Re: Microcode, which is a no-go for modern designs

[Johnny Eriksson via cctalk]

> Few people (but most are right here) can recite PI to enough digits to 
> reach the level of inaccuracy.   And those who believe that PI is exactly 
> 22/7 are unaffected by FDIV.   (YES, some schools do still teach that!)

Why remember the digits, when a small program can provide them?

  +0un qn"E20Un' 0Uh 0uv HK
  Qn
  Qq/10Ut Qh+Qt+48Uw Qw-58"E48Uw %v' Qv"N:Qv,1^T' QwUv Qq-(Qt*10)Uh>
  :Qv,1^T
  !Can you figure out what this macro does before running it?  It was
  written by Stan Rabinowitz with modifications by Mark Bramhall and
  appeared as the Macro of the Month in the Nov. 1977 issue of the TECO
  SIG newsletter, the "Moby Munger".  For information on the TECO Special
  Interest Group, write to Stan at P.O. Box 76, Maynard, Mass. 01754!

--Johnny

Re: Miscellaneous Equipment for free (Mostly DEC) in Lexington KY

[Paul Anderson via cctalk]

Any Uni-bus or PDP8 items? I have plenty of boxes or I would jump on it,
but if some one picks them up I have most of the boards.

Thanks, Paul

On Sun, Jan 6, 2019 at 2:06 PM keith--- via cctech 
wrote:

> Miscellaneous Equipment for free (Mostly DEC) in Lexington KY.  Local
> Pick highly preferred.
>
> I need to empty my storage unit.  I have various pieces available for
> free, local pickup.
>
> One thing to note,  it has not been stored properly.  It has been stored
> in a rental storage unit with no heat or cooling.  I do not know if any
> of the units are still functional and there is no power at the storage
> unit to verify the equipment.
>
> 1) BA23 Chassis.   Was a PDP11/23 at some point but there are no cards
> or drives.  It is in the tower configuration but the front cover is
> missing.
>
> 2) DecStation 3100.  Appears complete and in decent condition.
>
> 3) VT220 terminal.  Very yellowed
>
> 4) A few LK201 keyboards.  Not pretty
>
> 5) VRM17-HA Monitor.  17" monochrome monitor for a Vaxstation.  It did
> work at one time but see above.  Yellowed.
>
> 6) IBM CRT VGA Monochrome monitor
>
> 7) Macintosh SE.  With Ethernet! Very Yellowed.
>
> 8) BA213 Chassis.  Some corrosion and possible water damage.  Back-plane
> looks very good.  Insulation is deteriorating.  This was a Microvax 3500
> at one time until the mice got in.
>
> Picture are available here:
>
> https://www.flickr.com/photos/stupido/albums/72157702145168162
>
> I may add more equipment to the list as I sort things out.  I want to
> empty the storage unit by the end of this month.  Anything that I can't
> or don't want to keep then will go to recycle.
>
> thanks
>
> Max
>

Decus #8-250 Fast Fourier Transform

[David Gesswein via cctalk]

Anybody on the list get these tapes?

https://www.ebay.com/itm/Decus-8-250-Fast-Fourier-Transform-FFT-Software-on-Paper-Tape-for-PDP-8-/192646534861?hash=item2cdaa0d6cd%3Ag%3A4ukAAOSwjexbjeWx=true=pZk7jy9IX%252F2eOztzfa26ClklLrI%253D_cvip=true=true=nc&_trksid=p2047675.l2557

I missed seeing that auction.

RE: off topic - capatob - saratov2 computer Russsian pdp8

[Dave Wade via cctalk]

> -Original Message-
> From: cctalk  On Behalf Of William Donzelli
> via cctalk
> Sent: 06 January 2019 23:21
> To: Bob Smith ; General Discussion: On-Topic and
> Off-Topic Posts 
> Subject: Re: off topic - capatob - saratov2 computer Russsian pdp8
> 
> > With the advent of wide spread introduction of 16 bit machines the
> > definition of a byte as an 8 bit unit was accepted because ASCII
> > supported character sets for multiple languages, before the 8bit
> > standard there were 6 bit, 7 bit variations of he character sets.
> > Gee, what were teletypes, like the model 15, 19, 28, oh yeah 5 level
> > or 5 bit..with no parity.
> 
> Byte was more or less "set in stone" in the mid 1960s, with the success of the
> IBM System/360. During the internal war at IBM to determine whether the
> S/360 was going to be a 6 bit based machine or an 8 bit based machine, a
> study showed that a huge majority of the stored digital data in the world was
> better suited to 8 bits (mainly because of BCD in the financial industry). It 
> had
> nothing to do with terminal communications, as there just was not much of
> that back then.
> When the S/360 turned into the success it was, maybe 1966 or so, it turned
> into an eight bit byte world.
> 
> People on this list keep forgetting just how gigantic IBM was back then, and
> how much influence it had, good or bad.
> 
> --
> Will

I am also pretty sure that prior to S/360 the term "character" was generally 
used for non 8-bit character machines. I am not familiar with the IBM 70xx 
series machines but certainly on the 1401 and 1620 the term byte was never 
used. Also the Honeywell H3200 which was an IBM1401 "clone" (sort of). The only 
machine I know where a "byte" is not eight bits is the Honeywell L6000 and its 
siblings These machines had 36 bit works which were originally divided into 6 
six bit characters. When it became clear that the world was moving to 8-bit 
characters they added new instructions that allowed a word to be treated as 4 
by 9-bit bytes.

I seem to recall that some IBM machines also had facilities to read all 9 bits 
from a 9-track tape as data so 9-bit bytes but I can't find references.

I also feel the use of the term Octet was more marketing to distance ones 
machines from IBM.

Dave

Re: off topic - capatob - saratov2 computer Russsian pdp8

[Guy Sotomayor Jr via cctalk]

> On Jan 6, 2019, at 6:10 PM, Jon Elson via cctalk  
> wrote:
> 
> On 01/06/2019 01:29 PM, Bob Smith via cctalk wrote:
>> Sorry, thanks for playing but
>> Actually half of a WORD is a BYTE, whatever the numerical length is.
>> Ready for this,half of a BYTE is a NIBBLE.
> Well, no.  On 32-bit machines such as IBM 360, VAX, etc. half a 32-bit word 
> is a halfword,
> the fullword is equal to FOUR bytes.  On a 360/65 and above, the memory word 
> was 64 bits, or a double-word, so half that was a fullword.  Just makes it 
> more confusing.

No it doesn’t.  The 360/65 was still a 32-bit processor (as defined by the 
ISA).  It makes no difference what the width to memory was.  Wider memory is 
only to improve the bandwidth to memory.  That’s like saying the current Intel 
ixxx CPUs (which are 64-bit ISA) are “confusing” because the width to memory is 
256-bits.

TTFN - Guy

Re: PDP-11/45 RSTS/E boot problem

[Fritz Mueller via cctalk]

Hi Paul,

> On Jan 6, 2019, at 5:58 PM, Paul Koning  wrote:
> 
> Hm.  Can you read data back from the RK05 pack?  I'd have to refresh my 
> memory on how but it's clearly possible to force a crash dump.  That would 
> allow us to dig into exactly what went wrong, provided you can read the dump 
> file (or the whole disk).

Yes, I can read back, either by sector or the whole pack.  Do let me know if 
you find a way to trigger a crash dump, and I’ll give it a go!

thanks,
  --FritzM.

Re: off topic - capatob - saratov2 computer Russsian pdp8

[Jon Elson via cctalk]

On 01/06/2019 01:29 PM, Bob Smith via cctalk wrote:

Sorry, thanks for playing but
Actually half of a WORD is a BYTE, whatever the numerical length is.
Ready for this,half of a BYTE is a NIBBLE.
Well, no.  On 32-bit machines such as IBM 360, VAX, etc. 
half a 32-bit word is a halfword,
the fullword is equal to FOUR bytes.  On a 360/65 and above, 
the memory word was 64 bits, or a double-word, so half that 
was a fullword.  Just makes it more confusing.


Jon

Re: PDP-11/45 RSTS/E boot problem

[Paul Koning via cctalk]

> On Jan 6, 2019, at 8:01 PM, Fritz Mueller via cctalk  
> wrote:
> 
> 
>> On Jan 5, 2019, at 12:58 PM, Fritz Mueller  wrote:
>> 
>> I did get some MACRO CRC-16 sub-routines coded up last night while waiting 
>> for various transfers, so I think I’ll go ahead and finish up the standalone 
>> CRC dumper utility today.
>> 
>> Lastly, a 5V-tolerant USB FIFO breakout board is supposed to show up in the 
>> mails today.  If that works out as simply as I hope to interface with a 
>> DR11-C, I should have a much better way to blast bits on and off the machine 
>> soon.
> 
> Okay, finished up the standalone CRC utility, and verified (to very long 
> odds) byte identical contents between reading the physical pack on the 
> machine and reading the downloaded pack under SIMH.  And that image doesn’t 
> boot on real HW, but works under SIMH.

Hm.  Can you read data back from the RK05 pack?  I'd have to refresh my memory 
on how but it's clearly possible to force a crash dump.  That would allow us to 
dig into exactly what went wrong, provided you can read the dump file (or the 
whole disk).

paul

Re: PDP-11/45 RSTS/E boot problem

[Fritz Mueller via cctalk]

Oh, one last thing: if anybody else out there has a real working '11/45 + RK05 
and wants to try this RSTS image, let me know, and I’ll send you a copy (all 
2.5MB of it, hah).  It’d be interesting to see if this a really just limited to 
my machine?

--FritzM.

Re: PDP-11/45 RSTS/E boot problem

[Fritz Mueller via cctalk]

> On Jan 5, 2019, at 12:58 PM, Fritz Mueller  wrote:
> 
> I did get some MACRO CRC-16 sub-routines coded up last night while waiting 
> for various transfers, so I think I’ll go ahead and finish up the standalone 
> CRC dumper utility today.
> 
> Lastly, a 5V-tolerant USB FIFO breakout board is supposed to show up in the 
> mails today.  If that works out as simply as I hope to interface with a 
> DR11-C, I should have a much better way to blast bits on and off the machine 
> soon.

Okay, finished up the standalone CRC utility, and verified (to very long odds) 
byte identical contents between reading the physical pack on the machine and 
reading the downloaded pack under SIMH.  And that image doesn’t boot on real 
HW, but works under SIMH.

I’ll post the CRC utility code up on my '11/45 project blog 
(http://fritzm.github.io/category/pdp-11.html) when I do a write-up later 
tonight, in case anybody else is interested in it.

So, I’m left with something probably odd with my HW tripping up RSTS but not 
being caught by MAINDECs :-(  I think I’ll switch gears for a bit and work on 
the USB FIFO to DR11-C hack, since that will help make further experimentation 
much faster in general.

cheers,
  --FritzM.

Re: ISO - 386 or 486 system or cplt mobo

[Randy Dawson via cctalk]

We use a website called 'nextdoor' which is a neighborhood community exchange.  
I posted a message asking for the same, old PC's.

In a coupe of days I picked up 5 of them for free.

Two were VERY unique, belonging to a LA area movie editor.  They came with high 
end Matrox frame grabber/video cards for component video in/out and production.

Randy


From: cctalk  on behalf of drlegendre via cctalk 

Sent: Sunday, January 6, 2019 2:53 PM
To: Devin; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: ISO - 386 or 486 system or cplt mobo

Devin,

Do you have boards or complete machines?  Very interested to see some pics.

Thanks for your help,
Bill

On Sun, Jan 6, 2019, 12:53 AM devin davison via cctalk <
cctalk@classiccmp.org wrote:

> I have a stockpile of them. Will get you pictures tomorrow.
>
> On Sat, Jan 5, 2019, 11:59 PM Will Cooke via cctalk  >
> wrote:
>
> >
> > > On January 5, 2019 at 8:42 PM drlegendre via cctalk <
> > cctalk@classiccmp.org> wrote:
> > >
> > >
> > > I'm interested in finding a 386 or slow 486 machine or moboj ust for
> > > playing DOS games. Does anyone have such a thing sitting around,
> looking
> > > for a home?
> > >
> > > Thanks in advance.
> >
> > I have a couple of 386sx motherboards with I think 1MB ram.  I thought I
> > had a full 386 board with 8MB ram but I can't seem to find it.  Would one
> > of those work for you?
> >
> > Will
> >
> >
> > "He may look dumb but that's just a disguise."  -- Charlie Daniels
> >
> >
> > "The names of global variables should start with// "  --
> > https://isocpp.org
> >
>

Re: off topic - capatob - saratov2 computer Russsian pdp8

[William Donzelli via cctalk]

> With the advent of wide spread introduction of 16 bit machines the
> definition of a byte as an 8 bit unit was accepted because ASCII
> supported character sets for multiple languages, before the 8bit
> standard there were 6 bit, 7 bit variations of he character sets.
> Gee, what were teletypes, like the model 15, 19, 28, oh yeah 5 level
> or 5 bit..with no parity.

Byte was more or less "set in stone" in the mid 1960s, with the
success of the IBM System/360. During the internal war at IBM to
determine whether the S/360 was going to be a 6 bit based machine or
an 8 bit based machine, a study showed that a huge majority of the
stored digital data in the world was better suited to 8 bits (mainly
because of BCD in the financial industry). It had nothing to do with
terminal communications, as there just was not much of that back then.
When the S/360 turned into the success it was, maybe 1966 or so, it
turned into an eight bit byte world.

People on this list keep forgetting just how gigantic IBM was back
then, and how much influence it had, good or bad.

--
Will

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: ISO - 386 or 486 system or cplt mobo

[drlegendre via cctalk]

Devin,

Do you have boards or complete machines?  Very interested to see some pics.

Thanks for your help,
Bill

On Sun, Jan 6, 2019, 12:53 AM devin davison via cctalk <
cctalk@classiccmp.org wrote:

> I have a stockpile of them. Will get you pictures tomorrow.
>
> On Sat, Jan 5, 2019, 11:59 PM Will Cooke via cctalk  >
> wrote:
>
> >
> > > On January 5, 2019 at 8:42 PM drlegendre via cctalk <
> > cctalk@classiccmp.org> wrote:
> > >
> > >
> > > I'm interested in finding a 386 or slow 486 machine or moboj ust for
> > > playing DOS games. Does anyone have such a thing sitting around,
> looking
> > > for a home?
> > >
> > > Thanks in advance.
> >
> > I have a couple of 386sx motherboards with I think 1MB ram.  I thought I
> > had a full 386 board with 8MB ram but I can't seem to find it.  Would one
> > of those work for you?
> >
> > Will
> >
> >
> > "He may look dumb but that's just a disguise."  -- Charlie Daniels
> >
> >
> > "The names of global variables should start with// "  --
> > https://isocpp.org
> >
>

Re: ISO - 386 or 486 system or cplt mobo

[drlegendre via cctalk]

Very cool, thanks! I'll keep an eye out for the photos.

On Sun, Jan 6, 2019, 12:53 AM devin davison via cctalk <
cctalk@classiccmp.org wrote:

> I have a stockpile of them. Will get you pictures tomorrow.
>
> On Sat, Jan 5, 2019, 11:59 PM Will Cooke via cctalk  >
> wrote:
>
> >
> > > On January 5, 2019 at 8:42 PM drlegendre via cctalk <
> > cctalk@classiccmp.org> wrote:
> > >
> > >
> > > I'm interested in finding a 386 or slow 486 machine or moboj ust for
> > > playing DOS games. Does anyone have such a thing sitting around,
> looking
> > > for a home?
> > >
> > > Thanks in advance.
> >
> > I have a couple of 386sx motherboards with I think 1MB ram.  I thought I
> > had a full 386 board with 8MB ram but I can't seem to find it.  Would one
> > of those work for you?
> >
> > Will
> >
> >
> > "He may look dumb but that's just a disguise."  -- Charlie Daniels
> >
> >
> > "The names of global variables should start with// "  --
> > https://isocpp.org
> >
>

IDOL/VS Manual

[Jason T via cctalk]

I am preparing to scan this manual on the IDOL/VS database system, which
was initially a product of "Systems Specialties" but was later purchased by
MAI for their Basic Four systems.

I can't find any documentation on this product on Bitsavers or anywhere
else.  If anyone is aware of this manual online, please let me know.

And if anyone wants the original once it's scanned, I'll be happy to send
it for the cost of postage from 60070.

J

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: Microcode, which is a no-go for modern designs

[Fred Cisin via cctalk]

Pentiums and it was a real hassle to have to field all those beefs from
customers whose EXPENSIVE processors couldn't divide accurately.


no
It was a real hassle to have to field all those beefs from customers who 
had a PERCEPTION that their expensive processors Wouldn't divide 
accurately.


There was a serious problem with public perception, and further fueled by 
talk show comedians, that all bank statements would be wrong, that 
missiles would hit the wrong cities, that airplanes couldn't find the 
right airport, . . .   AND that all arithmetic in all computers is done 
with floating point.


Few people (but most are right here) can recite PI to enough digits to 
reach the level of inaccuracy.   And those who believe that PI is exactly 
22/7 are unaffected by FDIV.   (YES, some schools do still teach that!)



Intel needed to do much better on their PR.  There was a public perception 
that Intel said that they would only replace them for people who could 
PROVE that their work was directly affected.


Instead, Intel needed to make it CLEAR that "ALL will be replaced, at no 
charge.  But, we need a little time to make a few more, SO, we will start 
by replacing those for which the work is directly affected, and replace 
ALL of them as quickly as more are made."


MOST owners would not hit the error during the life of the machine. Most 
power lUsers would have already upgraded to a newer machine (those who 
were screaming the loudest, "upgrade" to a newer machine several times 
a year, even though they don't replace their car EVERY year).


--
Grumpy Ol' Fred ci...@xenosoft.com
3.14159265358979

Re: off topic - capatob - saratov2 computer Russsian pdp8

[Paul Koning via cctalk]

> On Jan 6, 2019, at 2:34 PM, Bob Smith via cctalk  
> wrote:
> 
> With the advent of wide spread introduction of 16 bit machines the
> definition of a byte as an 8 bit unit was accepted because ASCII
> supported character sets for multiple languages, before the 8bit
> standard there were 6 bit, 7 bit variations of he character sets.
> Gee, what were teletypes, like the model 15, 19, 28, oh yeah 5 level
> or 5 bit..with no parity.

I think some of this discussion suffers from not going far enough back in 
history.

"Byte" was a term used a great deal in the IBM/360 series, where it meant 8 
bits.  Similarly "halfword" (16 bits).  But as was pointed out, mainframes in 
that era had lots of different word sizes: 27, 32, 36, 48, 60...  Some of them 
(perhaps not all) also used the term "byte" to mean something different.  In 
the PDP-10, it has a well defined meaning: any part of a word, as operated on 
by the "byte" instructions -- which the VAX called "bit field instructions".  6 
and 9 bit sizes were common for characters, and "byte" without further detail 
could have meant any of those.  In the CDC 6000 series, characters were 6 or 12 
bits, and either of those could be "byte".

"Nybble" is as far as I can tell a geek joke term, rather than a widely used 
standard term.  "Halfword" is 16 bits on IBM 360 and VAX, 18 on PDP-10, and 
unused on CDC 6000.  Then there are other subdivisions with uncommon terms, 
like "parcel" (15 bits, CDC 6000 series, the unit used by the instruction issue 
path).

ASCII was originally a 7 bit code.  There were other 7 bit codes at that time, 
like the many variations of Flexowriter codes; 6 bit codes (found in 
typesetting systems and related stuff such as news wire service data feeds), 
and 5 bit codes (Telex codes, again in many variations).

paul

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

[Bob Smith via cctalk]

With the advent of wide spread introduction of 16 bit machines the
definition of a byte as an 8 bit unit was accepted because ASCII
supported character sets for multiple languages, before the 8bit
standard there were 6 bit, 7 bit variations of he character sets.
Gee, what were teletypes, like the model 15, 19, 28, oh yeah 5 level
or 5 bit..with no parity.

On Sun, Jan 6, 2019 at 2:29 PM Bob Smith  wrote:
>
> Sorry, thanks for playing but
> Actually half of a WORD is a BYTE, whatever the numerical length is.
> Ready for this,half of a BYTE is a NIBBLE. In fact, in common usage,
> word has become synonymous with 16 bits, much like byte has with 8
> bits.
> What's the difference between a word and byte? - Stack Overflow
> https://stackoverflow.com/questions/.../whats-the-difference-between-a-word-and-byte
> Feedback
> About this result
>
> On Sun, Jan 6, 2019 at 1:48 PM Jeffrey S. Worley via cctalk
>  wrote:
> >
> > On Sun, 2019-01-06 at 12:00 -0600, cctalk-requ...@classiccmp.org wrote:
> > > Re: off topic - capatob - saratov2 computer Russsian pdp8
> >
> > Nothing has changed as regards the number of bits in a byte, a nybble
> > is 4 bits, 8 to the byte, and x to the word - this last varies widely
> > depending on architecture.
> >
> > Still, in Spirit, on an octal processor a whole number is a six bit
> > 'byte', so the term is appropriate, especially to avoid confusion with
> > the word size of two six bit 'bytes'.
> >
> > Fun.
> >
> > Jeff
> >

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: OT? Upper limits of FSB

[dwight via cctalk]

Probably the factor that most think limits thing is the turn-around time. If 
they were limited to one byte request and wait for that data to return, the 
limits of wires would be a wall. Today's serial RAMs send a burts of data 
rather than a word or byte at a time. These blocks of data can use multiple 
serial lanes at one time where the data bits aren't even exactly arriving at 
the same time. There are FIFOs and parallelizers that bring things back 
together. The latency of the first fetch is slower than it used to be for 
traditional fetches but after that things are quite quick. Surprisingly, this 
is actually good for older languages like Forth that are fugal with RAM. Entire 
applications ( less data in some cases ) can be in the CPU's cache for 
immediate use.
Dwight

From: cctalk  on behalf of Curious Marc via 
cctalk 
Sent: Saturday, January 5, 2019 9:40 PM
To: Jeffrey S. Worley; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: OT? Upper limits of FSB

Interconnects at 28Gb/s/lane have been out for a while now, supported by quite 
a few chips. 56Gb/s PAM4 is around the corner, and we run 100Gb/s in the lab 
right now. Just sayin’ ;-). That said, we throw in about every equalization 
trick we know of, PCB materials are getting quite exotic and connectors are 
pretty interesting. We have to hand hold our customers to design their 
interconnect traces and connector breakouts. And you can’t go too far, with 
increasing reliance on micro-twinax or on-board optics for longer distances and 
backplanes.
Marc

> On Jan 4, 2019, at 11:02 PM, Jeffrey S. Worley via cctalk 
>  wrote:
>
> Apropos of nothing, I've been confuse for some time regarding maximum
> clock rates for local bus.
>
> My admittedly old information, which comes from the 3rd ed. of "High
> Performance Computer Architecture", a course I audited, indicates a
> maximum speed on the order of 1ghz for very very short trace lengths.
>
> Late model computers boast multi-hundred to multi gigahertz fsb's.  Am
> I wrong in thinking this is an aggregate of several serial lines
> running at 1 to 200mhz?  No straight answer has presented on searches
> online.
>
> So here's the question.  Is maximum fsb on standard, non-optical bus
> still limited to a maximum of a couple of hundred megahertz, or did
> something happen in the last decade or two that changed things
> dramatically?  I understand, at least think I do, that these
> ridiculously high frequency claims would not survive capacitance issues
> and RFI issues. When my brother claimed a 3.2ghz bus speed for his
> machine I just told him that was wrong, impossible for practical
> purposes, that it had to be an aggregate figure, a 'Pentium rating'
> sort of number rather than the actual clock speed.  I envision
> switching bus tech akin to present networking, paralleled to sidestep
> the limit while keeping pin and trace counts low.?  Something like
> the PCIe 'lane' scheme in present use?  This is surmise based on my own
> experience.
>
> When I was current, the way out of this limitation was fiber-optics for
> the bus.  This was used in supercomputing and allowed interconnects of
> longer length at ridiculous speeds.
>
> Thanks for allowing me to entertain this question.  Though it is not
> specifically a classic computer question, it does relate to development
> and history.
>
>
>
> Best,
>
> Technoid Mutant (Jeff Worley)
>
>
>
>
>

Re: off topic - capatob - saratov2 computer Russsian pdp8

[Bob Smith via cctalk]

Sorry, thanks for playing but
Actually half of a WORD is a BYTE, whatever the numerical length is.
Ready for this,half of a BYTE is a NIBBLE. In fact, in common usage,
word has become synonymous with 16 bits, much like byte has with 8
bits.
What's the difference between a word and byte? - Stack Overflow
https://stackoverflow.com/questions/.../whats-the-difference-between-a-word-and-byte
Feedback
About this result

On Sun, Jan 6, 2019 at 1:48 PM Jeffrey S. Worley via cctalk
 wrote:
>
> On Sun, 2019-01-06 at 12:00 -0600, cctalk-requ...@classiccmp.org wrote:
> > Re: off topic - capatob - saratov2 computer Russsian pdp8
>
> Nothing has changed as regards the number of bits in a byte, a nybble
> is 4 bits, 8 to the byte, and x to the word - this last varies widely
> depending on architecture.
>
> Still, in Spirit, on an octal processor a whole number is a six bit
> 'byte', so the term is appropriate, especially to avoid confusion with
> the word size of two six bit 'bytes'.
>
> Fun.
>
> Jeff
>

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: Microcode, which is a no-go for modern designs

[Jeffrey S. Worley via cctalk]

On Sun, 2019-01-06 at 11:08 -0800, Josh Dersch wrote:
> That's a good trick, given that the K5 came out in 1996 and the K6 in
> 1997, the FDIV issue blew up in late 1994.

Memory is like that.  The FDIV bug didn't go away because it was
announced, the chips stayed on desktops and our diagnostic software
frequently contained the FDIV patch to deal with such, for the rest of
the decade.

I went from a 486dlc-40 to a 4x86 dx2 80 to a k5 133 to a k6 to a k6 to
a k6 to a celeron.  Amd kept releasing faster k6's. My last, in the
late 90's, was IIRC a 333mhz model.

I was a tech in Miami at the time FDIV happened, working for Victors
DataSouth and it's Novell networks.  My servers ran 486's but we sold
Pentiums and it was a real hassle to have to field all those beefs from
customers whose EXPENSIVE processors couldn't divide accurately.

In 95' I went to work in Asheville, NC for Uptime Computer Services and
saw a bunch of machines cross my desk which needed the software patch.

In 2000 I was working with Bits and Bytes computer services.


Best,

Jeff

Re: Microcode, which is a no-go for modern designs

[Grant Taylor via cctalk]

On 1/6/19 11:59 AM, Jeffrey S. Worley via cctalk wrote:
I was a tech in the 90's when the original Pentium FDIV bug was storming. 
The issue was confined to the integrated floating point portion of the 
processor and was therefore rarely an issue as the vast majority of 
software did not use the mathco portion of the chip.  Only a handful of 
applications and relative handful of users were affected.  This became 
Intel's position on the matter and they hoped the issue would just die 
down to those handful whom they would provide new chips.


The issue did not die down and the bad press forced the decision to 
replace ALL pentiums affected.  Only a relative few were actually replaced 
in the home and small business arena.  A software patch was a common 
solution to the problem.  It masssaged input to the FDIV instruction to 
produce a corrected result and worked pretty well as I recall.


I suspect that Intel is longing for the Pentium FDIV bug days after the 
speculative execution issues that have surfaced (and gained traction) in 
2018.




--
Grant. . . .
unix || die

Re: Microcode, which is a no-go for modern designs

[Josh Dersch via cctalk]

On Sun, Jan 6, 2019 at 10:59 AM Jeffrey S. Worley via cctalk <
cctalk@classiccmp.org> wrote:

> On Sat, 2019-01-05 at 12:00 -0600, cctalk-requ...@classiccmp.org wrote:
> > Re: Microcode, which is a no-go for modern designs
>
> I was a tech in the 90's when the original Pentium FDIV bug was
> storming.  The issue was confined to the integrated floating point
> portion of the processor and was therefore rarely an issue as the vast
> majority of software did not use the mathco portion of the chip.  Only
> a handful of applications and relative handful of users were affected.
> This became Intel's position on the matter and they hoped the issue
> would just die down to those handful whom they would provide new chips.
>
> The issue did not die down and the bad press forced the decision to
> replace ALL pentiums affected.  Only a relative few were actually
> replaced in the home and small business arena.  A software patch was a
> common solution to the problem.  It masssaged input to the FDIV
> instruction to produce a corrected result and worked pretty well as I
> recall.
>
> At the time of the storm, the Pentium was still pretty new and very
> expensive.  Most folks were getting along with AMD k5 and k6
> processors.  I WAS.  I went from k6 to Celeron.
>

That's a good trick, given that the K5 came out in 1996 and the K6 in 1997,
the FDIV issue blew up in late 1994.

- Josh



>
> Best
>
> Jeff
>
>

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: Microcode, which is a no-go for modern designs

[Jeffrey S. Worley via cctalk]

What defines a 'modern processor'.  The term is pretty slippery.

The Crusoe used microcode to emulate x86 and could therefore emulate
any processor architecture Transmeta wanted.

Crusoe was a pioneer in the low power market, the processor dynamically
clocked itself in very small steps depending on need.  This is a
familiar feature now but was pretty revolutionary for the time. 
Interestingly, Linux Torvalds was in on the design and was on the board
of Transmeta.  A fair number were sold to Sony for their VIAO series of
notebooks.

Does Crusoe qualify as a 'modern' processor?  In my book yes, but I
have a very old book.. :0
best,

Jeff

Re: Microcode, which is a no-go for modern designs

[Jeffrey S. Worley via cctalk]

On Sat, 2019-01-05 at 12:00 -0600, cctalk-requ...@classiccmp.org wrote:
> Re: Microcode, which is a no-go for modern designs

I was a tech in the 90's when the original Pentium FDIV bug was
storming.  The issue was confined to the integrated floating point
portion of the processor and was therefore rarely an issue as the vast
majority of software did not use the mathco portion of the chip.  Only
a handful of applications and relative handful of users were affected. 
This became Intel's position on the matter and they hoped the issue
would just die down to those handful whom they would provide new chips.

The issue did not die down and the bad press forced the decision to
replace ALL pentiums affected.  Only a relative few were actually
replaced in the home and small business arena.  A software patch was a
common solution to the problem.  It masssaged input to the FDIV
instruction to produce a corrected result and worked pretty well as I
recall.

At the time of the storm, the Pentium was still pretty new and very
expensive.  Most folks were getting along with AMD k5 and k6
processors.  I WAS.  I went from k6 to Celeron.

Best

Jeff 

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: Microcode dated?

[Jeffrey S. Worley via cctalk]

On Sun, 2019-01-06 at 12:00 -0600, cctalk-requ...@classiccmp.org wrote:
> Send cctalk mailing list submissions to
>   cctalk@classiccmp.org
> 
> To subscribe or unsubscribe via the World Wide Web, visit
>   http://www.classiccmp.org/mailman/listinfo/cctalk
> or, via email, send a message with subject or body 'help' to
>   cctalk-requ...@classiccmp.org
> 
> You can reach the person managing the list at
>   cctalk-ow...@classiccmp.org
> 
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of cctalk digest..."
> 
> 
> Today's Topics:
> 
>1. Re: ELTRAN THE COMPILER ANY DOCS? (NOT THE SEMICONDUCTOR
>   STUFF!))) (Chuck Guzis)
>2. Re: ELTRAN THE COMPILER ANY DOCS? (NOT THE SEMICONDUCTOR
>   STUFF!))) (Chuck Guzis)
>3. Re: ELTRAN THE COMPILER ANY DOCS? (NOT THE SEMICONDUCTOR
>   STUFF!))) (ED SHARPE)
>4. off topic - capatob - saratov2 computer Russsian pdp8? HELP
>   (Dr Iain Maoileoin)
>5. Re: ELTRAN THE COMPILER ANY DOCS? (NOT THE SEMICONDUCTOR
>   STUFF!))) (ED SHARPE)
>6. Re: PDP-11/45 RSTS/E boot problem (Fritz Mueller)
>7. uc04 + scsi2sd ? (Jacob Ritorto)
>8. Re: uc04 + scsi2sd ? (Richard Cini)
>9. KD11-E/EA microcode flow diagrams (Noel Chiappa)
>   10. Re: KD11-E/EA microcode flow diagrams (Fritz Mueller)
>   11. Re: PDP-11/45 RSTS/E boot problem (Jerry Weiss)
>   12. Re: uc04 + scsi2sd ? (Jerry Weiss)
>   13. Re: PDP-11/45 RSTS/E boot problem (Fritz Mueller)
>   14. ISO - 386 or 486 system or cplt mobo (drlegendre)
>   15. Re: ISO - 386 or 486 system or cplt mobo (wrco...@wrcooke.net)
>   16. SMECC on the hunt  for Monarch hp 150 poster  do U have  one?
>   or a hi res clean scan? (ED SHARPE)
>   17. Re: uc04 + scsi2sd ? (Al Kossow)
>   18. Re: uc04 + scsi2sd ? (Josh Dersch)
>   19. Re: PDP-11/45 RSTS/E boot problem (Tony Duell)
>   20. Re: PDP-11/45 RSTS/E boot problem (Jerry Weiss)
>   21. Re: OT? Upper limits of FSB (Curious Marc)
>   22. Re: PDP-11/45 RSTS/E boot problem (Fritz Mueller)
>   23. Re: PDP-11/45 RSTS/E boot problem (Tony Duell)
>   24. Re: PDP-11/45 RSTS/E boot problem (Fritz Mueller)
>   25. Re: ISO - 386 or 486 system or cplt mobo (devin davison)
>   26. Re: off topic - capatob - saratov2 computer Russsian pdp8?
>   HELP (Bob Smith)
>   27. Re: off topic - capatob - saratov2 computer Russsian pdp8?
>   HELP (Grant Taylor)
> 
> 
> ---
> ---
> 
> Message: 1
> Date: Sat, 5 Jan 2019 10:10:04 -0800
> From: Chuck Guzis 
> To: Fred Cisin via cctalk 
> Subject: Re: ELTRAN THE COMPILER ANY DOCS? (NOT THE SEMICONDUCTOR
>   STUFF!)))
> Message-ID: <1651425f-f406-205d-5284-1e6fd1d7c...@sydex.com>
> Content-Type: text/plain; charset=utf-8
> 
> Okay, I think I found the reference to it.
> 
> It turns out that it was a high-school student's project entered in
> the
> "Fourth Annual Computer Programming Contest for Grades 7 to 12'.  To
> quote:
> 
> "The 1966 winner was William J. Elliott, a 12th grade student at West
> High School in Minneapolis.  His project, ELTRAN, is an algorithmic
> language compiler system for the UNIVAC 422 computer.  Until the
> development of ELTRAN, no compiler existed for the computer."
> 
> See PDF page 10 here:
> 
> http://www.bitsavers.org/pdf/computersAndAutomation/196701.pdf
> 
> --Chuck
> 
> P.S.  One of these days, I'm going to host a course on "how to use
> Google".
> 
> 
> --
> 
> Message: 2
> Date: Sat, 5 Jan 2019 10:17:52 -0800
> From: Chuck Guzis 
> To: Chuck Guzis via cctalk 
> Subject: Re: ELTRAN THE COMPILER ANY DOCS? (NOT THE SEMICONDUCTOR
>   STUFF!)))
> Message-ID: <6e237124-1ac7-700d-b9be-beda8f3a0...@sydex.com>
> Content-Type: text/plain; charset=utf-8
> 
> Since it was a 53-year old high-school project, I doubt that you're
> going to find much on it.   However, see the post by Steve Schweda
> here:
> 
> https://community.hpe.com/t5/Operating-System-OpenVMS/Left-shift-by-more-than-32-bits-gt-undefined-in-DEC-C/td-p/5054212
> 
> He may actually have some familiarity with ELTRAN and know where some
> documentation exists.
> 
> --Chuck
> 
> 
> 
> 
> On 1/5/19 10:10 AM, Chuck Guzis via cctalk wrote:
> > Okay, I think I found the reference to it.
> > 
> > It turns out that it was a high-school student's project entered in
> > the
> > "Fourth Annual Computer Programming Contest for Grades 7 to
> > 12'.  To quote:
> 
> --
> 
> Message: 3
> Date: Sat, 5 Jan 2019 18:21:53 + (UTC)
> From: ED SHARPE 
> To: cctalk@classiccmp.org
> Subject: Re: ELTRAN THE COMPILER ANY DOCS? (NOT THE SEMICONDUCTOR
>   STUFF!)))
> Message-ID: <1152753582.13550260.1546712513...@mail.yahoo.com>
> Content-Type: text/plain; charset=UTF-8
> 
> (COME ON SOCRATES ...? DO YOUR? THING!)
> 
> In a message dated 1/5/2019 1:49:38 AM US Mountain Standard Time, 
> cctalk@classiccmp.org writes:
> 
> no is compiler a small one only 2 do loops 

Re: ELTRAN THE COMPILER ANY DOCS? (NOT THE SEMICONDUCTOR STUFF!)))

[John Foust via cctalk]

At 12:10 PM 1/5/2019, Chuck Guzis via cctalk wrote:
>Okay, I think I found the reference to it.
>
>It turns out that it was a high-school student's project entered in the
>"Fourth Annual Computer Programming Contest for Grades 7 to 12'.  To quote:
>
>"The 1966 winner was William J. Elliott, a 12th grade student at West
>High School in Minneapolis. 


Clearly we should track him down.  How many 70-year-old William J. Elliots 
could there be?

- John

Re: off topic - capatob - saratov2 computer Russsian pdp8

[Jeffrey S. Worley via cctalk]

On Sun, 2019-01-06 at 12:00 -0600, cctalk-requ...@classiccmp.org wrote:
> Re: off topic - capatob - saratov2 computer Russsian pdp8

Nothing has changed as regards the number of bits in a byte, a nybble
is 4 bits, 8 to the byte, and x to the word - this last varies widely
depending on architecture.

Still, in Spirit, on an octal processor a whole number is a six bit
'byte', so the term is appropriate, especially to avoid confusion with
the word size of two six bit 'bytes'.

Fun.

Jeff

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