Re: Sunday brain tickler

[Chuck Guzis]

On 01/08/2017 06:25 PM, allison wrote:

> I haven't ground on what it may be but there are four likely 
> directory/catalog cases.


I've certainly seen my share of various filesystems.  In fact, I can
laboriously reconstruct the original files, there being only 70 1200
byte blocks on the disk.  I thought that having a file name might be useful.

I'm just a bit weary of deciphering this one-off and can't get my mind
in the right frame to paw through the directory structure.

But I put it to you that there exactly 72 (or 71) entries in this list
and there are exactly 70 1200-byte blocks--and, make no mistake, they
are 1200-byte blocks with a definite format--a header followed by text.
Short blocks are denoted by a control character sequence, after which
old data to the end of the block may be found.  So it's quite possible
to splice the bits together into complete documents.

But that's cheating--I'd like to understand how the first block
directory dictates the relationship between blocks and any file names.

So let's look at the directory again--note the 11th bytes all either
have values less than 70 (decimal).  I'm guessing that that's a forward
link to the next block--note that 7F is the only out-of-range value
present in this column.  I suspect that this is the end-of-file marker.

This is all guessing at this point.

--Chuck

Re: Stripping an RA80

[allison]

On 01/08/2017 01:46 PM, Robert Armstrong wrote:
>> Tony Duell  wrote:
>> R80 the lines are outputs from the drive giving the coding of the ready lamp 
>> cap
>   I was always thought that the R80 had to be unit #0 to function, but I 
> admit that I've never tried anything else.  I wonder if that's not true??  
> The RL02 drive(s) on the IDC can be any of units 1, 2 or 3.  
>
>> The HDA is the only major unit I can't repair (yet!).
>   Yeah, same here.  In addition to the 11/730 with one (dead) R80, one RA81 
> and one RA82, I have a MicroVAX-III with an RA82 drive.  Keeping them all 
> working has been a real challenge.  Fixing the electronics and mechanical 
> parts isn't too bad, and I have plenty of spares, but the HDAs don’t seem to 
> be very reliable.  I get the impression that they were designed with a finite 
> number of spin up/spin down cycles in mind, and once you exceed that limit 
> they die.  Fortunately I've been able to find spares for the RA81 and RA82 
> HDAs, but R?80s seem to be pretty rare.
>
> Bob
>
>
Depending on vintage of those HDAs they may have been in the large pool
of SNs that had bad (incorrect) adhesive
used to assemble the platters and would after about 1.5-2.2 years of
spinning would have the glue migrate out
and take the heads.  It was a major program to recover those that had
not yet failed and replace them and make
nice to those that had failures.   The adhesive used was substituted in
manufacturing without ECO.  The internal
program was costed at something north of 100M$ to achieve.

All my VAXen and PDP-11s use RX, RL, RD, and RZ media due to
reliability.  The only ones worse was RA60 then RC25.

Allison

Allison

Re: Sunday brain tickler

[allison]

On 01/08/2017 09:09 PM, Chuck Guzis wrote:
> On 01/08/2017 04:42 PM, william degnan wrote:
>> Inverse 8085?
> I don't think so.  If it helps, here's the first few lines of the
> "directory":
>
> 000:  00 a1 7a c1 c0 00 00
> 0007:  00 00 00 00 00 00 00 80 1a 02 38 00
> 0013:  a1 7a c1 c0 00 00 00 00 1b ff 00 00
> 001f:  5c 25 15 1b 4c 40 00 00 ff ff 37 05
> 002b:  94 2f 38 40 00 00 00 00 ff 8f 31 01
> 0037:  c4 a3 75 6a ab 52 00 00 ff 85 25 05
> 0043:  94 2f 38 40 00 00 00 00 ff 02 0f 02
> 004f:  c4 a3 75 6a ab 52 00 00 ff b6 09 04
> 005b:  94 2f 38 40 00 00 00 00 ff 03 02 03
> 0067:  c4 a3 75 6a ab 52 00 00 ff 01 12 01
> 0073:  d0 7f 9f 12 1f bd 53 28 ff ff 7f 02
> 007f:  c4 a3 75 6a ab 52 00 00 ff 01 2b 00
> 008b:  c4 a3 75 6a ab 52 00 00 ff 83 28 04
> 0097:  c4 a3 75 6a ab 52 00 00 ff 01 38 00
> 00a3:  94 2f 3e 80 00 00 00 00 ff 01 1d 00
> 00af:  94 2f 4b 00 00 00 00 00 ff 03 35 05
> 00bb:  94 2f 4b 00 00 00 00 00 ff ff 3e 06
> ...
>
> There are no other tables on disk. The disk itself is hard-sectored,
> with a sector length of 150 bytes and 16 sectors per track.  They're
> interleaved 3:1 and grouped into blocks of 1200 bytes.  The directory
> would correspond to block 0 and there are 72 entries in it, less the header.
>
> I can get the raw text, but how it's linked together and what file names
> might is still a mystery.
>
> --Chuck
>
>
I haven't ground on what it may be but there are four likely
directory/catalog cases.

Bag and tag, the file name starting block (or group of blocks) and
number of blocks.
usually byte pairs or longer ((16, 24, or 32bits) to get enough
addressing and large
enough byte counts.

CP/M like with entries for file name then a short list of allocation
blocks, additional entries
if the file is larger and needs for allocation blocks.  FYI CPM it can
be byte pairs or
single byte allocation list.

unix like with a simple filename and pointer to Inode there the metadata
and block list is.

Last case is a reserved set of blocks that are allocated as a linked
list and the directory
block has the filename and point to the start of the list.  Like unix
that can easily support
subdirectories.

None of those are processor specific but the cpu used often determines
things like if
there is bit packing.

As to radix, anything is possible also simeple things like high bit of a
8bit byte suggests
a control code or extended characters (or several things).

Allison

Re: pdp-11 assembly standards

[Don North]

On 1/8/2017 9:10 PM, Brent Hilpert wrote:

OK, what was the standard (if there was one) number-base syntax for PDP-11 
assembler?

Despite all the PDP-11 assembly info on web sites, this seems to be a buried 
bit of info.
One assembler doc uses a prefix of "", another specifies octal as default and 
prefix of zero for decimal (opposite of the common C-derived standard . . great).

Is this for example standard?:

BIT #, @#  ; test 2^7 bit at address octal 
177564

(I'm just trying to make some written commentary consistent with common policy.)



MACRO11 Language Manual v5.5 section 6.4

All numbers are octal radix, unless the default radix is changed via the .RADIX 
N directive (N can be 2, 8, 10, or 16). N blank resets the radix to octal.


So 0100, 100 would be octal 100, decimal value 64.

Any number followed by a period (decimal point) is forced to be base 10.

So 100. would be decimal 100, octal 144.

Prefix operators ^B (binary), ^O (octal), ^D (decimal), ^X (hexadecimal) force 
the following digits/characters to the designated radix.


So ^B101000 == ^O50 == ^D40 == ^X28 all represent the same value (decimal 40.) 
irrespective of the current .RADIX N setting.

Re: Fwd: Stinky screwdrivers

[Chuck Guzis]

On 01/08/2017 08:16 PM, Al Kossow wrote:
> 
> I sent this out to some friends at the end of December

I've got a few large (not the torque-handle thing) from the late 60's
Xcelite nutdrivers.   They don't smell and they're in fine condition.

Must have been a formula change at some point.

Reminds of the issue with cellulose acetate-based film and tape.  Most
conscientious people placed said objects in airtight storage containers,
which apparently is exactly the thing *not* to do.  I'm not aware of any
process to reverse the decomposition.

Old plastics in general are a nightmare for museum conservators.

--Chuck

pdp-11 assembly standards

[Brent Hilpert]

OK, what was the standard (if there was one) number-base syntax for PDP-11 
assembler?

Despite all the PDP-11 assembly info on web sites, this seems to be a buried 
bit of info.
One assembler doc uses a prefix of "", another specifies octal as default and 
prefix of zero for decimal (opposite of the common C-derived standard . . 
great).

Is this for example standard?:

BIT #, @#  ; test 2^7 bit at address octal 
177564

(I'm just trying to make some written commentary consistent with common policy.)

Re: Fwd: Stinky screwdrivers

[jim stephens]

On 1/8/2017 8:16 PM, Al Kossow wrote:

Sadly, it looks like the good USA made hand tools will all have their plastic 
handles crumble eventually
though I have two Craftsmen nut drivers I bought in 1975 that are still perfect.

How many perished in liquid N2 back in the day.  So sad.

thanks
jim

Re: Sunday brain tickler

[Chuck Guzis]

Jim, that occurred to me right off the bat, but the disk has only 35
cylinders and is single-sided.

No file names in the body text.   The text itself isn't proprietary, but
merely an early cut of an already-published public report, so I have no
problem sharing any part of the disk image.

--Chuck





On 01/08/2017 07:55 PM, jim stephens wrote:
> I don't know the names, but the use of extents might be something going on.
> 
> I highlighted the c4a3 extent.  The last two columns maybe cylinder and
> sector number.
> 
> There may be a free count going on with the next to the last two bytes
> 0xff85 for instance in the first stick.
> 
> Since line 0x000 is odd, i wonder if it is volume related or other with
> the application of the disk.  I'd guess that line 0x0007
> is also possibly volume related.
> 
> The only deviating entry at 073 has a 7f in what I'm guessing is the
> cylinder column, so maybe an "erased" entry?
> 
> And for whatever reason, there are 6 bytes "live" in the beginning, the
> two bytes of 0x in all the entries as well.
> 
> As to the missing file names, I wonder if that data is in the text of
> the disk.  That was one way that file
> systems had to pay with variable length packed data since tables like
> this was necessary with fixed length.
> 
> I am guessing you don't want to share the file names, but I'd take the
> numbers in the cylinder and sector columns
> and see if you can spot something like filenames and the like.
> 
> I had a file system on a Microdata 1621 based mini that i wrote, and we
> put the directory entry in both the main
> VTOC and in the heading of the first sector of the file.  Thank god for
> that, as one time we had a malfunction and
> had to do a VTOC rebuild from scanning the entire disk, but that's
> another story.
> 
> Thanks
> Jim
> 
> On 1/8/2017 6:09 PM, Chuck Guzis wrote:
>> On 01/08/2017 04:42 PM, william degnan wrote:
>>> Inverse 8085?
>> I don't think so.  If it helps, here's the first few lines of the
>> "directory":
>>
>> 000:  00 a1 7a c1 c0 00 00
>> 0007:  00 00 00 00 00 00 00 80 1a 02 38 00
>> 0013:  a1 7a c1 c0 00 00 00 00 1b ff 00 00
>> 001f:  5c 25 15 1b 4c 40 00 00 ff ff 37 05
>> 002b:  94 2f 38 40 00 00 00 00 ff 8f 31 01
>> 0037:*c4 a3 75 6a ab 52 00 00 ff 85 25 05*
>> 0043:  94 2f 38 40 00 00 00 00 ff 02 0f 02
>> 004f:*c4 a3 75 6a ab 52 00 00 ff b6 09 04*
>> 005b:  94 2f 38 40 00 00 00 00 ff 03 02 03
>> 0067:*c4 a3 75 6a ab 52 00 00 ff 01 12 01*
>> 0073:  d0 7f 9f 12 1f bd 53 28 ff ff 7f 02
>> 007f:*c4 a3 75 6a ab 52 00 00 ff 01 2b 00*
>> 008b:*c4 a3 75 6a ab 52 00 00 ff 83 28 04*
>> 0097:*c4 a3 75 6a ab 52 00 00 ff 01 38 00*
>> 00a3:  94 2f 3e 80 00 00 00 00 ff 01 1d 00
>> 00af:  94 2f 4b 00 00 00 00 00 ff 03 35 05
>> 00bb:  94 2f 4b 00 00 00 00 00 ff ff 3e 06
>> ...
>>
>> There are no other tables on disk. The disk itself is hard-sectored,
>> with a sector length of 150 bytes and 16 sectors per track.  They're
>> interleaved 3:1 and grouped into blocks of 1200 bytes.  The directory
>> would correspond to block 0 and there are 72 entries in it, less the
>> header.
>>
>> I can get the raw text, but how it's linked together and what file names
>> might is still a mystery.
>>
>> --Chuck
>>
>>
>>
> 
> 


-- 
--Chuck
-

"The first thing we do, let's kill all the spammers."

Re: Don't put certain tool handles in with artifacts...acetic acid and butyri...

[COURYHOUSE]

Yep - -Al I  need to separate   my   Burroughs Xcelite tools  somehow  
form some of the other things.
Acetic acid will eat stuff... the Enigma  had a green acitate   filter in 
the lid... with the case closed it ate all the metal keytops rings up.  It 
was ghastly!   Ed#
 
 
 
 
 
In a message dated 1/8/2017 9:10:45 P.M. US Mountain Standard Time,  
a...@bitsavers.org writes:




> I found this interesting wondering why some tool  handles smelled  odd.

Xcelite is notorious for  this

Fwd: Stinky screwdrivers

[Al Kossow]

I sent this out to some friends at the end of December

 Forwarded Message 
Subject: Stinky screwdrivers
Date: Thu, 29 Dec 2016 08:51:02 -0800
From: Al Kossow 
To: Eric Schlaepfer , Kenneth Sumrall 
CC: Hedley Rainnie , Alvaro 


http://www.garagejournal.com/forum/archive/index.php/t-153147.html

I've been buying a lot of Xcelite tools lately, and was wondering why some of 
the handles stunk.

Sadly, it looks like the good USA made hand tools will all have their plastic 
handles crumble eventually
though I have two Craftsmen nut drivers I bought in 1975 that are still perfect.

Xcelite isn't made in the US anymore. Bought a #0 Super-tru Tip (no longer says 
USA) and it is absolute crap.


--

as an addendum, I just bought a new "Made in USA" Xcelite pliers, and the build 
quality was an embarrassment.

now I understand all the interest in used hand tools on eBay

Re: Don't put certain tool handles in with artifacts...acetic acid and butyric acid

[Al Kossow]

> I found this interesting wondering why some tool handles smelled  odd.

Xcelite is notorious for this

Don't put certain tool handles in with artifacts...acetic acid and butyric acid

[COURYHOUSE]

 
Don't put certain tool handles in with   artifacts... acetic acid and 
butyric acid EATS!
 
I found this interesting wondering why some tool handles smelled  odd.  - 
Ed Sharpe archivist  for SMECC
 
 "Tool handles  made of Cellulose Acetate Butyrate. A thermoplastic, it 
offers excellent UV and  solvent resistance that cellulose acetate doesn't 
offer. And it feels in the  hand like a natural substance, something that is 
almost intangible, like a tool  that is made by craftsmen, a characteristic 
that a polyethylene or polypropylene  handle does not have. CAB also offers no 
splinters like the older wood handles.  It also can be very clear. And when 
that plastic begins to degrade, it releases  free acetic acid and butyric 
acid."
 
Read  much much more here->
 
http://dwarmstr.blogspot.com/2013/02/why-toolboxes-and-tool-handles-stink.ht
ml

Re: Sunday brain tickler

[jim stephens]

I don't know the names, but the use of extents might be something going on.

I highlighted the c4a3 extent.  The last two columns maybe cylinder and 
sector number.


There may be a free count going on with the next to the last two bytes 
0xff85 for instance in the first stick.


Since line 0x000 is odd, i wonder if it is volume related or other with 
the application of the disk.  I'd guess that line 0x0007

is also possibly volume related.

The only deviating entry at 073 has a 7f in what I'm guessing is the 
cylinder column, so maybe an "erased" entry?


And for whatever reason, there are 6 bytes "live" in the beginning, the 
two bytes of 0x in all the entries as well.


As to the missing file names, I wonder if that data is in the text of 
the disk.  That was one way that file
systems had to pay with variable length packed data since tables like 
this was necessary with fixed length.


I am guessing you don't want to share the file names, but I'd take the 
numbers in the cylinder and sector columns

and see if you can spot something like filenames and the like.

I had a file system on a Microdata 1621 based mini that i wrote, and we 
put the directory entry in both the main
VTOC and in the heading of the first sector of the file.  Thank god for 
that, as one time we had a malfunction and
had to do a VTOC rebuild from scanning the entire disk, but that's 
another story.


Thanks
Jim

On 1/8/2017 6:09 PM, Chuck Guzis wrote:

On 01/08/2017 04:42 PM, william degnan wrote:

Inverse 8085?

I don't think so.  If it helps, here's the first few lines of the
"directory":

000:  00 a1 7a c1 c0 00 00
0007:  00 00 00 00 00 00 00 80 1a 02 38 00
0013:  a1 7a c1 c0 00 00 00 00 1b ff 00 00
001f:  5c 25 15 1b 4c 40 00 00 ff ff 37 05
002b:  94 2f 38 40 00 00 00 00 ff 8f 31 01
0037:*c4 a3 75 6a ab 52 00 00 ff 85 25 05*
0043:  94 2f 38 40 00 00 00 00 ff 02 0f 02
004f:*c4 a3 75 6a ab 52 00 00 ff b6 09 04*
005b:  94 2f 38 40 00 00 00 00 ff 03 02 03
0067:*c4 a3 75 6a ab 52 00 00 ff 01 12 01*
0073:  d0 7f 9f 12 1f bd 53 28 ff ff 7f 02
007f:*c4 a3 75 6a ab 52 00 00 ff 01 2b 00*
008b:*c4 a3 75 6a ab 52 00 00 ff 83 28 04*
0097:*c4 a3 75 6a ab 52 00 00 ff 01 38 00*
00a3:  94 2f 3e 80 00 00 00 00 ff 01 1d 00
00af:  94 2f 4b 00 00 00 00 00 ff 03 35 05
00bb:  94 2f 4b 00 00 00 00 00 ff ff 3e 06
...

There are no other tables on disk. The disk itself is hard-sectored,
with a sector length of 150 bytes and 16 sectors per track.  They're
interleaved 3:1 and grouped into blocks of 1200 bytes.  The directory
would correspond to block 0 and there are 72 entries in it, less the header.

I can get the raw text, but how it's linked together and what file names
might is still a mystery.

--Chuck

Re: Unknown keyboard

[Brent Hilpert]

Kyle Owen  writes:
> Does anyone have an idea what this keyboard went to? The "here is" key
> tells me it's likely a terminal, but the hex key pad is throwing me off.
> Pictures here: http://imgur.com/a/zTgR2

On 2017-Jan-08, at 6:17 PM, Brian Walenz wrote:
> I've got one in the metal case.  On the back is a property tag:
> 
> Teledyne Ryan Aeronautical
> E.T. "028400a"  [<- the 'a' in pen]
> Gov't I.D. "MDA9729530013"
> Prop. of "USAF"
> R-5051-2-REV.5-93
> 
> Where the stuff in quotes is from a typewriter, the rest is form
> boilerplate.  There are also some inventory control stickers from 1999 and
> 2001.
> 
> I made a new EPROM that made it output a unique code for each key, but I'd
> have to dig up the notes to say anything useful.  I never figured out what
> the daughter board was for and just removed it.


The daughterboard on the one in question has a 6402 on it, so can be expected 
to be a parallel to serial converter.

The daughterboard also has what appears to be "Ditronics" labeled on it.

A search turns up a currently existing Ditronics doing financial-world tech 
services, no idea whether it could trace back to the 80s keyboard.

Re: Unknown keyboard

[Brian Walenz]

I've got one in the metal case.  On the back is a property tag:

Teledyne Ryan Aeronautical
E.T. "028400a"  [<- the 'a' in pen]
Gov't I.D. "MDA9729530013"
Prop. of "USAF"
R-5051-2-REV.5-93

Where the stuff in quotes is from a typewriter, the rest is form
boilerplate.  There are also some inventory control stickers from 1999 and
2001.

I made a new EPROM that made it output a unique code for each key, but I'd
have to dig up the notes to say anything useful.  I never figured out what
the daughter board was for and just removed it.

b

Re: Sunday brain tickler

[Chuck Guzis]

On 01/08/2017 04:42 PM, william degnan wrote:
> Inverse 8085?

I don't think so.  If it helps, here's the first few lines of the
"directory":

000:  00 a1 7a c1 c0 00 00
0007:  00 00 00 00 00 00 00 80 1a 02 38 00
0013:  a1 7a c1 c0 00 00 00 00 1b ff 00 00
001f:  5c 25 15 1b 4c 40 00 00 ff ff 37 05
002b:  94 2f 38 40 00 00 00 00 ff 8f 31 01
0037:  c4 a3 75 6a ab 52 00 00 ff 85 25 05
0043:  94 2f 38 40 00 00 00 00 ff 02 0f 02
004f:  c4 a3 75 6a ab 52 00 00 ff b6 09 04
005b:  94 2f 38 40 00 00 00 00 ff 03 02 03
0067:  c4 a3 75 6a ab 52 00 00 ff 01 12 01
0073:  d0 7f 9f 12 1f bd 53 28 ff ff 7f 02
007f:  c4 a3 75 6a ab 52 00 00 ff 01 2b 00
008b:  c4 a3 75 6a ab 52 00 00 ff 83 28 04
0097:  c4 a3 75 6a ab 52 00 00 ff 01 38 00
00a3:  94 2f 3e 80 00 00 00 00 ff 01 1d 00
00af:  94 2f 4b 00 00 00 00 00 ff 03 35 05
00bb:  94 2f 4b 00 00 00 00 00 ff ff 3e 06
...

There are no other tables on disk. The disk itself is hard-sectored,
with a sector length of 150 bytes and 16 sectors per track.  They're
interleaved 3:1 and grouped into blocks of 1200 bytes.  The directory
would correspond to block 0 and there are 72 entries in it, less the header.

I can get the raw text, but how it's linked together and what file names
might is still a mystery.

--Chuck

Re: Sunday brain tickler

[william degnan]

Inverse 8085?

Bill Degnan
twitter: billdeg
vintagecomputer.net
On Jan 8, 2017 7:38 PM, "Chuck Guzis"  wrote:

> On 01/08/2017 04:24 PM, Jules Richardson wrote:
> > On 01/08/2017 10:03 AM, Chuck Guzis wrote:
> >> I'm looking at a sample of what I see as a directory of sorts and
> >> am attempting to decode the file names from it.  They're not
> >> anything as elegant as Rad50, but the encoding has escaped my weary
> >> brain.
> >
> > Hmm, do you have any clues to go on? Knowledge of what some of the
> > names might logically be, whether filename extensions were a concept
> > or not, whether uppercase/lowercase/punctuation in names was
> > supported etc.?
> >
> > What would be really handy I suppose would be a disk where the user
> > had written some of the document names on the label :-)
>
>
> About all I can offer is that the names may (not certain) include the
> string "LTER".
>
> Typical work for me, I'm afraid.  Keeps me young.
>
> --Chuck
>

Re: Sunday brain tickler

[Chuck Guzis]

On 01/08/2017 04:24 PM, Jules Richardson wrote:
> On 01/08/2017 10:03 AM, Chuck Guzis wrote:
>> I'm looking at a sample of what I see as a directory of sorts and
>> am attempting to decode the file names from it.  They're not
>> anything as elegant as Rad50, but the encoding has escaped my weary
>> brain.
> 
> Hmm, do you have any clues to go on? Knowledge of what some of the
> names might logically be, whether filename extensions were a concept
> or not, whether uppercase/lowercase/punctuation in names was
> supported etc.?
> 
> What would be really handy I suppose would be a disk where the user
> had written some of the document names on the label :-)


About all I can offer is that the names may (not certain) include the
string "LTER".

Typical work for me, I'm afraid.  Keeps me young.

--Chuck

Re: Sunday brain tickler

[Jules Richardson]

On 01/08/2017 10:03 AM, Chuck Guzis wrote:

I'm looking at a sample of what I see as a directory of sorts and am
attempting to decode the file names from it.  They're not anything as
elegant as Rad50, but the encoding has escaped my weary brain.


Hmm, do you have any clues to go on? Knowledge of what some of the names 
might logically be, whether filename extensions were a concept or not, 
whether uppercase/lowercase/punctuation in names was supported etc.?


What would be really handy I suppose would be a disk where the user had 
written some of the document names on the label :-)

RE: Stripping an RA80

[Robert Armstrong]

>Tony Duell  wrote:
>Well, actually I think you own an R80 but don't know it :-)
>As I understand it, the R80 had the sort-of SMD interface. 2 cables
>(60 and 26 wires). It's not SMD, there are significant differences, but anyway.

  Can't speak for it being an SMD interface, but the rest of this is correct.  
And as tony said, the R80 was used only in the VAX-11/730 with the IDC.  The 
IDC, with the help of the CPU microcode, turns the R80 into an MSCP drive and 
also controls up to three RL02 drives at the same time.  FWIW, you can put an 
R80 HDA in an RA80 drive and vice-versa without needing to reformat.  Don't 
know if that's true for the RM80 - I've never actually used one of those.

  I have an 11/730 in the garage with the IDC and R80 drive.  I've got lots of 
spares for the R80 drive itself, but only one HDA and that one is unusable due 
to too many errors.  Fortunately I also have a UDA-50 and two more RA8x drives 
in the machine so it's still usable.  It boots just fine from the UDA-50, but 
I'd love to restore the original drive.

  If anybody has an R?80 HDA that they'd be willing to part with, let me know!

Bob

RE: Stripping an RA80

[Robert Armstrong]

>Tony Duell  wrote:
>R80 the lines are outputs from the drive giving the coding of the ready lamp 
>cap

  I was always thought that the R80 had to be unit #0 to function, but I admit 
that I've never tried anything else.  I wonder if that's not true??  The RL02 
drive(s) on the IDC can be any of units 1, 2 or 3.  

>The HDA is the only major unit I can't repair (yet!).

  Yeah, same here.  In addition to the 11/730 with one (dead) R80, one RA81 and 
one RA82, I have a MicroVAX-III with an RA82 drive.  Keeping them all working 
has been a real challenge.  Fixing the electronics and mechanical parts isn't 
too bad, and I have plenty of spares, but the HDAs don’t seem to be very 
reliable.  I get the impression that they were designed with a finite number of 
spin up/spin down cycles in mind, and once you exceed that limit they die.  
Fortunately I've been able to find spares for the RA81 and RA82 HDAs, but R?80s 
seem to be pretty rare.

Bob

Re: More circuit help required please

[Adrian Graham]

On 08/01/2017 18:20, "Tony Duell"  wrote:

>> However, two of us bought units at the same time and the other one has a
>> little bridgeboard containing a 74LS244 that sends the RGB signals to a DIN
>> socket on the back of the case for an external monitor. I also can't see a
> 
> And in a sense there was...

Yep. I'm pleased we found that mod in the other unit because I made my own
bridgeboard and hooked the display up to a Microvitec CUB, I got exactly the
same picture (in colour) on that as I did in mono on the 5" TV so I knew the
analogue board and TV were OK.
 
>> luminance line on the connection to the TV board on mine, just
>> red-green-blue with sync and inverse sync which go to the horizontal driver
> 
> Do you mean that the common cathode connection of those diodes goes to
> the monitor connector but nowhere then on the monitor PCB?

No, in trying to trace some of the lines along the bottom of the board I
took the monitor cable off and traced the pins. They are:

1 - 5V
2 - NC
3 - looped to 5
4 - Sync out
5 - looped to 3
6 - emitter of V326 via R336
7 - GREEN
8 - RED
9 - Inverse sync (which also goes via R332 to the base of V333)
10 - BLUE
11 - GND
12 - GND
13 - 12V
14 - 12V
 
>>> Is the MR9735 doing anything? Is it accessing memory, for example?
>>> I still wonder if it has to be initialised (say to vewdata rather than
>>> teletext mode) and if this is not occuring.
>> 
>> Its address and data buses are active as is the pair of 2114s that are
>> acting as a page store. There's a 74LS240 buffering the data bus and that's
>> active.
> 
> OK.. My dislike of 2114s is legendary, but probably not the problem here

They're OK too, surprisingly. I took them off the board and put them in a
PET8032 as video RAM.

>> You could be right though, I'm not convinced the unit is actually running
>> any code yet despite the ROMCS lines working and I can see activity in all
>> 16 RAM chips. Data bus and address bus at CPU and ROM chips looks happy from
> 
> What are the RAMs? If they're more 2114s I wonder if they have problems
> that are confusing the CPU (perhaps corrupting the stack?)

4116-2 wired as 2 banks of 8.

>> a 'doing something' point of view. All the control lines on the CPU are
>> pulsing with the exception of IO/M but if all the IO the chip is doing is to
>> memory then that's to be expected.
> 
> What's the CPU? 8085? I've had those fail in odd ways.

Yeah, 8085A. Thanks to list members I have some spares to try.

>> I've disassembled the ROM code so I'll have a look through that for an init
>> routine, also the datasheet should tell me what its expecting at powerup.
> 
> Personally, I'd stick a logic analyser on it and start tracing the code. See
> if it is executing anything correctly.

I've only got a cheap-ish Saleae compatible 16 channel analyser. Watching
code is a bit above my current level of self-paced learning :)

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: Stripping an RA80

[Tony Duell]

On Sun, Jan 8, 2017 at 6:46 PM, Robert Armstrong  wrote:
>>Tony Duell  wrote:
>>R80 the lines are outputs from the drive giving the coding of the ready lamp 
>>cap
>
> I was always thought that the R80 had to be unit #0 to function, but I admit 
> that I've never tried
> anything else.  I wonder if that's not true??  The RL02 drive(s) on the IDC 
> can be any of units
> 1, 2 or 3.

I don't know about the 11/730's IDC. I was just looking at the R80
schematics, the unit number
lines are output on the 60 wire cable. Maybe the RM80's massbus box
uses them or something?

A quick look at the printset and technical manual suggests that the
11/730 IDC compares the
drive select number from the appropriate output register with the unit
number from the R80 (set
by the ready lamp cap). If they match it uses the R80 logic, if not
then it uses the RL02 logic.
I have no idea if the nomal software will work if the R80 s anything
but unit 0, but it looks like
the hardware was designed to allow for it.


>
>>The HDA is the only major unit I can't repair (yet!).
>
>   Yeah, same here.  In addition to the 11/730 with one (dead) R80, one RA81 
> and one RA82,
>  I have a MicroVAX-III with an RA82 drive.  Keeping them all working has been 
> a real challenge.

The only (other) SDI drive I have is an RA60, and I have no packs for
it. I doubt I will ever use it.

> Fixing the electronics and mechanical parts isn't too bad, and I have plenty 
> of spares, but the

Apart from the ROMs (and those 8355s/8755s are not suported by most
programmers/readers now
available), there are no custom parts on the PCBs that I've spotted.
There are custom chips on
the PCB on the front of the HDA and unlike one Micropolis drive I work
on, you can't replace them
without dismantling the HDA (in a clean room). There are also plug and
socket connectors on that
PCB -- inside the HDA. I hope those don't suffer from bad contacts!

> HDAs don’t seem to be very reliable.  I get the impression that they were 
> designed with a finite
> number of spin up/spin down cycles in mind, and once you exceed that limit 
> they die.  Fortunately

Quite likely. Which means we are less kind to them than we should be
in that we don't keep them
running (or at least I won't)

> I've been able to find spares for the RA81 and RA82 HDAs, but R?80s seem to 
> be pretty rare.

-tony

Re: Stripping an RA80

[Tony Duell]

On Sun, Jan 8, 2017 at 6:20 PM, Robert Armstrong  wrote:
>>Tony Duell  wrote:
>>Well, actually I think you own an R80 but don't know it :-)
>>As I understand it, the R80 had the sort-of SMD interface. 2 cables
>>(60 and 26 wires). It's not SMD, there are significant differences, but 
>>anyway.
>
>   Can't speak for it being an SMD interface, but the rest of this is correct. 
>  And as tony

It's somewhat SMD-like, but it's not SMD. Some of the signals have the
same names
(like the control signal bus from controller to drive being called
'Tag') but you can't
plug an SMD drive into the 11/730 IDC. One oddiity is that the SMD
drive's select
lines are inputs to the drive (as you'd expect), on the R80 the lines
are outputs from
the drive giving the coding of the ready lamp cap (which sets the unit
number like
an RL02). I've not looked into making an interface between the 11/730 IDC and an
SMD drive, I might have to if the R80 proves unrepairable.

> said, the R80 was used only in the VAX-11/730 with the IDC.  The IDC, with 
> the help of
> the CPU microcode, turns the R80 into an MSCP drive and also controls up to 
> three
> RL02 drives at the same time.  FWIW, you can put an R80 HDA in an RA80 drive 
> and
> vice-versa without needing to reformat.  Don't know if that's true for the 
> RM80 - I've never
> actually used one of those.

I've always felt that the RA80 is the 'oddest' member of the family.
As a result I suspect
an RM80 HDA will swap with the others and vice versa, but I've not
tried it. The RM80
manuals aren't on Bitsavers.


>
> I have an 11/730 in the garage with the IDC and R80 drive.  I've got lots of 
> spares for the
> R80 drive itself, but only one HDA and that one is unusable due to too many 
> errors.
> Fortunately I also have a UDA-50 and two more RA8x drives in the machine so 
> it's still
> usable.  It boots just fine from the UDA-50, but I'd love to restore the 
> original drive.

The RA81 and RA82 HDAs seem quite different. They have more heads for
one thing, but
I get the feeling that the servo system is quite different. One manual
suggests not only do
they have the dedicated servo surface, but also embedded servo
information on the data
surfaces. AFAIK the R80, etc only has the dedcated servo surface.

The servo PCB seems to be the same in the R80 and RM80. That for the
RA81 is a lot more
complex with a microprocessor on it.

I had wondered if you could kludge an RA81 or RA82 HDA into an R80, I
think it would be
very hard.


>
>   If anybody has an R?80 HDA that they'd be willing to part with, let me know!

Not only am I the wrong side of the Pond, but the HDA is one part I am
keeping from
the RA80, no matter what I do with the rest of it. I don't know if
it's good, of course, but
if it is it will be kept as a spare for the R80.

The HDA is the only major unit I can't repair (yet!).

-tony

Re: More circuit help required please

[Tony Duell]

On Sun, Jan 8, 2017 at 6:11 PM, Adrian Graham
 wrote:
> On 08/01/2017 17:21, "Tony Duell"  wrote:
>
>>> I photographed both sides of the board and merged the pictures together to
>>> make a front/back composite. The trace for the cathodes of the 3 diodes
>>> links together on the back of the board and doesn't go anywhere else. The
>>> front trace from V302 cathode goes straight to R312. The anodes DO link with
>>> the monitor driver board through the connection marked MON though.
>>
>> OK, probably some kind of luminance signal. Was there ever a monochrome
>> version of this unit?
>
> The whole unit is monochrome, it only has a little 5" B TV as its output
> device -

OK, was there ever a colour version :-)

>
> http://www.binarydinosaurs.co.uk/STCExecutel01.jpg
>
> However, two of us bought units at the same time and the other one has a
> little bridgeboard containing a 74LS244 that sends the RGB signals to a DIN
> socket on the back of the case for an external monitor. I also can't see a

And in a sense there was...

> luminance line on the connection to the TV board on mine, just
> red-green-blue with sync and inverse sync which go to the horizontal driver

Do you mean that the common cathode connection of those diodes goes to
the monitor connector but nowhere then on the monitor PCB?

>> Is the MR9735 doing anything? Is it accessing memory, for example?
>> I still wonder if it has to be initialised (say to vewdata rather than
>> teletext mode) and if this is not occuring.
>
> Its address and data buses are active as is the pair of 2114s that are
> acting as a page store. There's a 74LS240 buffering the data bus and that's
> active.

OK.. My dislike of 2114s is legendary, but probably not the problem here

>
> You could be right though, I'm not convinced the unit is actually running
> any code yet despite the ROMCS lines working and I can see activity in all
> 16 RAM chips. Data bus and address bus at CPU and ROM chips looks happy from

What are the RAMs? If they're more 2114s I wonder if they have problems
that are confusing the CPU (perhaps corrupting the stack?)


> a 'doing something' point of view. All the control lines on the CPU are
> pulsing with the exception of IO/M but if all the IO the chip is doing is to
> memory then that's to be expected.

What's the CPU? 8085? I've had those fail in odd ways.

>
> I've disassembled the ROM code so I'll have a look through that for an init
> routine, also the datasheet should tell me what its expecting at powerup.

Personally, I'd stick a logic analyser on it and start tracing the code. See
if it is executing anything correctly.

-tony

Re: More circuit help required please

[Adrian Graham]

On 08/01/2017 17:21, "Tony Duell"  wrote:

>> I photographed both sides of the board and merged the pictures together to
>> make a front/back composite. The trace for the cathodes of the 3 diodes
>> links together on the back of the board and doesn't go anywhere else. The
>> front trace from V302 cathode goes straight to R312. The anodes DO link with
>> the monitor driver board through the connection marked MON though.
> 
> OK, probably some kind of luminance signal. Was there ever a monochrome
> version of this unit?

The whole unit is monochrome, it only has a little 5" B TV as its output
device - 

http://www.binarydinosaurs.co.uk/STCExecutel01.jpg

However, two of us bought units at the same time and the other one has a
little bridgeboard containing a 74LS244 that sends the RGB signals to a DIN
socket on the back of the case for an external monitor. I also can't see a
luminance line on the connection to the TV board on mine, just
red-green-blue with sync and inverse sync which go to the horizontal driver
chip and vertical driver chip respectively. You may remember I was asking
questions about these chips a couple of months ago because that TV board
suffered some component rot and I thought the wavy picture was because of
that.

>> One of the reasons I'm asking these questions is I'm trying to see if
>> there's another source of composite sync given that the MR9735 itself
>> doesn't do it, even though it should.
> 
> I doubt it Why would there be?

Clutching at straws :)
 
> Is the MR9735 doing anything? Is it accessing memory, for example?
> I still wonder if it has to be initialised (say to vewdata rather than
> teletext mode) and if this is not occuring.

Its address and data buses are active as is the pair of 2114s that are
acting as a page store. There's a 74LS240 buffering the data bus and that's
active. 

You could be right though, I'm not convinced the unit is actually running
any code yet despite the ROMCS lines working and I can see activity in all
16 RAM chips. Data bus and address bus at CPU and ROM chips looks happy from
a 'doing something' point of view. All the control lines on the CPU are
pulsing with the exception of IO/M but if all the IO the chip is doing is to
memory then that's to be expected.

I've disassembled the ROM code so I'll have a look through that for an init
routine, also the datasheet should tell me what its expecting at powerup.

Cheers,

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: More circuit help required please

[Tony Duell]

> I photographed both sides of the board and merged the pictures together to
> make a front/back composite. The trace for the cathodes of the 3 diodes
> links together on the back of the board and doesn't go anywhere else. The
> front trace from V302 cathode goes straight to R312. The anodes DO link with
> the monitor driver board through the connection marked MON though.

OK, probably some kind of luminance signal. Was there ever a monochrome
version of this unit?


> One of the reasons I'm asking these questions is I'm trying to see if
> there's another source of composite sync given that the MR9735 itself
> doesn't do it, even though it should.

I doubt it Why would there be?

Is the MR9735 doing anything? Is it accessing memory, for example?
I still wonder if it has to be initialised (say to vewdata rather than teletext
mode) and if this is not occuring.

-tony

Re: More circuit help required please

[Adrian Graham]

On 08/01/2017 16:18, "Mouse"  wrote:

 http://www.binarydinosaurs.co.uk/STCExecutelSyncCircuit.jpg
>>> I don't believe it's correct as drawn.  For one thing you have V333,
>>> an NPN transistor, with the collector grounded (and no -ve supplies
>>> on the circuit.
> 
> Bipolar transistors are to some extent symmetric under interchange of
> collector and emitter.  Simplified pictures showing a bar of
> semiconductor with the ends being emitter and collector and a thin base
> layer in the middle are, well, simplified, but there is _some_ truth
> lurking in them.
> 
> However, the only reason I could see that being done deliberately is if
> the circuit is analog and the transistor's behaviour is relevantly
> different from the normal way around.  This circuit doesn't look like
> that to me.  Redrawing it a bit less confusingly with V333 E/C swapped
> makes it look as though V333 and V326 are being used in their switching
> regions, not their linear regions.

Yes, I got the emitter and collector swapped. The software I'm using
(Fritzing) is excellent given it costs nothing, but occasionally you can
make a change then alter something else in the properties of the item and
the change is lost.
 
> The lack of negative supplies is hardly conclusivein itself; negative
> voltages could be developed in any of many ways.  However, V325, R322,
> and V326 would make it difficult for the R335/V325/V333 junction point
> to get too far below 5V (admittedly this is much less true if R322's
> value is actually significantly higher).
> 
> I also question the way R311/R310/R309 are all different.  I would
> expect the red, green, and blue circuits to be electrically more or
> less identical, and different pulldown values does not fit with that.

There's been a couple of resistor failures with this board so I'm at the
stage of starting with a DMM, swapping probes to hopefully get a consistent
reading then reading the bands and using the calculator here for ones I
don't instantly recognise:

http://www.allaboutcircuits.com/tools/resistor-color-code-calculator/

If the two don't match I take it out of circuit.

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: More circuit help required please

[Adrian Graham]

On 08/01/2017 14:06, "Tony Duell"  wrote:

> On Sun, Jan 8, 2017 at 2:00 PM, Adrian Graham
>  wrote:
> 
>> You were right, I'd drawn out R335 wrongly and flipped V333. All the anodes
>> go via R312 to the collector of V333 along with R309-R311. Base for V333 is
>> the inverted sync output of the MR9735. R322 is 6.8k
>> (blue-grey-black-brown). All diodes are 1N4148.
>> 
>> http://www.binarydinosaurs.co.uk/STCExecutelSyncCircuit2.jpg
> 
> That makes more sense. I am surprised that the anodes of the diodes don't go
> to a +ve power line (maybe +12V), though. It could be right as drawn,
> but I would check it.

I photographed both sides of the board and merged the pictures together to
make a front/back composite. The trace for the cathodes of the 3 diodes
links together on the back of the board and doesn't go anywhere else. The
front trace from V302 cathode goes straight to R312. The anodes DO link with
the monitor driver board through the connection marked MON though.

> When you power up, what voltage and/or signal (use a 'scope) do you see on the
> anodes of said diodes?

Looks to be 4V on all 3 lines for RGB:

http://www.binarydinosaurs.co.uk/STCExecutelRGBsignal.jpg

One of the reasons I'm asking these questions is I'm trying to see if
there's another source of composite sync given that the MR9735 itself
doesn't do it, even though it should.

Cheers!

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: More circuit help required please

[Tony Duell]

On Sun, Jan 8, 2017 at 4:18 PM, Mouse  wrote:

> I also question the way R311/R310/R309 are all different.  I would
> expect the red, green, and blue circuits to be electrically more or
> less identical, and different pulldown values does not fit with that.

Well, I wonder if it's producing a weighted sum of R,G,B to make a
monochrome luminance signal. Not at all uncommon.


-tony

Re: More circuit help required please

[Mouse]

>>> http://www.binarydinosaurs.co.uk/STCExecutelSyncCircuit.jpg
>> I don't believe it's correct as drawn.  For one thing you have V333,
>> an NPN transistor, with the collector grounded (and no -ve supplies
>> on the circuit.

Bipolar transistors are to some extent symmetric under interchange of
collector and emitter.  Simplified pictures showing a bar of
semiconductor with the ends being emitter and collector and a thin base
layer in the middle are, well, simplified, but there is _some_ truth
lurking in them.

However, the only reason I could see that being done deliberately is if
the circuit is analog and the transistor's behaviour is relevantly
different from the normal way around.  This circuit doesn't look like
that to me.  Redrawing it a bit less confusingly with V333 E/C swapped
makes it look as though V333 and V326 are being used in their switching
regions, not their linear regions.

The lack of negative supplies is hardly conclusivein itself; negative
voltages could be developed in any of many ways.  However, V325, R322,
and V326 would make it difficult for the R335/V325/V333 junction point
to get too far below 5V (admittedly this is much less true if R322's
value is actually significantly higher).

I also question the way R311/R310/R309 are all different.  I would
expect the red, green, and blue circuits to be electrically more or
less identical, and different pulldown values does not fit with that.

>> For another, R322 is ridiculously low.

Indeed.

I don't know how much you know about electronics at the relevant level,
so it's possible what I'm about to say is unnecessary or has already
been considered.

Did these resistor values come from reading bands, or measuring
in-circuit, or what?  Note that R322 is in parallel with the C-B diode
of V326; a simple ohmmeter put across it may end up measuring the diode
drop instead.  (To test this theory, switch ranges.  A diode drop will
usually give you approximately the same digits in each range - eg, 6.7
ohms on the 0-10 range, 67 ohms on the 0-100 one, 670 ohms for the 0-1K
range, etc.  Also, swapping the probe leads will give a different
reading if that's what's behind this.)

>> And I would expect the anodes of the 3 diodes on the RGB outputs to
>> go somewhere other than a resistor to ground.

At least with R312 as high as 10K.  If it were much lower, the diodes
could be clipping diodes; a diode drop is not too far from about the
right swing for a video signal.

/~\ The ASCII Mouse
\ / Ribbon Campaign
 X  Against HTMLmo...@rodents-montreal.org
/ \ Email!   7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B

Sunday brain tickler

[Chuck Guzis]

I'm looking at a sample of what I see as a directory of sorts and am
attempting to decode the file names from it.  They're not anything as
elegant as Rad50, but the encoding has escaped my weary brain.

The system in question is a Lanier 103 word processor.

Here are some samples.  Can anyone come up with the encoding scheme?  It
can't be very complex as this was a comparatively brain-dead system:

(All values in hex)

c4 a3 75 6a ab 52 00 00
5c 25 15 1b 4c 40 00 00
cd 6d 15 7a a6 10 cb 82
a1 7a c1 c0 00 00 00 00
94 2f 38 40 00 00 00 00
d0 7f 9f 12 25 fd 53 28

The recurrence of these strings in what appears to be a block directory
in the same position tell me that they must be file names.   The file
data itself is in ASCII, more or less (special formatting codes).  The
distribution of values to me suggests some sort of bit-packing algorithm
is involved.

Thanks for any suggestions.

--Chuck

Re: Drum Computers

[Chuck Guzis]

On 01/08/2017 03:02 AM, Mark Linimon wrote:

> - One time a contractor came in to paint the building and despite 
> instructions, painted the computer room as well.  Of course the paint
> got in to the Bryant.  The folks who worked on it said, well, what
> have we got to lose.  They pulled the platters, used some kind of
> solvent to remove the mess, put them back in, and the thing just
> continued to work.  "Tolerances", who needs 'em ...


I had a couple of the salvaged Bryant platters as mementos back in the
day.  I thought about making a coffee table out of one, but the hole in
the middle was a stopper for me.   Perhaps I should have stuck a
flowerpot in it or something...

As I recall the heads on the Bryant weighed in at about 8 lbs apiece.

--Chuck

Re: Drum Computers

[Mark Linimon]

On Sat, Jan 07, 2017 at 04:26:25PM -0800, Chuck Guzis wrote:
> I'm sure that Paul remembers the CDC 6603 disk drive, made by Bryant
> (the big horizontal spindle one with the hydraulic "leak collectors").

I didn't see the Bryant that Rice University had in operation on the
R1 Research Computer; I was one year too late for that.  They did save
one of the platters for laughs.  I recall it being about as wide as my
outstretched arms.

I was told two tales about the Bryant:

 - They had it up on the second floor.  When the Bryant would seek,
   the building would "counter-seek".

 - One time a contractor came in to paint the building and despite
   instructions, painted the computer room as well.  Of course the
   paint got in to the Bryant.  The folks who worked on it said,
   well, what have we got to lose.  They pulled the platters, used
   some kind of solvent to remove the mess, put them back in, and
   the thing just continued to work.  "Tolerances", who needs 'em ...

mcl

Re: More circuit help required please

[Tony Duell]

On Sun, Jan 8, 2017 at 2:00 PM, Adrian Graham
 wrote:

> You were right, I'd drawn out R335 wrongly and flipped V333. All the anodes
> go via R312 to the collector of V333 along with R309-R311. Base for V333 is
> the inverted sync output of the MR9735. R322 is 6.8k
> (blue-grey-black-brown). All diodes are 1N4148.
>
> http://www.binarydinosaurs.co.uk/STCExecutelSyncCircuit2.jpg

That makes more sense. I am surprised that the anodes of the diodes don't go
to a +ve power line (maybe +12V), though. It could be right as drawn,
but I would
check it.

When you power up, what voltage and/or signal (use a 'scope) do you see on the
anodes of said diodes?

-tony

Re: More circuit help required please

[Adrian Graham]

On 08/01/2017 07:31, "Tony Duell"  wrote:

> On Sat, Jan 7, 2017 at 11:37 PM, Adrian Graham
>  wrote:
>> Evening all,
>> 
>> I wish I had the ability to take a board layout and turn it into a logically
>> laid out schematic but as yet I don't. Video sync on my Executel 3910 is
>> still running me round in circles so could one of you fine folk take a look
>> at this board layout drawn as best I can:
>> 
>> http://www.binarydinosaurs.co.uk/STCExecutelSyncCircuit.jpg
>> 
>> ...and let me know what it does please? The chip on the left is a Plessey
> 
> 
> I don't believe it's correct as drawn. For one thing you have V333, an NPN
> transistor, with the collector grounded (and no -ve supplies on the circuit.
> For
> another, R322 is ridiculously low. And I would expect the anodes of the
> 3 diodes on the RGB outputs to go somewhere other than a resistor to
> ground.

You were right, I'd drawn out R335 wrongly and flipped V333. All the anodes
go via R312 to the collector of V333 along with R309-R311. Base for V333 is
the inverted sync output of the MR9735. R322 is 6.8k
(blue-grey-black-brown). All diodes are 1N4148.

http://www.binarydinosaurs.co.uk/STCExecutelSyncCircuit2.jpg

Thanks for looking!

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: More circuit help required please

[Adrian Graham]

On 08/01/2017 07:31, "Tony Duell"  wrote:

> On Sat, Jan 7, 2017 at 11:37 PM, Adrian Graham
>  wrote:
>> Evening all,
>> 
>> I wish I had the ability to take a board layout and turn it into a logically
>> laid out schematic but as yet I don't. Video sync on my Executel 3910 is
>> still running me round in circles so could one of you fine folk take a look
>> at this board layout drawn as best I can:
>> 
>> http://www.binarydinosaurs.co.uk/STCExecutelSyncCircuit.jpg
>> 
>> ...and let me know what it does please? The chip on the left is a Plessey
> 
> 
> I don't believe it's correct as drawn. For one thing you have V333, an NPN
> transistor, with the collector grounded (and no -ve supplies on the circuit.
> For
> another, R322 is ridiculously low. And I would expect the anodes of the
> 3 diodes on the RGB outputs to go somewhere other than a resistor to
> ground.

Hm, ok, that's today's task then. For V333 it could be that I just have the
pin numbers reversed but I'll double check. The diodes bothered me too and
I'm trying to think of a better way of tracing unknown lines on the bottom
of the board. My sponge-wrapped-in-tin-foil method isn't infallible.

Cheers!

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Vintage computers for sale

[Sellam Ismail]

Hey, I saw your message to the ClassicCmp making list. I believe I have a
KIM-1 to sell you but I'd have to dig it out.  Also, most of the machines
mentioned in this posting are still available:

http://www.vcfed.org/forum/showthread.php?51781-Mulitple-and-divers-computers-for-sale

Let me know if anything I have interests you. Thanks!

Sellam

Re: Drum Computers

[Chuck Guzis]

On 01/07/2017 08:44 AM, Paul Koning wrote:

> Not a drum computer but another example of a company not known for
> computers that nevertheless built one: Goodyear.  A supercomputer
> called STARAN, a very odd architecture.  Actually based on an earlier
> one built at Sanders Associates (a defense contractor) invented by a
> friend of ours, William Shooman.

I'm sure that Paul remembers the CDC 6603 disk drive, made by Bryant
(the big horizontal spindle one with the hydraulic "leak collectors").
Bryant Computer Products started out as the Bryant Chucking Grinder
Company.  Later, it was acquired by Ex-cell-o, the people who made milk
cartons.

I've witnessed someone slip and fall in a pool of Pydraul from a leaking
Bryant 4000.

They don't build 'em like that, thank heavens.

--Chuck

Re: Drum Computers

[Paul Berger]

On 2017-01-07 8:26 PM, Chuck Guzis wrote:

On 01/07/2017 08:44 AM, Paul Koning wrote:


Not a drum computer but another example of a company not known for
computers that nevertheless built one: Goodyear.  A supercomputer
called STARAN, a very odd architecture.  Actually based on an earlier
one built at Sanders Associates (a defense contractor) invented by a
friend of ours, William Shooman.

I'm sure that Paul remembers the CDC 6603 disk drive, made by Bryant
(the big horizontal spindle one with the hydraulic "leak collectors").
Bryant Computer Products started out as the Bryant Chucking Grinder
Company.  Later, it was acquired by Ex-cell-o, the people who made milk
cartons.

I've witnessed someone slip and fall in a pool of Pydraul from a leaking
Bryant 4000.

They don't build 'em like that, thank heavens.

--Chuck
Some of the early IBM disk drives used hydraulic actuators as well, and 
the 1403 used hydraulics to move the paper.


I recall working on a high volume laser page printer that used an oil 
fuser, one of the rolls in the fuser dipped into a trough filled with 
silicon oil.  The oil was fed by a plastic bottle with a regulator valve 
in the cap that was inverted in the end of the trough.   Unfortunately 
the oil bottle was badly designed, and the cap would contact the body of 
the bottle before the threads bottomed out and you could pretty easily 
crack the neck where if joined the bottle if you where not careful.  
With the neck cracked all the oil would leak out and it made a huge mess 
inside the printer, but an even bigger problem was if it leaked out onto 
a raised floor it made the floor tiles extremely slick and it was very 
hard to clean off the tiles.


Paul.