLS215 (battery powered portable) from a company that switched over to making Kaypros. I gave it away at one of the first VCFs. I guess that the vintage ones are no longer adequate. -- Grumpy Ol' Fred
[cctalk] Re: oscilloscopes
I still have a TEK 475A (with the DMM4 on top) and a TEK 11043A mainframe scope. The 475A is rock solid and is one of the best analog triggering scopes ever made. The 11403A goes all the way up to 3GHz but, tbh, is was a difficult to use touch screen scope. I still use both of them occasionally. I had a Sony Tektronix Battery Operated 10 or 20 MHz scope ( I can't remember which) that was lent out never to be seen again. The nicest thing about it was that the two channels were completely electrically isolated from each other. My go to scopes now are a couple of PicoScope USB scopes with logic analyzers and arbitrary function generators. Here are the two TEK scopes. The 475A is showing both a sine and a square wave at 1 MHz (chopped). The 11403A is showing a 1GHz sine wave and 7 other unconnected traces just to show that is can display 8 traces at once. The three plugins on the 11403A are, 4 trace 300MHz/trace, 2 trace 1GHz/trace and 2 trace 50MHz Current Probe Amplifier. https://drive.google.com/file/d/10lFayScEaebLSAKRyEhUmIC_MoONMkcu/view?usp=sharing On 4/1/2024 5:56 PM, Fred Cisin via cctalk wrote: On Mon, 1 Apr 2024, Just Kant via cctalk wrote: I have more then I need. All the working ones are HP w/color crts, and as far as older, verifiably vintage tools (right down to the 680x0 processor in either) I have to admit I favor them as a brand. Call we an oddball, weird egg, badges I wear with pride. But who could resist the allure of the newer ultra portable, even handheld units (some with bandwidth or sampling rates to 50mhz). I'm a big cheapo. But there's no real reason to agonize over a 65 - 200$ or thereabouts acquisition. It's a bit tiring to wade through the piles of availability. I favor a desktop unit, larger screen (but not always, careful). But most of those need wall current I think? The convenience of a handheld battery powered unit obviously has it's benefits. I will always love and dote upon my color crt based HPs. But the damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d over, hit the paved floor, shook the house. And still works! Built to withstand an atomic bombardment. I had a Tektronix 512, and an NLS215 (battery powered portable) from a company that switched over to making Kaypros. I gave it away at one of the first VCFs. I guess that the vintage ones are no longer adequate. -- Grumpy Ol' Fred
[cctalk] Re: oscilloscopes
I still have a TEK 475A (with the DMM4 on top) and a TEK 11043A mainframe scope. The 475A is rock solid and is one of the best analog triggering scopes ever made. The 11403A goes all the way up to 3GHz but, tbh, is was a difficult to use touch screen scope. I still use both of them occasionally. I had a Sony Tektronix Battery Operated 10 or 20 MHz scope ( I can't remember which) that was lent out never to be seen again. The nicest thing about it was that the two channels were completely electrically isolated from each other. My go to scopes now are a couple of PicoScope USB scopes with logic analyzers and arbitrary function generators. Here are the two TEK scopes. The 475A is showing both a sine and a square wave at 1 MHz (chopped). The 11403A is showing a 1GHz sine wave and 7 other unconnected traces just to show that is can display 8 traces at once. The three plugins on the 11403A are, 4 trace 3000MHz/trace, 2 trace 1GHz/trace and 2 trace 50MHz Current Probe Amplifier. On 4/1/2024 5:56 PM, Fred Cisin via cctalk wrote: On Mon, 1 Apr 2024, Just Kant via cctalk wrote: I have more then I need. All the working ones are HP w/color crts, and as far as older, verifiably vintage tools (right down to the 680x0 processor in either) I have to admit I favor them as a brand. Call we an oddball, weird egg, badges I wear with pride. But who could resist the allure of the newer ultra portable, even handheld units (some with bandwidth or sampling rates to 50mhz). I'm a big cheapo. But there's no real reason to agonize over a 65 - 200$ or thereabouts acquisition. It's a bit tiring to wade through the piles of availability. I favor a desktop unit, larger screen (but not always, careful). But most of those need wall current I think? The convenience of a handheld battery powered unit obviously has it's benefits. I will always love and dote upon my color crt based HPs. But the damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d over, hit the paved floor, shook the house. And still works! Built to withstand an atomic bombardment. I had a Tektronix 512, and an NLS215 (battery powered portable) from a company that switched over to making Kaypros. I gave it away at one of the first VCFs. I guess that the vintage ones are no longer adequate. -- Grumpy Ol' Fred
[cctalk] Re: oscilloscopes
I'm surprised some digital scope manufacturer hasn't implemented X-Y-Z control as an option. Driving X-Y was fairly common for certain types of signals. And many also used the Z input. Back in the day there were many companies that made X-Y or X-Y-Z displays. On 4/3/2024 10:01 AM, Guy Fedorkow via cctalk wrote: Vintage computer enthusiasts might want to keep track of where to find CRT-based analog oscilloscopes, for use as output devices. The early MIT and Lincoln Labs computers used D/A converters to steer and activate the beam on analog scopes to draw vector images. Working on Whirlwind simulation, we've been able to get this technique to work with "real" oscilloscopes, e.g., Tek 475, but we have not yet found a single DSO that has X/Y _and_ Z inputs (let alone the required phosphor fade). Myself, I have a couple scopes with backups, so I'm not in the market for another one. But others might consider the option... /guy fedorkow Date: Mon, 01 Apr 2024 22:33:38 + From: Just Kant Subject: [cctalk] oscilloscopes To: "General Discussion: On-Topic and Off-Topic Posts" Message-ID: Content-Type: text/plain; charset=utf-8 I have more then I need. All the working ones are HP w/color crts, and as far as older, verifiably vintage tools (right down to the 680x0 processor in either) I have to admit I favor them as a brand. Call we an oddball, weird egg, badges I wear with pride. But who could resist the allure of the newer ultra portable, even handheld units (some with bandwidth or sampling rates to 50mhz). I'm a big cheapo. But there's no real reason to agonize over a 65 - 200$ or thereabouts acquisition. It's a bit tiring to wade through the piles of availability. I favor a desktop unit, larger screen (but not always, careful). But most of those need wall current I think? The convenience of a handheld battery powered unit obviously has it's benefits. I will always love and dote upon my color crt based HPs. But the damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d over, hit the paved floor, shook the house. And still works! Built to withstand an atomic bombardment.
[cctalk] Re: oscilloscopes
I still have a TEK 475A (with the DMM4 on top) and a TEK 11043A mainframe scope. The 475A is rock solid and is one of the best analog triggering scopes ever made. The 11403A goes all the way up to 3GHz but, tbh, is was a difficult to use touch screen scope. I still use both of them occasionally. I had a Sony Tektronix Battery Operated 10 or 20 MHz scope ( I can't remember which) that was lent out never to be seen again. The nicest thing about it was that the two channels were completely electrically isolated from each other. My go to scopes now are a couple of PicoScope USB scopes with logic analyzers and arbitrary function generators. Here are the two TEK scopes. The 475A is showing both a sine and a square wave at 1 MHz (chopped). The 11403A is showing a 1GHz sine wave and 7 other unconnected traces just to show that is can display 8 traces at once. The three plugins on the 11403A are, 4 trace 3000MHz/trace, 2 trace 1GHz/trace and 2 trace 50MHz Current Probe Amplifier. On 4/1/2024 5:56 PM, Fred Cisin via cctalk wrote: On Mon, 1 Apr 2024, Just Kant via cctalk wrote: I have more then I need. All the working ones are HP w/color crts, and as far as older, verifiably vintage tools (right down to the 680x0 processor in either) I have to admit I favor them as a brand. Call we an oddball, weird egg, badges I wear with pride. But who could resist the allure of the newer ultra portable, even handheld units (some with bandwidth or sampling rates to 50mhz). I'm a big cheapo. But there's no real reason to agonize over a 65 - 200$ or thereabouts acquisition. It's a bit tiring to wade through the piles of availability. I favor a desktop unit, larger screen (but not always, careful). But most of those need wall current I think? The convenience of a handheld battery powered unit obviously has it's benefits. I will always love and dote upon my color crt based HPs. But the damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d over, hit the paved floor, shook the house. And still works! Built to withstand an atomic bombardment. I had a Tektronix 512, and an NLS215 (battery powered portable) from a company that switched over to making Kaypros. I gave it away at one of the first VCFs. I guess that the vintage ones are no longer adequate. -- Grumpy Ol' Fred
[cctalk] Re: Cleanup time again
Considering how high some prices are on eBay. I would rather something go to a good home at a lower price than help drive the prices up on ePay. On 3/21/2024 4:01 PM, Sellam Abraham via cctalk wrote: On Thu, Mar 21, 2024 at 12:33 PM CAREY SCHUG via cctalk < cctalk@classiccmp.org> wrote: --does anybody want to comment on whether ebay prices are less, similar, or greater than at live VCFs? I have not made the effort to collect history. It depends, usually less. Sometimes the same or more. Sellam
[cctalk] Re: 5 1/4" and 3.5" disk duplication machines
If I were to build a diskette copier today I would us some kind of magnetic flux reader/writer (like the greaseweazle). That way it is format agnostic. It can copy almost any disk that can be read. I have a script for my greaseweazle that will copy any 8" diskette (mine is setup for 8" RX02 diskettes). Granted, it copies by saving the image to disk and then writing it back out. This allows the use of either 1 single disk system or the ability to make multiple copies without having to re-read the source diskette. On 3/10/2024 1:01 PM, John Herron via cctalk wrote: If referring to commercial systems, I imagine that and discussion on copyright techniques might be interesting to a hardcore crowd. If just archiving, I also think that would be useful to the public. I only saw cd/dvd based systems and harddisk duplicators. Newer stuff though, not what I would consider vintage. On Sat, Mar 9, 2024, 3:55 PM Bill Degnan via cctalk wrote: Does anyone have interest in vintage diskette duplication / duplication machines? Would this make for an interesting VCF exhibit? Does/did anyone use these commercially? Bill
[cctalk] Re: vt220 firmware source?
you may already know about these but here are a few 8051 Simulators: https://www.electronicshub.org/8051-simulators/ And thoughts on using MAME to emulate terminals: https://zork.net/~st/jottings/Real-VT102-emulation-with-MAME.html Good luck. I have a fully functional VT-330+ and a fully functional VT-220 if i can help at all. On 2/5/2024 10:23 AM, Paul Flo Williams via cctalk wrote: On Sun, 04 Feb 2024 16:26:57 -0700 Richard via cctalk wrote: In article you write: I'm about to dive in to commenting the disassembly listings, but figured I'd ping here to see if anybody might have done this already in case I wouldn't have to start from scratch? Give IDA Pro or Ghidra a crack at it to help you make sense of the raw disassembly. I made pretty good progress on VT100 ROMs before Paul Williams put up a completely reverse engineered commented listing. Well, in case it helps, I'll explicitly disclaim any intention of disassembling the VT220 :-) After the VT100, I did make a start on the VT102/131 combination but it seemed too samey to hold my interest. More than 20 years ago, I started on the VT320, as my personal favourite, but I didn't understand how to tackle emulation at the time, the 8051 emulator I wrote had flaws, and I spent a long time on getting the emulated video timing correct enough to even pass self test! If only the VT320 had had a technical reference as comprehensive as that published for the VT100. I will return to it at some point, probably using some else's 8051 core, as Peter Sichel (last head of DEC's terminals group) bet me that I wouldn't be able to do it. At the moment, I'm tackling another full commentary, but it may well have an even smaller audience than that for the VT100; I'm 83% through gutting the arcade game Star Force. I've even fixed two æsthetic bugs in the game, 40 years too late for anyone to care. At least this is Z80 assembler, and tinkering with that has always made me *very* happy. Paul.
[cctalk] Re: Qume 842 8" Disk Drive Question
I haven't worked on 8" drives since the early 80's with th exception of the RX02 drives on my PDP-8. And DEC worked their own "magic" on those drives :) Thanks for the help. On 1/31/2024 3:59 PM, Chuck Guzis via cctalk wrote: On 1/31/24 13:03, Mike Katz via cctalk wrote: Michael, Thank you, that was what I was planning as my next step. I haven't checked to see if the service manual has a full schematic. The main purpose of my message on here was to see if I was missing something obvious like an option trace cut or something like that that I missed when I checked the manual. Thanks again, Mike - There is indeed a schematic in the 842 service manual PDF page 87 is what you're looking for. Since the LEDs are always powered, you need only be concerned with the output of the phototransistor. DMM is fine; no scope necessary. An opto going bad is not completely unknown on these drives. (I have a couple of the 842s--good drives, otherwise) Diskette drives really are non-intelligent devices... --Chuck
[cctalk] Re: Qume 842 8" Disk Drive Question
I believe the pull ups are all on inputs from the external controller and not for outputs from the drive itself. Looking at the schematic the Index output (J1-P20) does not go through the pull up resistors. Thanks again for your help. On 1/31/2024 3:59 PM, Chuck Guzis via cctalk wrote: On 1/31/24 13:03, Mike Katz via cctalk wrote: Michael, Thank you, that was what I was planning as my next step. I haven't checked to see if the service manual has a full schematic. The main purpose of my message on here was to see if I was missing something obvious like an option trace cut or something like that that I missed when I checked the manual. Thanks again, Mike - There is indeed a schematic in the 842 service manual PDF page 87 is what you're looking for. Since the LEDs are always powered, you need only be concerned with the output of the phototransistor. DMM is fine; no scope necessary. An opto going bad is not completely unknown on these drives. (I have a couple of the 842s--good drives, otherwise) Diskette drives really are non-intelligent devices... --Chuck
[cctalk] Re: Qume 842 8" Disk Drive Question
That is one of the tests recommended in the service manual. It's on my list of things to check. Thank you... On 1/31/2024 2:17 PM, Chuck Guzis via cctalk wrote: On 1/31/24 11:12, Mike Katz via cctalk wrote: I have not yet tried installing terminating resistors... That might help. It's also possible that the LED/phototransistor for the SS index position is faulty. The two LEDs (SS and DS) are connected in series, so you know that at least one isn't open. Grab your DMM and check the voltage levels on pins A6 and A7 on connector J2. They should change as the beam is broken in each with a piece of tinfoil or something else opaque. --Chuck
[cctalk] Re: Qume 842 8" Disk Drive Question
Michael, Thank you, that was what I was planning as my next step. I haven't checked to see if the service manual has a full schematic. The main purpose of my message on here was to see if I was missing something obvious like an option trace cut or something like that that I missed when I checked the manual. Thanks again, Mike On 1/31/2024 2:29 PM, Michael Thompson wrote: Connect an oscilloscope to the output of the single-sided sensor and see if it works. If so, trace the signal through the logic and see if it gets to the I/O connector that goes to the greaseweazel. On Wed, Jan 31, 2024 at 2:38 PM Mike Katz via cctalk wrote: I have recently acquired a Qume Model 842 double sided 8" disk drive. I have reset all of the settings to factory default and hooked it up to my greastweazle. The drive works perfectly for double sided disks (using the appropriate index hole). However, the greaseweasel reports no index pulse when I put a single sided diskette in the drive. I have attempted to clean out the sensor for single sided diskettes to on avail. Does any one have any ideas? The grease weasel works perfectly when I connect SA-800 drives. I have not yet tried installing terminating resistors in the Qume. Thank you in advance for your help, Mike
[cctalk] Qume 842 8" Disk Drive Question
I have recently acquired a Qume Model 842 double sided 8" disk drive. I have reset all of the settings to factory default and hooked it up to my greastweazle. The drive works perfectly for double sided disks (using the appropriate index hole). However, the greaseweasel reports no index pulse when I put a single sided diskette in the drive. I have attempted to clean out the sensor for single sided diskettes to on avail. Does any one have any ideas? The grease weasel works perfectly when I connect SA-800 drives. I have not yet tried installing terminating resistors in the Qume. Thank you in advance for your help, Mike On 1/31/2024 12:56 PM, Martin Bishop via cctalk wrote: Ah, PPC VME cards, add VXworks, funky coprocessors, COTS IO and you have definitely got something best avoided : details would involve libations. The conduction cooled chassis are OK and worth repurposing. Contrariwise the VME bus is best avoided, whether classic 32b VME or the 64 bit revision. However, the connectors for VME 64x backplanes and the form factor have merit, but that is to depart from the past. Martin -Original Message- From: Wouter de Waal via cctalk [mailto:cctalk@classiccmp.org] Sent: 31 January 2024 18:34 To: cctalk@classiccmp.org Cc: Wouter de Waal Subject: [cctalk] Re: Vmebus Anyone have a VMEbus system they use at least occasionally? If so, what make/model/config? I still use a couple of PPC VME boards (DY4 / Curtiss Wright 182/183/184, both Conduction-Cooled and Air-Cooled) to test the tail end of hardware that we are still shipping (by now EOL and basically NOS). But it's work, I don't find them interesting. If someone here has the warm fuzzies for PPC VME, we can talk :-) W
[cctalk] Re: PDP-8/E front panels
I have tired to print the paddle handles both SLA and FDM and none match the quality and strength of injected molded paddles. Unless you print an entire set (light and dark colors) it is nearly impossible to match the colors also. Even if you were to find the perfect filament or resin color, the variability between batches makes accurate reproduction nearly impossible. On 11/17/2023 10:15 AM, Tom Hunter via cctalk wrote: I had some toggles printed for me professionally, but they are inferior to the originals and the colours don't match. If anyone has spare DEC LAB-8/e switches please let me know. Thanks Tom On Fri, Nov 17, 2023, 10:14 PM Bill Gunshannon via cctalk < cctalk@classiccmp.org> wrote: On 11/17/2023 8:52 AM, Tom Hunter via cctalk wrote: Hi Bob, I can't help with your search for 8/e front panels, but you mentioned "green switch boards". I have a nicely restored DEC LAB-8/e with green switch toggles. Do you have spare green switch toggles? I would love to have one dark green and one light green toggle. I don't need the actual switch, but would be happy to take the toggles with switch. Please let me know if you can help. Have you ever considered making your own? https://www.thingiverse.com/thing:360853 bill
[cctalk] Re: What happened to the PDP-8 on ebay?
The original listing price was $25,000 and was reduced to $18,000 when there we no bids at the original price. On 10/5/2023 2:34 PM, Sellam Abraham via cctalk wrote: On Tue, Oct 3, 2023, 9:18 PM jim stephens via cctalk wrote: On 10/3/23 21:23, Bill Degnan via cctalk wrote: There was a PDP-8 (rack straight 8 with asr33) that was on ebay that disappeared..anyone know if it was sold? I can't find it, maybe the seller pulled the auction to sell privately. Bill I trolled thru VCF forum and I think this is the one you recall. It's the last straight 8 I saw listed. https://www.ebay.com/itm/145314563635 I also off your topic have observed a German listing and British listing for Olivetti Programma 101s for 40,000 pounds and 60,000 euro, in the same fantasy range as this listing which is for $18,000. This listing shows currently terminated September 20 due to an error in the listing. No relist by this vendor. He also did something on Sept 2 with is. Thanks jim Realistically, $18,000 is not a bad price at all for a complete PDP-8. The only downside is the broken off corner of the front panel glass. Sellam
[cctalk] Teletypes for sale - redux with pics on google drive and contact info.
Hey folks. I need to re-home a bunch of cool old Teletype Corporation machines. Working condition unknown, and also have some spare parts. I am not out to make a mint, so make offer! They seem mostly complete, in varying condition. Some are nicer than others. They all worked when stored (years ago) The following need to find new homes: TT Model 28 ASR (3 of these) TT Model 28 KSR (2 of these) TT Model 28 RO (2 of these) Extra Model 28 Parts TT Model 28 Floor Standing Paper Punch TT Model 32 Baudot TT Model 35 KSR (heavy duty version of the ASR-33) TT Model 35 ASR (Floor stand heavy duty, 2 of these, one Telex) TT Model 40 Dataspeed Teletype manuals and documentation for each model Tell your friends! Delivery is possible. I can assist with loading. Message me for details. Located in the Midwest (Missouri) Pictures: https://drive.google.com/drive/folders/1iWKntZTwws1Qdk6JPEh4f7BjbP0of62t?usp=sharing Contact: Mat at Mobile Techinical Services, (217) 690-9239 (mobiletechs...@gmail.com)
[cctalk] Teletypes for sale
Hey folks. I need to re-home a bunch of cool old Teletype Corporation machines. Working condition unknown, and also have some spare parts. I am not out to make a mint, so make offer! They seem mostly complete, in varying condition. Some are nicer than others. They all worked when stored (years ago) The following need to find new homes: TT Model 28 ASR (3 of these) TT Model 28 KSR (2 of these) TT Model 28 RO (2 of these) Extra Model 28 Parts TT Model 28 Floor Standing Paper Punch TT Model 32 Baudot TT Model 35 KSR (heavy duty version of the ASR-33) TT Model 35 ASR (Floor stand heavy duty, 2 of these, one Telex) TT Model 40 Dataspeed Teletype manuals and documentation for each model Tell your friends! Delivery is possible. I can assist with loading. Message me for details. Located in the Midwest (Missouri) https://www.facebook.com/groups/vintagecomputerclub/permalink/7307144265985543/
[cctalk] Re: Good C to FPGA/PLA compiler
Martin, Thank you for all of your suggestions. I am a software guy who has dabbled in hardware since I built my first Heathkit in 1972. I have designed simple 6809 single boards in my past professional life but the Omnibus is several orders of magnitude more complicated than a 6809. Just reading the Single Cycle Data Break documentation in the Omnibus spec is enough to give me a headache. I think in C much better than I think in logic gates. I can write parallel C to describe parallel circuits. The last time I programmed any programmable logic it was FPGA's of the 10L8/16V10 variety. Sometimes the data is on the memory bus, sometimes it is on the data bus, depending on whether you are reading or writing to memory, for example. There is no bus multplexing between address and data or data and memory busses. Here is the basic definition of the Omnibus: Memory Address: 15 Signals Memory Data: 12 Signals Memory Direction: 1 Signal Data Bus: 12 Signals I/O Control Signals: 10 Signals DMA Control Signals: 8 Signals Timing Signals: 9 Signals CPU State: 6 Signals Memory Timing: 5 Signals Misc Signals: 18 Signals (Mostly used by the front panel) One of my goals here is to use thru hole parts and sockets so the average person can assemble it. I realize this may be impossible bit I'm trying. I have a good surface mount contract manufacturer close to my home that I have a business relationship will so I can go to full surface mount if I have to but that will increase the cost of the boards. On 9/22/2023 6:53 PM, Martin Bishop via cctalk wrote: Mike An M0 will require an FPGA below it to interact with the OmniBus A BeagleBone, using the PRUs - which are ~microcoded, would be in with more of a chance Industrial grade SoCs / FPGAs should have no difficulty Martin -Original Message----- From: Mike Katz via cctalk [mailto:cctalk@classiccmp.org] Sent: 23 September 2023 00:27 To: General Discussion: On-Topic and Off-Topic Posts Cc: Mike Katz Subject: [cctalk] Re: Good C to FPGA/PLA compiler I plan on controlling the gate array with an RP2040 dual core cortex M0 running at 133 MHz and 8 PIO processors. However, the Data Break (DMA) timings on the Omnibus are in the 100nS range. The bus runs 6 different timing signals plus manipulating all of the other signals to implement Data Break. I just don't think a micro would be fast enough. That same holds for the break point. In order to be able to respond to address, data, r/w and count for 4 breakpoints in the <1uS window to stop the CPU before the start of the next cycle would stress most embedded micros (sub $10 micros anyway). The PDP-8/E main clocks are derived from a 20MHz crystal (That's a 50nS minimum timing). Quoting the DEC Omnibus Standard Document Memory, Address and Data must be settled within 50nS minimum and no more than 250nS depending on what is going on on the bus. There is a boot strap board that emulates the front panel with an Arduino and an I/O expander. But to implement Data Break requires much more tight timing. This bus was designed to handle core memory which requires a write after read because the read is destructive. On 9/22/2023 5:52 PM, Chuck Guzis via cctalk wrote: Stupid question, I know, but someone has to ask it. Is there some overwhelming reason that the FPGA and associated logic couldn't be subsumed into an inexpensive 32-bit MCU running at, oh, 200 MHz? I can't believe that a PDP8 is all that fast... --Chuck
[cctalk] Re: Good C to FPGA/PLA compiler
I have no plans to emulate the CPU. This is intended to be a board to help debug programs and possibly some hardware issues. On 9/22/2023 6:06 PM, Martin Bishop via cctalk wrote: Chuck, Your point is wholly valid, although the core will run more at 1 GHz than 200 MHz. The UniBone http://retrocmp.com/projects/unibone is a UniBus board capable of monitoring the unibus and of emulating CPU / rotating rust / memory / ... With the bulk of the logic in c on an Arm Processor. Jay Jaeger has just elaborated the UniBone's essentials. Martin -Original Message- From: Chuck Guzis via cctalk [mailto:cctalk@classiccmp.org] Sent: 22 September 2023 23:53 To: ben via cctalk Cc: Chuck Guzis Subject: [cctalk] Re: Good C to FPGA/PLA compiler Stupid question, I know, but someone has to ask it. Is there some overwhelming reason that the FPGA and associated logic couldn't be subsumed into an inexpensive 32-bit MCU running at, oh, 200 MHz? I can't believe that a PDP8 is all that fast... --Chuck
[cctalk] Re: Good C to FPGA/PLA compiler
I plan on controlling the gate array with an RP2040 dual core cortex M0 running at 133 MHz and 8 PIO processors. However, the Data Break (DMA) timings on the Omnibus are in the 100nS range. The bus runs 6 different timing signals plus manipulating all of the other signals to implement Data Break. I just don't think a micro would be fast enough. That same holds for the break point. In order to be able to respond to address, data, r/w and count for 4 breakpoints in the <1uS window to stop the CPU before the start of the next cycle would stress most embedded micros (sub $10 micros anyway). The PDP-8/E main clocks are derived from a 20MHz crystal (That's a 50nS minimum timing). Quoting the DEC Omnibus Standard Document Memory, Address and Data must be settled within 50nS minimum and no more than 250nS depending on what is going on on the bus. There is a boot strap board that emulates the front panel with an Arduino and an I/O expander. But to implement Data Break requires much more tight timing. This bus was designed to handle core memory which requires a write after read because the read is destructive. On 9/22/2023 5:52 PM, Chuck Guzis via cctalk wrote: Stupid question, I know, but someone has to ask it. Is there some overwhelming reason that the FPGA and associated logic couldn't be subsumed into an inexpensive 32-bit MCU running at, oh, 200 MHz? I can't believe that a PDP8 is all that fast... --Chuck
[cctalk] Re: Good C to FPGA/PLA compiler
My plan is to have both a serial port for connection to a PC/Terminal and an I2C output to a multi line display. Thanks for the suggestion. On 9/22/2023 4:45 PM, ben via cctalk wrote: On 2023-09-22 3:16 p.m., Mike Katz via cctalk wrote: Martin, The debug board will need to have the following functionality: 1. Read and write to/from memory when the CPU is running using one cycle data break (DEC's version of DMA for the PDP-8). Single Cycle DMA requires some interesting signaling, including putting the priority on the data bus during part of the cycle. 2. Read and write to/from memory when the CPU is halted using front panel emulation (something totally different than one cycle data break unfortunately) 3. Handle 4 breakpoints (based on address, data, R/W and count) and signal the cpu to stop. I don't know, yet, if there will be enough time in the CPU's instruction cycle to top the CPU before the fetch of the next instruction. If this cannot be done in hardware than a much more crude break point system can be done in software. 4. There are 96 active signals on the PDP-8/E's Omnibus. I expect to need most or all of them for this project. 5. The Omnibus is an open drain, active low bus where +2.7V to +4.5V is a zero and -0.5 to +0.4V is a one. I don't necessarily need a 5V tolerant gate array but what ever I use to interface to the bus will need to be. A full description of the Omnibus can be found here: https://bitsavers.org/pdf/dec/standards/EL-00157_00_A_DEC_STD_157_OMNIBUS_Specification_Aug76.pdf Coding the break point system in some kind of parallel C like language seems way easier to me than to write this in gates. I don't have a clue how to design the count registers. I need to get #'s 1 and 2 working first and then I can dive into #3. Thanks. Hexadecimal displays til311, (pulled DIS1417's) can be found on ebay for about $5 not counting shipping. This way you have easy to read hex or octal numbers.
[cctalk] Re: Good C to FPGA/PLA compiler
Martin, The debug board will need to have the following functionality: 1. Read and write to/from memory when the CPU is running using one cycle data break (DEC's version of DMA for the PDP-8). Single Cycle DMA requires some interesting signaling, including putting the priority on the data bus during part of the cycle. 2. Read and write to/from memory when the CPU is halted using front panel emulation (something totally different than one cycle data break unfortunately) 3. Handle 4 breakpoints (based on address, data, R/W and count) and signal the cpu to stop. I don't know, yet, if there will be enough time in the CPU's instruction cycle to top the CPU before the fetch of the next instruction. If this cannot be done in hardware than a much more crude break point system can be done in software. 4. There are 96 active signals on the PDP-8/E's Omnibus. I expect to need most or all of them for this project. 5. The Omnibus is an open drain, active low bus where +2.7V to +4.5V is a zero and -0.5 to +0.4V is a one. I don't necessarily need a 5V tolerant gate array but what ever I use to interface to the bus will need to be. A full description of the Omnibus can be found here: https://bitsavers.org/pdf/dec/standards/EL-00157_00_A_DEC_STD_157_OMNIBUS_Specification_Aug76.pdf Coding the break point system in some kind of parallel C like language seems way easier to me than to write this in gates. I don't have a clue how to design the count registers. I need to get #'s 1 and 2 working first and then I can dive into #3. Thanks.
[cctalk] Good C to FPGA/PLA compiler
I'm working on the design for an Omnibus (PDP-8/E) debug board and I am not very good at circuit design. I know there are programs that will compile something that looks like C into Verilog/VHDL/Abel/Etc for use on some kind of large (more than 64 pins) programmable logic device. Can any of you recommend a good C like tool for programmable logic? Thank you, Mike
[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party
Whom ever said youth is wasted on the young was telling a very serious truth. On 9/7/2023 7:12 PM, Tarek Hoteit wrote: Safe recovery! Yes, the physical human OLD sucks (not the geeky-part <- guess that keeps us more functioning) - - - - - - - - - - - - - Tarek Hoteit ta...@infocom.ai +1 360-838-3675 https://infocom.ai On Sep 7, 2023, at 5:07 PM, Mike Katz via cctalk wrote: My sympathies to both of you and wishes for a good and complete recovery. 2 years ago I had a heart attack in my dojo. 8 stents and a pacemaker later I was back on the mat in 3 weeks. It was 6 months before I was able to go full speed. Getting old sucks!!! On 9/7/2023 6:58 PM, KenUnix via cctalk wrote: Jon, Yea. It affected my left side. Loss of muscle strength. I am left handed and lost my strength but luckily can still type albeit slower. Good thing the keyboard has a backspace key. Fortunately I still get ideas but it sometimes takes awhile to write them down. -Ken On Thu, Sep 7, 2023 at 7:32 PM Jon Elson via cctalk wrote: On 9/7/23 17:18, KenUnix via cctalk wrote: Hi guys. Since I can't get out due to my stroke, be sure to post plenty of snaps of the event... Sorry to hear about that. I had a very mild stroke 2 years ago, but it has affected dexterity in my right hand. My writing is now horrible (my penmanship was never really great) and typing is more error prone than before. Jon
[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party
My sympathies to both of you and wishes for a good and complete recovery. 2 years ago I had a heart attack in my dojo. 8 stents and a pacemaker later I was back on the mat in 3 weeks. It was 6 months before I was able to go full speed. Getting old sucks!!! On 9/7/2023 6:58 PM, KenUnix via cctalk wrote: Jon, Yea. It affected my left side. Loss of muscle strength. I am left handed and lost my strength but luckily can still type albeit slower. Good thing the keyboard has a backspace key. Fortunately I still get ideas but it sometimes takes awhile to write them down. -Ken On Thu, Sep 7, 2023 at 7:32 PM Jon Elson via cctalk wrote: On 9/7/23 17:18, KenUnix via cctalk wrote: Hi guys. Since I can't get out due to my stroke, be sure to post plenty of snaps of the event... Sorry to hear about that. I had a very mild stroke 2 years ago, but it has affected dexterity in my right hand. My writing is now horrible (my penmanship was never really great) and typing is more error prone than before. Jon
[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party
With Dorothy and the Tin Woodsman as their salespeople 🤣 I think those would be micro-vaxen because they are only single user. On 9/7/2023 4:44 PM, ste...@malikoff.com steven--- via cctalk wrote: On 09/07/2023 2:36 AM AEST Mike Katz via cctalk wrote: Does VAX have nothing to do with vacuum cleaners? Here in Oz, VAX has been a popular brand of vacuum cleaner for many decades. We had one until recently. https://www.vax.com.au/ Steve
