Re: Whence 556?

[Christian Corti via cctalk]

On Sat, 2 Jun 2018, Chuck Guzis wrote:

So 200 and 800 are nice decimal multiples of 10.   But 556 doesn't fit
that pattern--it's not a "nice' number, being the product of 4 and 139
and doesn't correspond to any computer-related characteristics that I
know of. It's not metric.  So why 556 and not 400, 512 or 600?


Just a guess, but 556 kHz is 5 MHz divided by 9.

Christian

Re: Whence 556?

[Christian Corti via cctalk]

On Tue, 5 Jun 2018, Chuck Guzis wrote:

And we're talking bits/chars per inch, so I don't see the connection,
particularly on a 75 ips drive.


Ehm, yes, I was thinking too fast and too simple... it's a hot day here.

Christian

Re: VAX 4000 PSU (H7874) Schematics

[Christian Corti via cctalk]

On Thu, 7 Jun 2018, Aaron Jackson wrote:

The VAX turns on and the status LED stays on F. The DC lamp does not
illuminate on the PSU. 5V rail appears fine but there is nothing from
the 12V rail. There were some *very* dodgy looking caps which I have
replaced, and some *very* exploded MOSFETs, which I have also
replaced.


If that's all that you replaced, no wonder it still doesn't work ;-)
Usually shorted power transistors in SMPSUs also break one or more fusable 
resistors, maybe some diodes, maybe the driver IC or transistors.
So if you have anything that "exploded" in the power supply, be sure there 
is more work to be invested that replacing the obious parts.


Christian

Re: IBM junk

[Christian Corti via cctalk]

On Wed, 27 Jun 2018, Donald wrote:

The whole collection went to
Computer Museum of America in Roswell, GA
https://computermuseumofamerica.org/


Is that the museum that formerly was in San Diego?

Christian

Re: Preserved LGP-30

[Christian Corti via cctalk]

On Mon, 2 Jul 2018, "j...@cimmeri.com" wrote:
Seriously!  Liam, don't you know that handling paper with your hands 
transfers oils to it and hastens its decay?  This is why gloves are worn to 
handle old paper artifacts.


*lol*
Especially with oiled paper tape that is exposed to daylight and much 
more.


Christian

Re: MOS 6500/1 ROM archival service

[Christian Corti via cctalk]

On Tue, 3 Jul 2018, Jim Brain wrote:
But, I have pulled my hacked reader out from mothballs to read a CPU someone 
is sending, so I thought I would inquire if others have 6500/1 units that 
want read.


Hint: Seagate ST-225

Christian

Re: 8 inch floppies, decaying

[Christian Corti via cctalk]

On Wed, 11 Jul 2018, dwight wrote:
I've had the goo from the adhesive of 5.25 inch 360k disk come through 
the nice liner and make gobs on the disk. I tried several thing but 
found that isopropanol worked without removing any of the magnetic 
material ( maybe s tiny amount that was likely loose already ). I'm not 
saying it would be the same for 8 inch disk. Once working I did copy 
them to floppies without liners.


I use Screen 99 for cleaning floppies, and that has proved to be the best 
so far, giving a clean and smooth surface. There's no need to grapple with 
several different fluids. I don't even use lint-free cloths and the like, 
I use paper towels. The surface is so smooth that all the remaining dust 
can be blown away easily.


Christian

Re: 8 inch floppies, decaying

[Christian Corti via cctalk]

On Wed, 11 Jul 2018, Al Kossow wrote:

On 7/11/18 2:21 AM, Christian Corti via cctalk wrote:


I use Screen 99 for cleaning floppies


MSDS
https://store.comet.bg/download-file.php?id=16956
first ingredient listed; isopropyl alcohol


Of course, somehow you need some "magic" in the stuff ;-)
But as you might have seen, the weight in weight is 10% maximum. And when 
sprayed on the surface (only a small spot) it generates a nice solid foam. 
It hasn't dissolved the binder/oxide for now, not even on Wabash floppies 
(that in my experience aren't too horrible, some noname stuff is much 
worse).
If I'm afraid that it might dissolve the media I can always test it 
first on the inner side next to the hub hole. And I don't rub the 
media with high pressure, only gently. It is important to extract the 
floppy from its sleeve for cleaning, though.


Christian

Re: zilog system 8000

[Christian Corti via cctalk]

On Wed, 18 Jul 2018, Al Kossow wrote:

https://www.ebay.com/itm/292646012304

local pickup only

the reserve is >$1500


ROTFL
A very big and expensive door stopper without OS tapes.
But most importantly: the CPU board is missing!
The card in slot 2 appears to be an additional SIO card.

This is a model 20, quite low-end. We have a model 32 (much rarer, I 
haven't found anyone else with a model 32), but it is non-functional 
because I have no tapes. The SMD disk has too many errors to recover a 
functional system.


Christian

Re: SDL and SunOS

[Christian Corti via cctalk]

On Sat, 21 Jul 2018, carlos_muri...@ieee.org wrote:
Under SunOS 4.1.4, the last gcc version that is supported is 3.3.6, but I 
haven't been able to build it on an IPX;  it gets to the point where it


Not quite true:

# uname -a
SunOS azu 4.1.1 10 sun4 unknown unknown SunOS

# gcc -v
Reading specs from /ibm/usr/lib/gcc/sparc-sun-sunos4.1.1/3.4.6/specs
Configured with: ../gcc-3.4.6/configure --prefix=/ibm/usr 
--program-suffix=-3.4 --with-gnu-ld --with-ld=/ibm/usr/bin/ld 
--with-gnu-as --with-as=/ibm/usr/bin/as --with-cpu=v7 --disable-nls 
--with-libiconv-prefix=/ibm/usr --enable-obsolete

Thread model: single
gcc version 3.4.6

# ld --version
GNU ld 2.9.1
Copyright 1997 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License.  This program has absolutely no warranty.
  Supported emulations:
   sun4

# as --version
GNU assembler 2.9.1
Copyright 1997 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License.  This program has absolutely no warranty.
This assembler was configured for a target of `sparc-sun-sunos4.1.1'.


This is on a SUN 4/260 with 32MB RAM.

starts running gengtype and eats all memory available (I have 64MB RAM and 
have added as much as 1024 swap and it still crashes).  So, for the time


Yes, there are such issues. The solution is to cross compile it with 
distcc.


Christian

HP-2116 front panel lamps

[Christian Corti via cctalk]

Hi,

I need to replace several broken lamps from our HP-2116B front panel. The 
old/original ones are CM-345 or OL-345. This makes sense, they are rated 
6V 40mA 1 hours.


BUT:
The maintenance manual says something different and is even wrong and 
inconsistent.

HP part number is 2140-0035, description "Lamp, Incadescent, 6.3V, 0.75A"
This can't be true. 92*0.75A would be 400W alone for the front panel 
lights...
The manufacturer code is 71744 (Chicago Miniature Lamp Works), mfg part 
number 1775. That is indeed a 6.3V lamp, but 0.075A (better!). Problem: 
that is a midget _screw_ base lamp, so wrong socket and only rated for 
1000h. The panel and switches need a midget flanged base lamp. Who wrote 
that manual? Was he drunk? ;-)



Christian

RE: HP-2116 front panel lamps

[Christian Corti via cctalk]

On Wed, 25 Jul 2018, it was written

Christian, when I was restoring the HP Computer Museum's 2116A I ordered a
bunch of these 345 bulbs from 1000bulbs.com - but it seems they no longer
stock them.

I did find this listing though which looks current...
https://www.lighting-pros.com/eiko-345-t-1-3-4-midget-flanged-sx6s-case-of-1
0

They are around 0.04A current draw - not 0.75A!


Yes, the Installation and Maintenance Manual on bitsavers 
(02116-9153_2116B_Vol2_Oct70.pdf) contains several errors.
Interesting enough, my printed copy of this manual from 1968 (that is 
completely different from the 1970 one; it only has parts lists and 
schematics, the chapters for installation and maintenance are simply not 
there) is right: 2140-0035  6.3V 0.04A


In the meantime I've ordered a bunch of JKL 345 from Mouser (60 Ecent/piece)
:-)

Christian

Re: HP-2116 front panel lamps

[Christian Corti via cctalk]

On Wed, 25 Jul 2018, GerardCJAT wrote:
When I was "doing sort of " C.E. for 2116 ( 1971 _ 1981 ), we were using 
CM 380 as replacement. Even longer life !!


Good info! Don't know how I could miss this one, it is even cheaper than 
the 345. I think I wanted to stick to the same type as the ones in the 
panel.


Christian

Re: R: HP-2116 front panel lamps

[Christian Corti via cctalk]

On Wed, 25 Jul 2018, it was written

I've buy these lamps from Oshino Lamps, the original supplier for a good
price. Minimun quantity 100 pcs


Speaking of Oshino Lamps, I had a phone call yesterday with their German 
branch after I had inquired them for a distributor; I saw the OL-345 on 
their web sites so I thought I'd just ask them.
Well, it was very "interesting". First question I was asked: How on earth 
did I undig this ld type. Well, it is on their web sites, I told them.
Huh, well, it may be listed there, but they don't have them as active in 
their system. The last time they sold the OL-345 was 15 years ago. They 
"could" ask Japan if they had some in stock, but for 100 pcs I could just 
forget that.

Another question: does it have to be the exact same type? And so on...
So my conclusion is that they don't have/produce/know of the old lamp 
types.


Christian

Troubleshooting HP 2116B

[Christian Corti via cctalk]

Ok, so I've got the computer almost running now. I now need to fix both 
sense amplifier cards. One (0..4k) sometimes reads a one for bit 3 after 
the machine has warmed up. The other (4..8k) has a stuck one for bit 7.
Swapping these cards make the errors move to the other core bank 
respectively.


I have the newer cards, 02116-6298, not the older 02115-6001
The latter has CA3028A used as sense amplifiers. My card uses HP 
1820-0183 (metal can IC from RCA). I guess that it is also a CA3028A or 
maybe a CA3053. Can anyone confirm this?


Next, the manual on bitsavers (02116-9153_2116B_Vol2_Oct70, and the same 
as found on the hpmuseum site) not only contains some errors (see my other 
post about the front panel lamps). It has also some badly scanned pages 
with parts missing, notably page 5-50 (PDF page 350) lacks the right part 
of the page. Is there a better scan available? My 1968 copy does not list 
the 02116-6298.


Christian

Re: Troubleshooting HP 2116B

[Christian Corti via cctalk]

On Sat, 28 Jul 2018, GerardCJAT wrote:

Christian,
I absolutly agree with David s post.
Back in the ' '70 when I was maintaining 3 x HP 2116 B running 24/24 7/7 
FOR around 10 YEARS, the ONLY memory related problem that I got was 
traced to a faulty transistor !!


Then I have a new fault ;-)
After swapping the transistors with those for bit 16 (parity, not used in 
this machine), the fault was still there. Swapping the IC did not help.
Finally, I found it: one of the two 1.65k resistors going to the 
outputs was bad (open). These are the collector resistors for the 
differential amplifier.
So if I had found that resistor earlier the board would look a bit nicer 
than now; it is not easy at all to desolder those little 8 pin metal cans.


There was a short electrolytic on one inhibit driver card, but that was 
fixed several days ago. This fault was obvious: the PSU was shutting off 
with the card in its slot.


Now to the flakey bit in the other memory half. Perhaps the corresponding 
resistor on the other card starts to go bad?


Christian

RQDX3 formatter

[Christian Corti via cctalk]

Where do you patch the ZRQCH0 binary to use different geometries 
for non-DEC drives with a RQDX3?

As it seems it should be possible, but noone has told how to do this ;-)

Christian

Re: HP scope mailing list

[Christian Corti via cctalk]

On Sat, 18 Aug 2018, Curious Marc wrote:

On Aug 17, 2018, at 3:14 PM, Toby Thain via cctalk  
wrote:


On 2018-08-17 12:40 AM, Curious Marc via cctalk wrote:
+1 on the hp_agilent Yahoo group



Which at this very moment is MOVING to groups.io:

 https://groups.io/g/HP-Agilent-Keysight-equipment

Also highly recommended is the TekScopes list if you own/repair any Tek
gear:

 https://groups.io/g/TekScopes/topics

Ah, excellent, groups.io is so much better.


And still, I prefer NNTP :-D

Christian

Re: Some late fifties HP measurement equipment available. ( Switzerland )

[Christian Corti via cctalk]

On Mon, 3 Sep 2018, jos wrote:

HEWLETT PACKARD TIME INTERVAL UNIT 526B
HEWLETT PACKARD ELECTRONIC COUNTER 524C
HEWLETT PACKARD DIGITAL RECORDER 560A

( Possibly a second HP524(b) , unsure of this )


We have an HP 523CR, a real beauty. It has over 60 tubes! The LGP-30 has 
just twice as much.


Christian

Re: VT100's

[Christian Corti via cctalk]

On Thu, 6 Sep 2018, Paul Koning wrote:
The work of a VT100 is quite a lot more complex than that of a VT52 
(many more screen operations, and more complex control sequence 
parsing).  With the hardware technology available at the time, it was a 
pretty tough job.  Does the VT100 have a microprocessor? It may predate 
those.  In hardwired 7400 series logic, it isn't an easy job.


Yes, the V100 has an Intel 8080, the stripped-down V101 has an Intel 8085.

Christian

Re: HP 9845A Computer

[Christian Corti via cctalk]

On Tue, 11 Sep 2018, Marlene Klein wrote:

We have an HP 9845A computer (1977) in working condition.
Can we post it on your site?


That sounds illogical. How do you want to electronically post a physical 
object? ;-) And what site anyway? This is a mailing list.


Christian

Re: SPACEWAR! Switch Boxes for a PDP-12

[Christian Corti via cctalk]

On Sun, 23 Sep 2018, Michael Thompson wrote:

We modified the source

from D.E. WREGE

to use the LINC SXL instruction to read the PDP-12 GPIO signals, and
prototyped two switch boxes using recycled toggle switches. This works
great, so now we need to make better switch boxes.

[...]

We did something similar for our LAB-8/E, but much simpler. We just hooked 
up two ordinary game joysticks (digital ones like for the C64 or Amiga) to 
the parallel input interface and modified the code to also read that 
input :-)


Christian

Re: Rayethon Computer AN/FYK9 CMI Store 33

[Christian Corti via cctalk]

On Mon, 24 Sep 2018, Al Kossow wrote:

The only Raytheon I know of is Bob's 704
http://dvq.com/oldcomp/photos2/1k/704.jpg


Aw, come on, you could know it better. We also have a 704 since many 
years, including software and documentation. You have mirrored my scans 
on bitsavers ;-)


Christian

Re: Rayethon Computer AN/FYK9 CMI Store 33

[Christian Corti via cctalk]

On Mon, 24 Sep 2018, Chuck Guzis wrote:

How about some 22-bit or 13 bit architectures?


How about our Dietz MINCAL 523? 19 bit architecture, memory is 20 bits 
with parity. Microprogrammed machine, microcode within normal address 
space, mixed twos-complement and sign-magnitude arithmetic. Completely 
reverse-engineered due to lack of information :-))
8K core memory, microcode and boot loader stored in foil ROMs (similar to 
wire rope ROMs).


Christian

TK50Z (was: Rack-mount or tabletop version of DEC RX50 floppy drive?)

[Christian Corti via cctalk]

On Wed, 3 Oct 2018, Adrian Graham wrote:
Here?s a pic of my RX50 and TK50. I?ve not tried to power them up for 
years.


Speaking of TK50 and since I'm playing with them at the moment, is there 
any information on the SCSI command set for the TK50Z? My goal is to talk 
to one on a Linux system, but the TK50Z is special enough that it won't 
work as a generic SCSI tape drive, at least by default as it seems.


Christian

Digico computer

[Christian Corti via cctalk]

We recently got a Digico Micro 16V computer including a Pertec 3342 disk 
drive. It is a 16 bit minicomputer based on 74181 ALUs and a couple of 4k 
core memory modules.
Since the condition of the system is not the best (dirt, dust, some 
bent wirewrap pins), I'm looking for the usual information :-))

- technical manual, schematics
- software
I'm thankful for any information.

Christian

RE: Digico computer

[Christian Corti via cctalk]

On Fri, 5 Oct 2018, it was written

I worked with DIGICO?s in 1974.
Is it red?
Does it have a manual pull through paper tape reader?
Was it made in the UK?
I am most interested


Yes, it is red and has a small reader on the front plate. The machine 
seems to be complete (expect the disk drive that is missing the removable 
platter assembly/heads).

I can make some pictures these days.

Christian

RE: Digico computer

[Christian Corti via cctalk]

On Fri, 5 Oct 2018, it was written

http://www.vintage-icl-computers.com/icl49c

Drawings for 16V here


No, only some non-readable pictures of drawings :-(
I should ask the guy to scan them reasonably.

Christian

RE: Digico computer

[Christian Corti via cctalk]

On Sat, 6 Oct 2018, Christian Corti wrote:

I can make some pictures these days.


So, here they are: 
http://computermuseum.informatik.uni-stuttgart.de/pics/digico


Some notes from my part:
There were two systems, there is only the front panel and board set left 
from the second one. One front panel says "LOS", the other "micro 16v".
Also pictures from the Pertec drive wreck that I hope can be restored to a 
fixed platter only drive. (PCBs not shown, but I have them)
I have three memory boards in total, and the two CPU boards are different 
revisions. The one shown is MK2, the other is MK1 with a lot of green 
wires. All boards seem to be soldered by hand!


Christian

RE: Digico computer

[Christian Corti via cctalk]

On Wed, 10 Oct 2018, it was written

Did you contact the guy with the drawings?


Yes but I haven't heard back from him, yet. At least the mail hasn't 
bounced. Does anyone know the person who runs vintage-icl-computers.com ?
There is no name, address or anything there, and I wonder if the site is 
still alive.


Christian

Re: Ultrix Tape: Block Size?

[Christian Corti via cctalk]

On Tue, 16 Oct 2018, Warren Toomey wrote:

All, I received this request from Matthew who isn't subscribed to either
the TUHS or cctalk lists. He knows how to read the lists archives. Many
thanks for any help you can provide.
Cheers, Warren


See
https://ifctfvax.superglobalmegacorp.com/releases/UNIX/thirdparty/Ultrix-32/ult420vaxdist-tk50/sup/

Christian

Re: Identifying TO-3 w/HP house numbering

[Christian Corti via cctalk]

On Mon, 15 Oct 2018, Josh Dersch wrote:

Got an HP 2382A terminal I'm attempting to resurrect.  I get no video, no
heater, no high voltage.  What I believe to be the horizontal output
transistor appears to be bad, but I'm not sure if this thing contains
internal diodes that might be throwing off my testing attempts.  It's
labeled "1854-0900."  Anyone know what this actually is?  (Anyone have a
service manual for this terminal?)


It's possible that the video section is identical to that of the HP 120. 
According to Tony Duell's schematics, the HOT is a MJ10006. The HP9816, 
also similar in shape, uses a BUZ45.

The HP150 uses HP part number "1854-0948" which is also a MJ10006.

Christian

Re: TK50, was: Re: [TUHS] Ultrix Tape: Block Size?

[Christian Corti via cctalk]

On Wed, 17 Oct 2018, Clem Cole wrote:

As Paul W pointed out correctly, the TK50 and its children in the DLT*
family all used a fixed format 512 byte *blocks on the tape*.This


And that is wrong. The TK50 clearly uses variable block sizes. For 
example, have a look at a RSX11 or VMS tape:


# mtdump AQ-RAE30-01.tap
Processing input file AQ-RAE30-01.tap
Processing tape file 1
Obj 1, position 0, record 1, length = 80 (0x50)
Obj 2, position 88, record 2, length = 80 (0x50)
Obj 3, position 176, record 3, length = 80 (0x50)
Obj 4, position 264, record 4, length = 80 (0x50)
Obj 5, position 352, record 5, length = 80 (0x50)
Obj 6, position 440, end of tape file 1
Processing tape file 2
Obj 7, position 444, record 1, length = 2048 (0x800)
Obj 8, position 2500, record 2, length = 2048 (0x800)
Obj 9, position 4556, record 3, length = 2048 (0x800)
Obj 10, position 6612, end of tape file 2
Processing tape file 3
Obj 11, position 6616, record 1, length = 80 (0x50)
[...]
Processing tape file 5
Obj 21, position 7328, record 1, length = 9216 (0x2400)
[...]
Processing tape file 8
Obj 363, position 3061188, record 1, length = 2048 (0x800)
[...]
Processing tape file 62
Obj 2370, position 19735716, record 1, length = 32256 (0x7E00)
[...]


Christian

Re: does a reverse-engineering EDA tool exist?

[Christian Corti via cctalk]

On Thu, 25 Oct 2018, Guy Dunphy wrote:
Keep the objective in mind. What you want to end up with is a schematic, 
that is laid out in a way that aids comprehension of how the circuit 
works. Typically this means overall left to right functional or power 
flow, with separate functional blocks visually separate, visual emphasis 
where appropriate, and so on. Something like the original designers 
drew, if they were any good.



When you have only a PCB and want to reverse engineer the schematic, the 
tasks are:

[...]

This is actually the way how I reverse-engineered the MINCAL 523. Identify 
the address and data busses, registers, latches, functional sections (e.g. 
ALU, interrupt related, I/O, ...) and put that all together. And yes, it 
involves a lot of paper and pencil work, and that is faster and much more 
intuitive than doing it with the computer.

To create the schematics I use gschem from the gEDA suite.

Currently, I have started to reverse-engineer the Digico computer. I have 
only looked at the CPU board so far, but that leads to a dead-end as I am 
not able to unambiguously identify the address and data busses. So I have 
to continue with the front panel, start with the display/keypad where you 
can select the individual registers for entry/display and go back to the 
front panel connector back to the CPU board. There, I hope to find the 
instruction register and continue with the instruction decoder section.


Christian

Re: PDP, Data General & more (TV show Maniac)

[Christian Corti via cctalk]

On Wed, 31 Oct 2018, Stéphane Tsacas wrote:

TV show Maniac (available on netflix), S1E2 @28.48, at least a PDP 11/40,
11/05 or 04, RX01, PDP-8, and 2 Data General Eclipse, DEC doc binders, and
maybe an IBM front panel and more.


What is a PDP-8/1 XA ?

Christian

Re: Informix for SCO XENIX

[Christian Corti via cctalk]

On Tue, 13 Oct 2020, Sean Ellis wrote:

Just wanted to let you all know that I've found a copy of Informix
3.11 for SCO XENIX on the Lisa 2... anyone interested?


Interesting, yesterday I got a copy of Informix 2.0 for SINIX (a Siemens 
XENIX derivate) for the PC-X.


Christian

Re: Informix for SCO XENIX

[Christian Corti via cctalk]

On Thu, 15 Oct 2020, it was written

Can I get a copy of that? I have a PC-X ;)


It can be found on our FTP server:
ftp://computermuseum.informatik.uni-stuttgart.de/siemens/pc-x

Christian

Re: Basf 6104 Assy 8118 jumper named Bx

[Christian Corti via cctalk]

On Sun, 18 Oct 2020, "Enrico email.it" wrote:

I was looking for the BASF 6104 drive manual.


Did you ask on classiccmp? If yes, I must have overseen that. Because, I 
have it on our FTP server since a long time ;-)

ftp://computermuseum.informatik.uni-stuttgart.de/basf/BASF6104_Aug1981.pdf

Christian

Re: Basf 6104 Assy 8118 jumper named Bx

[Christian Corti via cctalk]

On Sun, 18 Oct 2020, "Enrico email.it" wrote:

on internet I find the one related to ASSY 81098 (where the jumpers have the

[...]

while instead I am looking for the one related to ASSY 81118 (in which the


Sorry for the noise, I have missed the part about the assy number. I don't 
have the one you are looking for.


Christian

Re: Floppy disk: one drive per face

[Christian Corti via cctalk]

On Thu, 5 Nov 2020, "Enrico email.it" wrote:

How should we configure 22disk to be able to do the same thing on the B side
of the same floppy disk?

Inserting Side 2 in the definition table is not enough 


Actually, it is almost that ;-)
I have a similar system, the fl100 floppy drive system, part of the 
Grundig ptc100 (i.e. Mupid 2)
A: is side 0, and B: is side 1. Here's my 22disk definition for this. 
Please note, the trick is to define a two-sided format for the second side 
and first describe side 2 ! The definition of side 1 will be ignored 
because the CP/M directory won't specify any block beyond the first side.

And of course, the track order is by cylinder, not by side.

BEGIN MUP1  Mupid Seite 1 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 1
SECTORS 10,256
SIDE1 0 0,2,4,6,8,1,3,5,7,9
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END

BEGIN MUP2  Mupid Seite 2 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,256
SIDE2 0 0,2,4,6,8,1,3,5,7,9
SIDE1 0 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END



Christian

Re: R: Floppy disk: one drive per face

[Christian Corti via cctalk]

On Fri, 6 Nov 2020, "Enrico email.it" wrote:

So this for to read 1st face A:

BEGIN MUP1  Mupid Seite 1 - SSSD 96 tpi 5.25"

[...]

And this for to read the other side B:

BEGIN MUP2  Mupid Seite 2 - SSSD 96 tpi 5.25"

[...]

Absolutely correct :-)

Christian

Re: Floppy disk: one drive per face

[Christian Corti via cctalk]

On Fri, 6 Nov 2020, geneb wrote:

On Fri, 6 Nov 2020, Chuck Guzis via cctalk wrote:

[...]

I prefer my solution.  If you opt to format the second side, you'll end
up clobbering the first side in the process.   But then, what does this
bozo know?

FYI Christian, in case you weren't aware the "bozo" above /wrote/ 22disk. :D


I know that *g*
But I haven't read Chuck's solution before sending my post. And BTW my 
22disk entries are quite old (I think 15 years or so) and the 
documentation[1] does not mention the keyword "EAGLE". So how could I know 
about it??


Christian

[1]
File 22DISK.DOC from the 22DISK V1.44 package
"[...]
  22DISK

A CP/M-to-DOS Diskette Interchange Utility

   Version 1.40, September, 1993

 Copyright 1988-1993, Sydex, Inc.
[...]
"

The README
"22DISK Version 1.44

 Distribution Information


  October, 1996
[...]
"

Re: NEC NEAX IVS2 PBX with NEAXMAIL AD-8 - hard drive clone, issues

[Christian Corti via cctalk]

On Sun, 29 Nov 2020, Liam Proven wrote:

If there are any errors on the drive, I would recommend GNU
``ddrescue``. Do not confuse this with the older (but still
maintained) dd_rescue which is the product that inspired the GNU one;
the newer one is more capable.

It images but skips and continues on error, whereas ``dd`` will simply fail.


Without havingh read the man page of ddrescue, does it do more magic than 
"dd conv=noerror,sync" ?


Christian

Re: RL02 Tracking

[Christian Corti via cctalk]

On Mon, 21 Dec 2020, Aaron Jackson wrote:

The status currently is that the heads will load, and the ready lamp
flashes as the heads wobble back and forth very slightly, trying to lock
onto the outer servo guard band. Probing TP2 of the read/write module, I
can see the S1 servo burst flash (roughly in time with the ready
lamp). If I disconnect power to the servo motor, I can manually move the
head onto the outer guard band (less than a mm away) and monitoring the
position signal (TP15 on the drive logic module) shows this to be close
to 0. So, I'm very confused.


I've had almost the identical problem with a RL02 drive from a friend. It 
would start and load the heads, but the ready light would flicker or not 
even come on. After a measuring session I discovered that if I manually 
select the other head, everything would be fine. And if I disabled the 
servo motor I could manually lock onto the track on side 0, but then side 
1 was out of alignment. So the alignment between the two heads was wrong 
and I had then aligned one of the heads so that the two would lock onto 
their corresponding track. The drive works fine since then.


Christian

Re: APL\360

[Christian Corti via cctalk]

That reminds me of the APL\360 implementation running on the IBM 5100 and 
5110 using a rudimental System/360 emulator written in PALM machine code 
stored in the APL Executable ROS. The APL interpreter is stored in the APL 
language ROS and was accessed like an I/O device, i.e. the emulator 
fetched the 360 instructions with instructions like GETB and so on.


Also, I *think* that the PALM assembler used by IBM was written in APL, at 
least that's the impression I got when reading the documents from H. J. 
Myers "Instructions for the use of the Assembler Generator", and IBM 
report no. ZZ20-6431 "A Fast Assembly Technique Using APL"


Christian

Re: Greaseweazle

[Christian Corti via cctalk]

On Mon, 1 Feb 2021, Fred Cisin wrote:
If you are READing 8" disks, and ONLY READing, then you can get away with a 
simpler caable.  The main time that you might need the fdadap is for TG43 for 
writing.  But, the fdadap is a convenient way to not have to make a cable.


You only need the TG43 signal for old drives. All the 8" drives that I 
use with a PC or BeagleBone (with a modified mfmreader software) don't 
need this signal.


Christian

Re: Greaseweazle

[Christian Corti via cctalk]

On Mon, 1 Feb 2021, Al Kossow wrote:
Imagedisk, even though it spends way too much time with the heads 
spinning on the media at least does real-time retries. the problem is 
you also need to be able to stop and assemble a complete image by 
splicing together multiple partial attempts.


Well, isn't that logical? ;-)
I do this with my Linux implementation of IMD, and I do this with my 
floppy version of the mfmreader: immediately abort an operation when there 
are noises coming from the media, clean, restart at one/two cylinders 
before the forced abort, etc. and then "splice" together the individual 
read attempts.
You can't do real-time retries when reading at the flux level if you have 
no idea of the format. So often, it's better to sample a disk several 
times in case that the later processing reveals bad sectors. So often 
enough you can get an error free image produced from several samples.
The toughest part of course is the "PLL" that you need in software to lock 
to the bit rate.


Christian

Re: Greaseweazle

[Christian Corti via cctalk]

On Tue, 2 Feb 2021, Al Kossow wrote:

Do you make these available online?

I found your version of IMD here 
ftp://computermuseum.informatik.uni-stuttgart.de/utils

not under source control.


Ups, I see that this is a very old version. I'll update this with my 
current version and I'll write some notes on the usage etc. But it will 
need some time, the source is on my PC at work and currently doing home 
office.


I hate the fact that there are dozens of siloed projects in this problem 
space.


Yes, me too. It started several years ago as a "quick" way of imaging 
floppys on my PC that obviously is Linux only. But now, I think I could 
just publish it and have everyone play with it :-)


Christian

Re: Greaseweazle

[Christian Corti via cctalk]

On Tue, 2 Feb 2021, Al Kossow wrote:

Copy protection is just a pain in the ass.

A tiny, tiny fraction of what I work with has any and
I'm very happy it is mostly used on consumer computers
which are being archived by others so I don't have to.


:-))
This is also my attitude. I just don't care about fancy copy protection 
schemes, it is not my domain.


Christian

Re: One more thing to fix... HP9000/380 power supply

[Christian Corti via cctalk]

On Thu, 11 Feb 2021, carlos_muri...@ieee.org wrote:
to diminish it. Argh.  A month ago my trusty HP9000/380 ran just fine and I 

[...]
on; the power supply is dead.  So I unracked the pile of drives and the 
computer, checked for obvious things (the fuse is fine, and nothing in the 
power supply is swelled up or leaking, or browned by heat; visually, it looks 
new; the HV caps seem to hold a charge).  I need the schematics for the power


I recently repaired a 9000/310 power supply. The fault was very obvious if 
you are experienced with the components used. My machine was built in 
Germany (Böblingen) and has a German power supply that uses electrolytics 
from Frako (the golden caps). They tend to simply short from one moment to 
another. In this case one of them shorted the +12V rail and thus the power 
supply shut down. No other blown parts or fuses. Just find the shorted cap 
and replace it :-)


Christian

Re: Systems Concepts SC-4 computer

[Christian Corti via cctalk]

On Mon, 15 Feb 2021, Eric Moore wrote:

Yes, SEL was referred to as systems, but like I said that PDF does not seem


I still have problems seeing SEL referred to as something different as 
"Standard Elektrik Lorenz" (later part of ITT) who made for example the 
ER56...


Christian

Re: TI 960

[Christian Corti via cctalk]

On Sun, 21 Feb 2021, Al Kossow wrote:

Not very often you see paper tape software for them


Unfortunately I haven't found *any* software for the 960, yet.

Christian

Re: Need to have a roll of paper punch tape read by a tape reader and printed

[Christian Corti via cctalk]

On Tue, 9 Mar 2021, Vincent Slyngstad wrote:
I am a cctalk subscriber, but I don't seem to be getting messages reliably 
any more.  So, I'm replying to the reply, as I never got the original query.


Interesting, I did not get the original message either...

Christian

Re: Hard To Believe This Person Is Serious

[Christian Corti via cctalk]

On Fri, 26 Mar 2021, Guy Dunphy wrote:

At 05:45 PM 25/03/2021 -, you wrote:

https://www.ebay.co.uk/itm/313467585213

Seller is German. Of course they are serious.
The real question is whether they are sane.


The better questions are:
Why is the price marked in GBP and why doesn't he ship to Germany?
(This is what Ebay Germany tells me!)
So I absolutely agree with Ali concerning stock non-availability and the 
seller just being a broker.


Christian

Re: punching paper tape

[Christian Corti via cctalk]

On Fri, 26 Mar 2021, Paul Koning wrote:
Some machines used 7-track paper tape that is narrower than 8 track 
tape.  I thought Whirlwind was one of those.


Yes, the LGP-30 uses 7-tack paper tape as well. Normal 8 track paper tape 
is 25.4mm, 7 track tape 22.2mm. The latter is absolutely unobtanium... (I 
think we have one or two spools).


Christian

Need a BASIC expert

[Christian Corti via cctalk]

Hi,

I'm trying to find out if the BASIC dialect that was available for the 
MINCAL computers (aboutn 1971) was something derived from another "system" 
or whether it was an own dialect.


Some characteristic instructions that I can't find somewhere else are:
- Formatted output with PRINT FOR()
  Example: PRINT FOR(F5.0)500.1
- Computed GOTO with GOTO  OF n1,n2,...
  Example: GOTO A+B+1 OF 100,20,50
- Presence of "DEF FN", lack of RESTORE for DATA/READ constructs.

This BASIC must have been around 1970-1972.

Christian

Re: Need a BASIC expert

[Christian Corti via cctalk]

On Wed, 21 Apr 2021, it was written

If there are FORTRAN-esque commands added to the core Dartmouth version I
would search for another instance prior to MINICAL where this was done.

Back then BASIC flavors and adaptations were becomming common so it may
simply be MINICAL BASIC would have been just as easy for a period
programmer to whip up from scratch.


Minor correction: it's MINCAL (as in Dietz MINCAL), not MINICAL.

Christian

Re: Need a BASIC expert

[Christian Corti via cctalk]

On Wed, 21 Apr 2021, Brent Hilpert wrote:

It's not clear what you're looking for:
 1. A possible predecessor/origin for the source code or design of the MINCAL 
interpreter,
 2. or, earlier BASIC implementations that had the language features you 
mention.


Well, both with the focus on 1.
I'm trying to find out if there were other earlier implementations of the 
languages that were available for the MINCAL 500 series. Apparently we 
have the only existing system, and all software seem to be lost, so I 
thought I might try to recreate some of it by finding references/sources 
from other systems. I want to start with the BASIC interpreter.


Christian

Re: ISO intel iPDS-100 w/8085 pod (UK)

[Christian Corti via cctalk]

On Fri, 23 Apr 2021, Adrian Graham wrote:
I just got pipped on an auction for one of these last night, clearly 
someone needed it more than me and I hope it was for a real usage reason 
and not just to add to their collection of MDS-related machines.


I?ve been looking for an 8085 ICE for ages now to help troubleshoot my 
STC Executel phone systems so this seemed like an ideal opportunity to 
get my hands on one but hey, that?s how auctions work. This one also has 
an external 37 pin floppy interface so I was hoping I could hook up an 
8? drive to be able to read the Executel source floppy disks I have.


Reminds me that we got three iPDS-100 several weeks ago. Two have 
additional bubble memory modules, and there's one extra external floppy 
drive. And yes, there are some 8085 ICE and EPROM programmes with them ;-)

Very nice systems!

Christian

Re: DEC PDP-11/45 backplane +5 ECO

[Christian Corti via cctalk]

On Wed, 28 Apr 2021, Fritz Mueller wrote:

On Apr 28, 2021, at 9:51 AM, Al Kossow via cctalk  wrote:

I have other 45/70 drawings that i haven't pdf'ed
I need to see if they are different revs than what I already have


Ohh...  I'd be very, *very* interested to see versions of the /45 
drawings other than the two sets that are commonly available!


I should fetch the drawings from my 11/45 from my parent's home the next 
time I visit them. I would then scan them regardless whether they are 
already available or not ;-)


Christian

Re: Melted computer feet

[Christian Corti via cctalk]

On Thu, 20 May 2021, David Collins wrote:

Orange based cleaners are also good - the ones that remove stickers etc


That will dissolve plastics! Don't use orange based cleaners. I just use 
normal 97% ethanol (called Spiritus here). That will work just fine.


Christian

Re: IBM Logic IC equivalency information needed

[Christian Corti via cctalk]

On Fri, 11 Jun 2021, Santo Nucifora wrote:

I am currently working on an IBM 5100 that has some issues. I know for
certain that the 5100 has a bad graphics controller card so I need to dig
into component level replacements for those ICs I can replace. I have a
list of logic chip equivalents to the IBM part numbers that are written on
the chips but I don't think it's 100% accurate because IBM part number
1582601 comes back as 74151 "DATA SEL/MUX" but when I use one of those
cheap logic chip testers (that is surprisingly accurate), it comes back as
a 74157. For the record, if I test a 74151, it comes back as a 74151 so the
tester is correct. I just want to make sure the table I have is accurate
and that the tester is not 100% accurate or if that chip has failed and
tests like a 74157 in it's state.

This is the current list I am using that I got from somewhere but I don't
recall where:
https://vintagecomputer.ca/ibm-vintage-logic-chip-equivalency-list/
Does anyone have an IBM logic chip equivalency table for 74 series logic
chips?


This list looks like a faulty transcription of my list here:
ftp://computermuseum.informatik.uni-stuttgart.de/ibm/ibmparts.txt

In my list, it is "1582601 74157 DATA SEL/MUX".
This list came from some IBM internal copies with unknown source.

Christian

Re: IBM Logic IC equivalency information needed

[Christian Corti via cctalk]

On Sat, 12 Jun 2021, Tony Duell wrote:

I wonder if in the original list, a '1' was misread as a '7' or vice
versa. I am told that in some countries the '7' is conventionally
written with a crossbar across the downstroke to avoid this. My father
always did this, for all it is not common in England.


In Germany, we *always* write a bar across the 7. I don't like uncrossed 
sevens because they are ugly ;-) and hard to distinguish from a 1.


Christian

Re: VT340 Emulation

[Christian Corti via cctalk]

On Mon, 21 Jun 2021, Ethan Dicks wrote:

I would love some sample ReGIS files, color or B&W.  Anything, really.


You can use GNUplot with the terminal type set to ReGIS.

Christian

Re: Install Floppies (Was: Compaq Deskpro boards/hard drives from

[Christian Corti via cctalk]

On Mon, 26 Jul 2021, Peter Corlett wrote:
When writing, PC-style disk controllers scan for the appropriate sector 
header then switch to write mode to overwrite the old sector data. This 
requires guard bands between sectors and sector headers. The PC's


This is not called a guard band. A guard band is the erased zone between 
tracks. What you mean is called sector gap, there are multiple gaps 
between sector headers and sector data.


Christian

Re: PC floppy disk sets avaialble free

[Christian Corti via cctalk]

On Mon, 9 Aug 2021, Al Kossow wrote:

Whatever happened to PRIVATE replies.

It isn't even that hard to do, you just have to copy their source adr from 
the message, since this list's default reply is to the whole

fsckin' list


That's why I have a procmail rule that fixes that:

REPLYTO_=`formail -cXReply-To: | cut -d',' -f1 | sed -e 's/Reply-To: //' | 
sed -e 's/\"/\\\"/g'`


:0 fw
* ^To:.*classiccmp|^Cc:.*classiccmp
| sed -e 's/\[cctalk\] //g' | formail -i "From: $REPLYTO_" -i "Reply-To: 
\"General Discussion: On-Topic and Off-Topic Posts\" 
"




Christian

Re: Scanning Suggestions (Bookmarks & Colour)

[Christian Corti via cctalk]

On Fri, 27 Aug 2021, Al Kossow wrote:
I didn't see an obvious example of ocrmypdf doing OCR in parallel on a 
single document


It does that by default. At least, it always uses all cores when I process 
a document with ocrmypdf.


Christian

Re: scanning a ton of documentation

[Christian Corti via cctalk]

On Wed, 22 Sep 2021, Jay Jaeger wrote:

B/W, CCITT Group 4 tiffs at 400dpi is what I do, but then I also


600 DPI should be the absolute mininum today. There is absolutely no 
reason to go below that for B/W.



and notify Al Kossow of an available contribution.


Hasn't worked for me in the past ...


Bitsavers will post process and create a searchable PDF


Since when?

Christian

Re: Unix or BSD for Dec PDP 11/34 and 11/45

[Christian Corti via cctalk]

On Fri, 17 Sep 2021, devin davison wrote:

I'm working to get my pdp 11/34  and 11/45 running. I was curious what
versions of unix or bsd would work on the machines i have. I wanted to set


I'm running 2.9BSD on both our 11/34 and 11/45.


If possible too, id like to be able to telnet in to unix or bsd.I was also
curious if a ethernet interface exists for my unibus systems, or if i could
SLIP/PPP serial to another machine,so i could telnet in as well as use dumb
terminals.


There isn't enough memory and overlay space available for Ethernet 
stuff in 2.9BSD.


Christian

Re: scanning a ton of documentation

[Christian Corti via cctalk]

On Wed, 22 Sep 2021, Al Kossow wrote:

Bitsavers will post process and create a searchable PDF


Since when?


I think I'll just step away from the terminal for a few hours.
I've been OCRing uploads for YEARS.


Ok, I didn't know that you do that for foreign scans, I thought you only 
OCR your own scans.


Christian

Re: scanning a ton of documentation

[Christian Corti via cctalk]

On Wed, 22 Sep 2021, Al Kossow wrote:

On 9/22/21 1:51 PM, Christian Corti via cctalk wrote:

Hasn't worked for me in the past ...

guess I picked a bad day to stop sniffing glue


Don't get me wrong, but I had written some emails in the last years 
offering stuff for bitsavers (downloadable from our FTP site). They never 
made it into the archives.


Christian

LINCtape images

[Christian Corti via cctalk]

Short question:
How do I transfer LINCtape images back to tape on a PDP-12? Ideally there 
is some binary program to load via papertape to format a tape and recreate 
it with data transfer over the console serial line.


Christian

SerialDisk (Re: LINCtape images)

[Christian Corti via cctalk]

On Fri, 29 Oct 2021, Vincent Slyngstad wrote:
There seem to be a couple of formats that were frequently used, and a third 
lesser used format.  One of the issues is that you have to go into 
maintenance mode, as far as I can tell, to determine the size of the block 
you just read into memory.


It seems so.
But I would need just a restore version of the program, capable of 
formatting the tape first.
I'm wondering if I am the first who wants to create LINCtapes from an 
image. There is a mention of using SerialDisk with the PDP-12 (a modified 
version by cjl), but I can't locate it :-(


Christian

Re: SerialDisk (Re: LINCtape images)

[Christian Corti via cctalk]

On Tue, 2 Nov 2021, Vincent Slyngstad wrote:
Another option would be to spin the data onto LINCtape with a TD8E, then 
mount the result on the PDP-12.  I think Dave is creating the images in the 
first place with either a TD8E, or possibly a custom controller.


I think he used a custom controller.
I have several TD8E controllers, but the TU56s are wired for the TC08, and 
one unit for the TC11.



https://github.com/drovak/os8diskserver

The current version should have no problems with the 8/I or with the PDP-12. 
(Maybe even the straight-8, but I can't remember checking if it is "increment 
and rotate" clean.  Doug might know.)


Thanks. I've seen this, but the doc/comments apparently don't reflect the 
changes and modifications so I was thinking that this is the unpatched 
version.


Christian

Re: LINCtape images

[Christian Corti via cctalk]

On Tue, 2 Nov 2021, Jay Jaeger wrote:
Here is a program I wrote for reading/writing tape images via XModem protocol 
for my PDP-12, and another for comparing two linctapes.


This is fantastic, thanks :-)
I hope this will help us in bootstrapping the PDP-12. At least I would 
like to have a tape with all the diagnostics.
For now, we are at least able to load programs with the BIN loader over 
the serial line with currently 9600 Baud. We need to get the second line 
working for SerialDisk.


Christian

Re: LINCtape images

[Christian Corti via cctalk]

On Wed, 3 Nov 2021, Jay Jaeger wrote:
It seems you didn't notice that I included two separate programs in my 
previous post:  XMTAPE and CMPTAP  ;)


I did, and I have found an error ;-)

0275  0361 7300  #WDFLSH CLA CLL
0276  0362 1073 0073 TAD XMCNT   [ IF COUNT==128.
0277  0363 1176 7600 TAD (0-128.
0300  0364 7450  SNA
0301  0365 5761 0361 JMP;WDFLSH  [ THEN JUST RETURN

The space for the return address is missing at the beginning of WDFLSH

Christian

Re: LINCtape images

[Christian Corti via cctalk]

On Thu, 4 Nov 2021, David Gesswein wrote:

On Wed, Nov 03, 2021 at 10:57:21AM -0500, Jay Jaeger wrote:


I have some LINCTape images with diagnostics.  Let me know if you need one
and I can send you the image.


I can add them to my browsble archive if you wish.
http://www.pdp8online.com/images/index.shtml


Thanks to you all, I've been able to do the first step in recreating 
LINCtapes. I have successfully extracted the MARK12 binary [1] from the 
dial.linc tape image and convert it into a BN that can be loaded with the 
BINLDR. We testet it yesterday and guess what, we could mark new LINCtapes 
on our PDP-12 without errors.

Next step is bringing up SerialDisk.

Christian

[1]
ftp://computermuseum.informatik.uni-stuttgart.de/dec/pdp12/MARK12.BN

Re: LINCtape images

[Christian Corti via cctalk]

On Fri, 5 Nov 2021, David Gesswein wrote:

Looks like your .BN isn't my sites BIN loader conversion. Did you try mine
and it didn't work or you had already done your own before I added it?


I made my own extraction from the image, but it is the same as yours. I 
had written my own little program just to learn understand the format of a 
DIAL tape and the data from your site.


Christian

Re: Intel 4004 turns 50

[Christian Corti via cctalk]

On Tue, 16 Nov 2021, ED SHARPE wrote:
The two contenders on tside leading g to the gold caphis question are 
white and Gold 4004. And. The white  and gold with leads showing through 
in the white material i


And now in English, please!

Christian

Re: IEEE-488 on the PDP-11

[Christian Corti via cctalk]

On Wed, 17 Nov 2021, Ethan Dicks wrote:

On Tue, Nov 16, 2021 at 6:09 PM Christian Gauger-Cosgrove

I kind of want to see now if an IBV11 and Commodore 1541 can be abused
into cooperating.


I think it could be done.  The IBV11 can certainly keep up with the
6502 in the drive that's banging out the IEEE-488 protocol.


Our Tektronix 4051 can talk to and use Commodore IEEE floppy drives for 
mass storage. It has a custom ROM extension for it.


Christian

Re: IEEE-488 on the PDP-11

[Christian Corti via cctalk]

On Thu, 18 Nov 2021, it was written

On Thu, Nov 18, 2021 at 3:15 AM Christian Corti via cctalk

Our Tektronix 4051 can talk to and use Commodore IEEE floppy drives for
mass storage. It has a custom ROM extension for it.


That's really cool.  There are a few non-Commodore systems that were
able to talk to Commodore floppy drives.  I didn't know the Tektronix
4051 was one of them.

Do you know if it works at the flie level or the block level?


As you wish, but normally at the file level. You can OPEN files, load 
BASIC programs with OLD and so on.

The documentation is available here:
ftp://computermuseum.informatik.uni-stuttgart.de/tektronix/tek4051/

It's only in German, though. The disk routines are part of loadable 
extenstions that can be loaded into a RAM Backpack module.


Christian

K12MIT on PDP-12

[Christian Corti via cctalk]

So, with the help of you here, I was able to create OS/8 LINCtapes and to 
run SerialDisk. Everything runs very fine.


Now comes the next thing: I want to have K12MIT, and it is no problem to 
compile or load the program.
*But*: When I start K12MIT I don't get the prompt. I see the welcome 
message, and it correctly identifies the machine as a PDP-12, but that's 
it. As I've found out it apparently overwrites its code, the processor is 
looping around address 3600-3620. Examining the memory reveals that the 
code at 3600 has been overwritten with junk. So it's clear that it won't 
run anymore. What happens? Was anyone else able to run K12MIT on a PDP-12?


BTW the same binary runs fine on a PDP-8, be it a real machine or SIMH.

Christian

Re: K12MIT on PDP-12

[Christian Corti via cctalk]

On Wed, 24 Nov 2021, Chris Zach wrote:

Do you have a running pdp12?


Yes :-) It is completely working including the display and both LINCtape 
drives.


Christian

Re: K12MIT on PDP-12

[Christian Corti via cctalk]

On Wed, 24 Nov 2021, Vincent Slyngstad wrote:
Are you running SerialDisk on the same DP12 that K12MIT is trying to use? 
That might not work well, though I'm not sure why K12MIT would commit suicide 
about it.


Hmm... good point, I think that I have tried both, from LINCtape and from 
SerialDisk. I know, the latter won't work, but at least I should get the 
prompt, no?


I haven't had much use for K12MIT -- the tools that come with the latest 
SerialDisk can take apart and rebuild/modify bootable/server images, so I 
just copy whatever to or the directory those tools are using and rebuild the 
image (or re-explode the server image and copy it out, to go the other way).


I haven't understood the tools to build these disk images. There is no 
documentation IIRC. But I use SIMH and have a transfer disk image that I 
can mount with SerialDisk. There is one nuisance, though: SerialDisk won't 
see the updated image unless restarted. The advantage of SIMH is that I 
can "import" paper tape images (BIN or ASCII). That is something even PUTR 
can't accomplish.


Christian

Re: K12MIT on PDP-12

[Christian Corti via cctalk]

On Thu, 25 Nov 2021, Christian Corti wrote:

On Wed, 24 Nov 2021, Vincent Slyngstad wrote:
Are you running SerialDisk on the same DP12 that K12MIT is trying to use? 
Hmm... good point, I think that I have tried both, from LINCtape and from 
SerialDisk. I know, the latter won't work, but at least I should get the 
prompt, no?


Just tried without SerialDisk... no difference. K12MIT is broken on the 
PDP-12.


Christian

Re: K12MIT on PDP-12

[Christian Corti via cctalk]

On Thu, 25 Nov 2021, Christian Corti wrote:
Just tried without SerialDisk... no difference. K12MIT is broken on the 
PDP-12.


I've found the bug. Charles Lasner broke PDP-12 support (and probably also 
older PDP-8 models like 8/I) with his additions to support the DECmate 
family. The location is at 0206, labelled SETBAUD. This should be a NOP on 
standard systems, but is overlayed by an IOT to set the baud rate on a 
DECmate 1. This results in a 6413 instruction (because I have assembled it 
for the second serial port on 40/41). This instruction always skips (as 
the transmitter done flag is always set), thus jumping into a 4411 that is 
the address of a CRLF to be printed but executed as a JMS into nirvana.
The very same code runs fine on a PDP-8/E with a KL8/E interface that 
apparently either ignores this instruction or, by other means, has the 
flag cleared.


If patching location 0206 to 7000 (NOP), K12MIT will run on a PDP-12.

Sending files works, but receiving seems to be broken. Most of the times, 
the sending Kermit aborts the transfer to the PDP-12 with a 
out-of-window-NACK error (confirmed by looking at the protocol debug log). 
K12MIT sends a NACK to a previous packet that it already ACK'ed *after* 
receiving the next data packet.


Here's the code fragment:

1827   000200  5777  CLOOP,  JMP I   (INITIALIZE)/ INITIALIZED  CLA 
CLL  /024 CJL
1828   000201  4577  JMS I   [CRESET]/RESET CONSOLE ROUTINE 
STUFF
1829   000202  3002  DCA ABFLAG  /CLEAR ABORT FLAG  
 /044 CJL
1830   000203  3105  DCA REMWAIT /CLEAR REMOTE FLOW CONTROL 
WAIT /049 CJL
1831   000204  4324  CLDMZAP,JMS DMINIT  /INITIALIZE DECMATE PORT   
 /048 CJL
1832
1833 /   THE  PREVIOUS  INSTRUCTION  IS  FOR  DECMATE  
OPERATION  ONLY.THE  DEFAULT
1834 /   INSTRUCTION IS FOR KL8 INTERFACES ONLY.
1835
1836   0204  *CLDMZAP/OVERLAY DECMATE CODE  
 /048 CJL
1837
1838   000204  7000  CLDMZAP,NOP /DON'T INITIALIZE DECMATE 
PORT  /048 CJL
1839   000205  1007  TAD RATE/GET BAUD RATE
1840   000206  6363  SETBAUD,MSB /SET REMOTE BAUD RATE  
 /050 CJL
1841
1842 /   THE PREVIOUS INSTRUCTION IS FOR DECMATE II 
OPERATION ONLY.  /050 CJL
1843
1844   0206  *SETBAUD/OVERLAY DECMATE II CODE   
 /050 CJL
1845
1846   000206  7000  SETBAUD,NOP /NOT APPLICABLE ON DECMATE 
I/050 CJL
1847
1848 /   THE  PREVIOUS  INSTRUCTION  IS  FOR DECMATE I 
OPERATION  ONLY.THE  DEFAULT
1849 /   INSTRUCTION IS FOR KL8 INTERFACES ONLY.
1850
1851   0206  *SETBAUD/OVERLAY DECMATE I CODE
 /050 CJL
1852
1853   000206  6413  SETBAUD,RSBIOT  /SET REMOTE BAUD RATE  
 /050 CJL
1854   000207  4576  JMS I   [SCRIBE]/DO A  
 /025 CJL
1855   000210  4411  CRLF/, 
 /025 CJL
1856   000211  4576  JMS I   [SCRIBE]/GIVE THEM THE 
 /025 CJL
1857   000212  4457  PRMTMSG /PROMPT MESSAGE
 /025 CJL
1858   000213  4776  JMS I   (LININP)/GET INPUT LINE FROM USER


Christian

[cctalk] Re: Siemens 4004 mainframe pictures on bitsavers

[Christian Corti via cctalk]

On Tue, 24 Sep 2024, P Gebhardt wrote:

out of curiosity: Does anybody know where the two pictures of the Siemens 4004 
CPU uploaded on
http://bitsavers.org/pdf/siemens/4004/Model_15/pictures/
where taken? Are these from the unit being part of the SAP collection at 
CHM? 


No, thanksfully this machine is still in Germany. It is nor far from me 
BTW ;-) I know where it came from and who has it now. It is complete 
with peripherals (storage, card reader, console, printer) and 
hopefully, will be running soon again :-)


Christian

[cctalk] Re: Siemens 4004 mainframe pictures on bitsavers

[Christian Corti via cctalk]

For those who doesn't know it:
The Siemens 4004 was basically a rebadged RCA Spectra 70, so this is a
RCA 70/15. Maybe technical/service manuals for this system come up.
(the owner already searched everything incl. bitsavers, of course)

Christian


On Mon, 23 Sep 2024, Adrian Stoness wrote:

it was being talked about on one of the discords voice chats the other day.
the guy is looking for manuals for it so if u got them upload them

On Tue, Sep 24, 2024 at 1:17?AM P Gebhardt via cctalk 
wrote:


Hello list,

out of curiosity: Does anybody know where the two pictures of the Siemens
4004 CPU uploaded on
http://bitsavers.org/pdf/siemens/4004/Model_15/pictures/

where taken? Are these from the unit being part of the SAP collection at
CHM?

Cheers,
Pierre


-
http://www.digitalheritage.de

[cctalk] Re: Might be antique computer parts

[Christian Corti via cctalk]

On Wed, 2 Oct 2024, Tom Gardner wrote:
Speaking of high profit margins: on the 1620, there was an extra cost 
option called "direct seek".  I don't know if involved a jumper cut or 
some actual circuitry (an adder, most likely).  We didn't have that, and 
the result is that a seek from cylinder x to cylinder y was done by a 
full retract to cylinder 0, followed by a seek out to y.  It was amusing 
to watch the shaking resulting from a simple "incrementing seek test" -- 
seek to cylinder i for i = 0 to 99.  Those last few seeks would take the 
better part of a second.


Here's a link to a video that I took last year of a 1311 doing seeks (it 
is running on a 1401): https://www.youtube.com/watch?v=LXDVRP9pfyw


Christian

[cctalk] Re: Dysan Alignment and Performance Testers

[Christian Corti via cctalk]

On Thu, 3 Oct 2024, Chris Elmquist wrote:

Just curious if you had a known "good" drive, a golden unit so to speak,
that was well aligned with an authentic alignment diskette-- could you
then use that drive to write plain old data diskettes that the downstream
users would then align their drives to?


Yes, that is what you do in practice. Although I have a bunch of alignment 
disks for 5.25" 48tpi and 96tpi (and I guess for 8", too), you don't need 
them for pure track alignment. I mean, the drive was once good. I can't 
see how a solid drive can get out of alignment without physical impact. 
The CBM floppy drives seem to a case of cheap drive mechanics. But I guess 
that comes from the missing track 0 sensor, thus the head carrier 
physically hits the chassis, and this can cause dealignment.


I also know the cats eye patterns etc. from disk drive alignment packs 
(e.g. RK05 alignment cartridge). But do I _need_ them for track alignment?


Christian