Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Pontus Pihlgren via cctalk]

Hi again

Olafs also found this:
http://www.nedopc.org/forum/viewtopic.php?t=9778

Unless you know russian, maybe you can use google translate.

Regards,
Pontus.

On Tue, Jan 08, 2019 at 11:06:12AM +0100, Pontus Pihlgren via cctalk 
wrote:
> Hi Iain
> 
> I asked a guy from Latvia that I know, Olafs. He recognized the 
> transistors as KT315 A and B. Collector is middle pin.
> 
> https://en.wikipedia.org/wiki/KT315
> 
> He might also be able to help with spare lights, contact me off-list. 
> Unfortunately he has no documentation.
> 
> /P
> 
> On Sat, Jan 05, 2019 at 06:36:56PM +, Dr Iain Maoileoin via cctalk 
> wrote:
> > Off topic, but looking for help and/or wisdom.
> > 
> > If you visit https://www.scotnet.co.uk/iain/saratov 
> > /  
> > you will see some photos and wire-lists of work that I have started on the 
> > front panel of a Capatob 2.
> > 
> > I plan to get the switches and lights running on a blinkenbone board with a 
> > PDP8 emulation behind it.  (I already have an PDP11/70 front-panel running 
> > on the same infrastructure)
> > 
> > I have been struggling for over a year to get much info about this saratov 
> > computer (circuit diagrams etc).  So I have started the reverse engineering 
> > on the panel.
> > 
> > Does anybody know anything about this computer?  online or offline it would 
> > be much appreciated.
> > 
> > Iain

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Pontus Pihlgren via cctalk]

Hi Iain

I asked a guy from Latvia that I know, Olafs. He recognized the 
transistors as KT315 A and B. Collector is middle pin.

https://en.wikipedia.org/wiki/KT315

He might also be able to help with spare lights, contact me off-list. 
Unfortunately he has no documentation.

/P

On Sat, Jan 05, 2019 at 06:36:56PM +, Dr Iain Maoileoin via cctalk 
wrote:
> Off topic, but looking for help and/or wisdom.
> 
> If you visit https://www.scotnet.co.uk/iain/saratov 
> /  
> you will see some photos and wire-lists of work that I have started on the 
> front panel of a Capatob 2.
> 
> I plan to get the switches and lights running on a blinkenbone board with a 
> PDP8 emulation behind it.  (I already have an PDP11/70 front-panel running on 
> the same infrastructure)
> 
> I have been struggling for over a year to get much info about this saratov 
> computer (circuit diagrams etc).  So I have started the reverse engineering 
> on the panel.
> 
> Does anybody know anything about this computer?  online or offline it would 
> be much appreciated.
> 
> Iain

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Kyle Owen via cctalk]

On Mon, Jan 7, 2019 at 8:51 AM Peter Corlett via cctalk <
cctalk@classiccmp.org> wrote:

> Thanks to inflation, $0.25 in 1972 is worth $1.51 now. Likewise, $1.25 has
> inflated to $7.54. So they're cheaper in real terms than they used to be.
>
> However, it's still not entirely comparable, as I suspect nobody's making
> 74-series chips any more so you're buying NOS. A modern equivalent would
> be a
> microcontroller, which start at well under a dollar.
>

Logic chips still have their uses, and are most certainly still being made.
You can still get 74LS parts, in a DIP package even:
https://www.digikey.com/product-detail/en/texas-instruments/SN74LS00N/296-1626-5-ND/277272

Note: it's an active production part, too.

Kyle

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Peter Corlett via cctalk]

On Sun, Jan 06, 2019 at 02:54:08PM -0700, ben via cctalk wrote:
> On 1/6/2019 12:24 PM, allison via cctalk wrote:
>> The small beauty of being there...   FYI back then (1972) a 7400 was about
>> 25 cents and 7483 adder was maybe $1.25.  Least that's what I paid.
> Checks my favorite supplier.
> $1.25 for 7400 and $4.00 for a 7483.
> It has gone up in price.

Thanks to inflation, $0.25 in 1972 is worth $1.51 now. Likewise, $1.25 has
inflated to $7.54. So they're cheaper in real terms than they used to be.

However, it's still not entirely comparable, as I suspect nobody's making
74-series chips any more so you're buying NOS. A modern equivalent would be a
microcontroller, which start at well under a dollar.

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[William Donzelli via cctalk]

> - some marketing person made it up

You believed them? Have your head examined.

> - they were only counting things that were general-purpose (i.e. came with
>   mass storage and compilers)

Conditions, conditions.

> - they didn't consider micros as "computers" (many were used in things like
>   printers, etc, and were not usable as general-purpose computers)

Well, that is DECish, ignoring the coming tsunami of micros. Wow, did
they pay the price...

--
Will

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Noel Chiappa via cctalk]

> From: William Donzelli

>> in 1980, there were more PDP-11's, world-wide, than any other kind of
>> computer.

> I bet the guys at Zilog might have something to talk to you about.

I was quoting my memory of a DEC ad in the WSJ, which now that I go check,
says the -11 was "the best-selling computer in the world" (the ad was in
1980). There are a number of possible explanations as to why it makes this
claim:

- some marketing person made it up
- they were only counting things that were general-purpose (i.e. came with
  mass storage and compilers)
- they didn't consider micros as "computers" (many were used in things like
  printers, etc, and were not usable as general-purpose computers)

Etc, etc.

 Noel

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[ben via cctalk]

On 1/6/2019 12:24 PM, allison via cctalk wrote:


The small beauty of being there...   FYI back then (1972) a 7400 was
about 25 cents
and 7483 adder was maybe $1.25.  Least that's what I paid.

Checks my favorite supplier.

$1.25 for 7400 and $4.00 for a 7483.
It has gone up in price.

Allison


Ben.

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[allison via cctalk]

On 01/06/2019 01:54 PM, William Donzelli via cctalk wrote:
>> And then the PDP-11 put the nail in that coffin (and in 1980, there were more
>> PDP-11's, world-wide, than any other kind of computer).
> I bet the guys at Zilog might have something to talk to you about.
>
> --
> Will
And Intel!  8008 and 8080 was a byte machine as was 8085, z80,  8088,
6800, 6502, and a long list to follow.

The PDP-11 was unique that it was 8/16 bit in that memory (and by
default IO) supported both byte and word
reads and write.   Instructions were 16bit but data was byte word.  

There were more  Z80 based machines (TRS-80 alone exceeded 250,000) than
PDP-11.
History guys, we are about history!

Allison

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[allison via cctalk]

On 01/06/2019 02:08 PM, Grant Taylor via cctalk wrote:
> On 1/6/19 11:25 AM, Guy Sotomayor Jr via cctalk wrote:
>> I think it’s also telling that the IETF uses the term octet in all of
>> the specifications to refer to 8-bit sized data.  As “byte” (from
>> older machines) could be anything and is thus somewhat ambiguous.
>>
>> It *may* have been the IBM 360 that started the trend of Byte ==
>> 8-bits as the 360’s memory (in IBM’s terms) was byte addressable and
>> the instructions for accessing them were “byte” instructions (as
>> opposed to half-word and word instructions).
>
Yes it was.

Machines around them and in that time frame (mainframe) were 12, 18, 36,
60 bit words.

The big break was mid 1970s with micros first 8008, 8080, 6800 and
bigger machines
like PDP11 (did byte word reads and writes) and TI990.

The emergence of VAX and other 32bit machines made 8bit common as
terminal IO was
starting to standardize.

> Thank you for the clarification.
>
> My take away is that before some nebulous point in time (circa IBM's
> 360) a "byte" could be a number of different bits, depending on the
> computer being discussed.  Conversely, after said nebulous point in
> time a byte was standardized on 8-bits.
>
> Is that fair and accurate enough?  -  I'm wanting to validate the
> patch before I apply it to my mental model of things.  ;- 

There is no hard before and after as systems like DEC10 and other
persisted for a while.  Also part of it was IO codes for the
EBDIC, Flexowriter, ASr33 (8level vs Baudot), and CRT terminals emerging
with mostly IBM or ANSI.

I am somewhat DEC and personal computer (pre IBM PC) centric on this as
they were he machines I got to see
and work with that were not in rooms with glass and white coated
specialists.

Allison

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[allison via cctalk]

On 01/06/2019 01:19 PM, Noel Chiappa via cctalk wrote:
> > From: Grant Taylor
>
> > Is "byte" the correct term for 6-bits?  I thought a "byte" had always 
> > been 8-bits.
>
> I don't claim wide familiary with architectural jargon from the early days,
> but the PDP-10 at least (I don't know about other prominent 36-bit machines
> such as the IBM 7094/etc, and the GE 635/645) supported 'bytes' of any size,
> with 'byte pointers' used in a couple of instructions which could extract and
> deposit 'bytes' from a word; the pointers specified the starting bit, and the
> width of the 'byte'. These were used for both SIXBIT (an early character
> encoding), and ASCII (7-bit bytes, 5 per word, with one bit left over).
As far as what other systems supported especially the 7094 and GE, that
is already out
of context as the focus was a Russian PDP-8 clone.  Any other machines
are then thread
contamination or worse.

In the early days a byte was the smallest recognized group of bits for
that system
and in some case its 9 bits, 6bits as they were even divisible segments
of the machine
word.  This feature was the bane of programmers as everyone had a
different idea
of what it was and it was poison to portability.

For PDP-8 and friends it was 6 bits and was basically a halfword, also
used as stated for
6bit subset of ASCII (uppercase, TTY codes).  Most of the 8 series had
the bit mapped
instructions (DEC called the microcoded) for doing BSW, byte swap,  swap
the
lower half of the ACC with the upper half.  Very handy for doing
character IO.

> > I would have blindly substituted "word" in place of "byte" except for
> > the fact that you subsequently say "12-bit words". I don't know if
> > "words" is parallel on purpose, as in representing a quantity of two
> > 6-bit word.
>
> I think 'word' was usually used to describe the instruction size (although
> some machines also supported 'half-word' instructions), and also the
> machine's 'ordinary' length - e.g. for the accumulator(s), the quantum of
> data transfer to/from memory, etc. Not necessarily memory addresses, mind -
> on the PDP-10, those were 18 bits (i.e. half-word) - although the smallest
> thing _named_ by a memory addresses was usually a word.
>
>   Noel
The PDP-8 and 12bit relations the instruction word and basic
architecture was 12bit word.
There were no instructions that were a half word in length or other
fragmentations.  The
machine was fairly simple and all the speculated concepts were well
outside the design
of the PDP-5/8 family.   For all of those the instruction fetch, memory
reads and write
were always words of 12bits.   I'd expect a Russian PDP-8 clone to be
the same.   After
all DEC did widely gave out the data books with nearly everything but
schematics.  The
value of copying is software is also copied.  It happened here with the
DCC-112 a
PDP-8e functional clone.

While its possible to use half word ram with reconstruction the hardware
cost is high
(registers to store the pieces) and it would take more to do that than
whole 12bit words.
Any time you look at old machine especially pre-IC registers were costly
and only done
as necessity dictated as a single bit flipflop was likely 4 transistors
(plus diodes and other
components) or more to implement never minding gating. 

Minor history and thread relative drift... 
The only reason people didn't build their own PDP-8 in the early 70s was
CORE.  It was
the one part a early personal computer (meaning personally owned then) 
was difficulty
to duplicate and expensive outright buy.  Trying to make "random" core
planes that
were available work was very difficult due to lack of data, critical
timing, and the
often minimal bench (and costly) test equipment.   The minimum gear for
seeing
the timing was a Tek-516 and that was $1169(1969$).   Semiconductor ram was
either a few bits (4x4) or 1101 (three voltage 256x1) at about 8$ in
1972 dollars.  That
made the parts for a 256x12 a weeks pay at that time (pre-8008) and a
4Kx12 with parts
was nearly that of a new truck (2100$)!.   Compared the basic logic of
the 8e (only
three boards of SSI TTL) core/ram was the show stopper.  About 7 years
later a 8K8
S100 ram was about  (early 1979) 100$, by 1980 64kx8 was 100$.   Moore's
law was
being felt.

The small beauty of being there...   FYI back then (1972) a 7400 was
about 25 cents
and 7483 adder was maybe $1.25.  Least that's what I paid.

Allison

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Grant Taylor via cctalk]

On 1/6/19 11:25 AM, Guy Sotomayor Jr via cctalk wrote:
I think it’s also telling that the IETF uses the term octet in all of 
the specifications to refer to 8-bit sized data.  As “byte” (from 
older machines) could be anything and is thus somewhat ambiguous.


It *may* have been the IBM 360 that started the trend of Byte == 8-bits 
as the 360’s memory (in IBM’s terms) was byte addressable and the 
instructions for accessing them were “byte” instructions (as opposed 
to half-word and word instructions).


Thank you for the clarification.

My take away is that before some nebulous point in time (circa IBM's 
360) a "byte" could be a number of different bits, depending on the 
computer being discussed.  Conversely, after said nebulous point in time 
a byte was standardized on 8-bits.


Is that fair and accurate enough?  -  I'm wanting to validate the patch 
before I apply it to my mental model of things.  ;-)




--
Grant. . . .
unix || die

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[William Donzelli via cctalk]

> And then the PDP-11 put the nail in that coffin (and in 1980, there were more
> PDP-11's, world-wide, than any other kind of computer).

I bet the guys at Zilog might have something to talk to you about.

--
Will

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Noel Chiappa via cctalk]

> From: Guy Sotomayor Jr

> I think it's also telling that the IETF uses the term octet in all of
> the specifications to refer to 8-bit sized data.

Yes; at the time the TCP/IP specs were done, PDP-10's were still probably the
most numerous machines on the 'net, so we were careful to use 'octet'.

Although the writing was clearly on the wall, which is why it's all in octets,
with no support for other-length words (unlike the ARPANET, which sort of
supported word lengths which were not a multiple of 8 or 16 - which was
actually use to transfer binary data between 36-bit machines).

> It *may* have been the IBM 360 that started the trend of Byte =
> 8-bits

Yup.

And then the PDP-11 put the nail in that coffin (and in 1980, there were more
PDP-11's, world-wide, than any other kind of computer).

 Noel

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Guy Sotomayor Jr via cctalk]

I think it’s also telling that the IETF uses the term octet in all of the 
specifications to
refer to 8-bit sized data.  As “byte” (from older machines) could be anything 
and is
thus somewhat ambiguous.

It *may* have been the IBM 360 that started the trend of Byte == 8-bits as the 
360’s
memory (in IBM’s terms) was byte addressable and the instructions for accessing
them were “byte” instructions (as opposed to half-word and word instructions).

TTFN - Guy

> On Jan 6, 2019, at 10:19 AM, Noel Chiappa via cctalk  
> wrote:
> 
>> From: Grant Taylor
> 
>> Is "byte" the correct term for 6-bits?  I thought a "byte" had always 
>> been 8-bits.
> 
> I don't claim wide familiary with architectural jargon from the early days,
> but the PDP-10 at least (I don't know about other prominent 36-bit machines
> such as the IBM 7094/etc, and the GE 635/645) supported 'bytes' of any size,
> with 'byte pointers' used in a couple of instructions which could extract and
> deposit 'bytes' from a word; the pointers specified the starting bit, and the
> width of the 'byte'. These were used for both SIXBIT (an early character
> encoding), and ASCII (7-bit bytes, 5 per word, with one bit left over).
> 
>> I would have blindly substituted "word" in place of "byte" except for
>> the fact that you subsequently say "12-bit words". I don't know if
>> "words" is parallel on purpose, as in representing a quantity of two
>> 6-bit word.
> 
> I think 'word' was usually used to describe the instruction size (although
> some machines also supported 'half-word' instructions), and also the
> machine's 'ordinary' length - e.g. for the accumulator(s), the quantum of
> data transfer to/from memory, etc. Not necessarily memory addresses, mind -
> on the PDP-10, those were 18 bits (i.e. half-word) - although the smallest
> thing _named_ by a memory addresses was usually a word.
> 
>   Noel

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Noel Chiappa via cctalk]

> From: Grant Taylor

> Is "byte" the correct term for 6-bits?  I thought a "byte" had always 
> been 8-bits.

I don't claim wide familiary with architectural jargon from the early days,
but the PDP-10 at least (I don't know about other prominent 36-bit machines
such as the IBM 7094/etc, and the GE 635/645) supported 'bytes' of any size,
with 'byte pointers' used in a couple of instructions which could extract and
deposit 'bytes' from a word; the pointers specified the starting bit, and the
width of the 'byte'. These were used for both SIXBIT (an early character
encoding), and ASCII (7-bit bytes, 5 per word, with one bit left over).

> I would have blindly substituted "word" in place of "byte" except for
> the fact that you subsequently say "12-bit words". I don't know if
> "words" is parallel on purpose, as in representing a quantity of two
> 6-bit word.

I think 'word' was usually used to describe the instruction size (although
some machines also supported 'half-word' instructions), and also the
machine's 'ordinary' length - e.g. for the accumulator(s), the quantum of
data transfer to/from memory, etc. Not necessarily memory addresses, mind -
on the PDP-10, those were 18 bits (i.e. half-word) - although the smallest
thing _named_ by a memory addresses was usually a word.

Noel

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Grant Taylor via cctalk]

On 1/6/19 7:08 AM, Bob Smith via cctalk wrote:
What is called the 8 is really based on the 5, used 6-bit bytes, 12 bit 
words, and was Octal based


Is "byte" the correct term for 6-bits?  I thought a "byte" had always 
been 8-bits.  But I started paying attention in the '90s, so I missed a lot.


I would have blindly substituted "word" in place of "byte" except for 
the fact that you subsequently say "12-bit words".  I don't know if 
"words" is parallel on purpose, as in representing a quantity of two 
6-bit word.


Will someone please explain what I'm missing that transpired before I 
started paying attention in the '90s?




--
Grant. . . .
unix || die

Re: off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Bob Smith via cctalk]

https://hapoc2015.sciencesconf.org/file/176702

gives a Little more history on Soviet copies of computers.
The timing of the production of the Capatob 2 seems to make it a
PDP8/L clone, not an M. What is called the 8 is really based on the 5,
used 6-bit bytes, 12 bit words, and was Octal based - memory was the
most expensive part of the system at least through the early 70s, and
thus 12 bit words for double precision, 24bits, was a reasonable
approach for a scientific computer.
bb

On Sat, Jan 5, 2019 at 1:37 PM Dr Iain Maoileoin via cctalk
 wrote:
>
> Off topic, but looking for help and/or wisdom.
>
> If you visit https://www.scotnet.co.uk/iain/saratov 
> /  
> you will see some photos and wire-lists of work that I have started on the 
> front panel of a Capatob 2.
>
> I plan to get the switches and lights running on a blinkenbone board with a 
> PDP8 emulation behind it.  (I already have an PDP11/70 front-panel running on 
> the same infrastructure)
>
> I have been struggling for over a year to get much info about this saratov 
> computer (circuit diagrams etc).  So I have started the reverse engineering 
> on the panel.
>
> Does anybody know anything about this computer?  online or offline it would 
> be much appreciated.
>
> Iain

off topic - capatob - saratov2 computer Russsian pdp8? HELP

[Dr Iain Maoileoin via cctalk]

Off topic, but looking for help and/or wisdom.

If you visit https://www.scotnet.co.uk/iain/saratov 
/  you 
will see some photos and wire-lists of work that I have started on the front 
panel of a Capatob 2.

I plan to get the switches and lights running on a blinkenbone board with a 
PDP8 emulation behind it.  (I already have an PDP11/70 front-panel running on 
the same infrastructure)

I have been struggling for over a year to get much info about this saratov 
computer (circuit diagrams etc).  So I have started the reverse engineering on 
the panel.

Does anybody know anything about this computer?  online or offline it would be 
much appreciated.

Iain