I was wondering if anyone knew the particulars about the PS/2 SCSI
external connector on the model 80 server I have. It appears to be a
miniature high density 60 pin connector, This is totally different than
the standard SCSI 2 or 3 connections that I've seen. Is there an adapter
available to be able to hook it to a standard SCSI I, II or III
cable/connector? I want to be able to use my CDROM towers with it if
possible.
--------------------------------------------------------------------
Russ Blakeman
RB Custom Services / Rt. 1 Box 62E / Harned, KY USA 40144
Phone: (502) 756-1749 Data/Fax:(502) 756-6991
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ICQ UIN #1714857
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* Parts/Service/Upgrades and more for MOST Computers*
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On Apr 23, 0:57, Tony Duell wrote:
> Indeed. What's worrying is how few people spotted it :-)
>
> When I started in computing all those years ago, I was told 'Don't worry
> about the CPU. It's just a pile of gates and flip-flops like the one's you're
> used to'. Now, admittedly you don't generally see the schematics of a
> microprocesor (although I have understood minis to gate level), but
> there's nothing magic about a CPU.
Agreed. We don't have much on the innards of CPUs at gate level but there's a
1st year course on basic architectures (lots of PDP-11 and -10, IBM, and M68K
stuff), a 2nd year course that teaches about bigger building blocks (pipelines,
ALUs, register banks, cache, etc), and third year stuff on different
architectures (mostly parallel architectures). Everybody has to do the basic
electronic logic course which runs all year in 1st year.
> I hate to say this, but you can't learn this in a couple of practicals.
> Just as you can't learn programming that way. You have to _play_ - build
> circuits, write programs - and keep on at it..
True, but a lot of people just aren't interested. Nevertheless, our first year
course starts with basic gates and has something like 18 or 20 practical
exercises, from investigating glitches in a SPICE model of a NAND gate, to a
traffic light sequencer, a model RAM, a digital die using a PAL, and a few
other things I've forgotten. And everybody has to do it, not just the hardware
buffs.
One of the most popular courses is the 2nd-year follow-up, in which students
are given a problem to solve involving breadboarding a small Z80 system
(CPU/ROM/RAM/LCD/glue + whatever analogue stuff is required). The problem is
different every year, and there's no formal tuition. You can ask the lecturer
or demonstrators any questions you like, and you'll get the answers, but you
have to learn yourself. You don't get taught (in the conventional way).
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Well, folks, it looks like I lied in my recent post about not having
a PDP-11.
Actually, I _do_ have one. I simply forgot that I had, stashed
away, an 11/23 CPU and some boards ("common as houseflies" was the
term Allison used? :> ) Since it was not in a rack, and since
the pieces have never been assembled, and since I have no disks for
it, I pretty much forgot about it, and I've never had it working.
But it appears I have a fairly nice, complete system, board-wise.
Here's what I have:
-----
Chassis: DBA11-N
Cards:
1. M8186 (KDF11-AA) 11/23 CPU with KTF11-AA (MMU), sockets for FP11
2. M8047-CA (MXV11-AC) 16-Kword RAM, 2 async EIA SLU, w/ 2 24-pin ROMs
3. M8047-CA (MXV11-AC) 16-Kword RAM, 2 async EIA SLU, sockets for ROMs
4. M8044-DB (MSV11-DD) 32-Kword 16-bit MOS RAM
5. M8044-DC (MSV11-DD) 32-Kword 16-bit MOS RAM
6. M7269 (RKV11) RK05 controller
7. Data Systems Design 818836-01 REV B -- RX01, RX02, or RX50 controller??
(25-pin ribbon-cable connector)
-----
So, in order to get this whole thing working again, I have a
WHOLE SLEW of questions to ask folks, in no particular order.
Here goes.
1) The M8047-CA boards need to be wire-wrapped to assign their
address vectors -- they're combination MOS RAM and Async EIA,
and I have no docs for them. Can anyone guide me to some info,
or tell me how to jumper one of them to be console serial
port, and the other to be next in line on the bus?
The wire-wrap pins have absolutely no markings on them, not
even any single-letter or number labels, so this one could
require ASCII-art to describe :)
2) Same as above, but for the M8044-DB boards. I could put one
of these in with the M8047's to get a full 64Kword of RAM, yes?
Does anyone know what the DIP-switch settings for these boards
are?
3) I'd love to have the RK05 controller in there, in the hopes
that someday I'll have an RK05 to play with. Just like the
above... How do I jumper it, and where (physically) in the
Bus should I put it?
4) Actually, that raises a good question. All of these boards
are single-height (1/2 the width of the Q-bus backplane).
I know there is some special physical layout the boards should
use when they populate the backplane, but what is it?
My best (probably wrong) guess right now is:
CPU in row 1, slot 1 (is that left or right?),
M8047's in row 2, slots 1 and 2,
M8044 in row 3, slot 1,
M7269 in row 4, slot 1, DSD controller in row 4, slot 2.
Does that make any sense? Should the CPU only live in the
first row, not RAM? I seem to remember something like this
from the darkest depths of my mind, but I don't remember
for sure.
5) OK, simple question, one I've wondered about but never bothered
getting answered because I felt like a complete idiot moron
asking it: Does the QBUS need to be terminated by a special
card in any way, in order to work?
6) What's the pin-out on the M8047 EIA ports? They're 9-pin Berg
connectors, and I need to build a cable for them to connect
either to 9-pin or 25-pin PC-style serial in order to set up
any kind of console terminal.
7) Anyone know what the Data Systems Design board is? It has
"RX" stensiled onto the board near the jumper block, among
other things like "BOOT", so I assume it's some sort of RX01
or RX50 controller or some such.
WHEW, that's _too_ many questions. Anyone who can tackle one of them
gets my respect, and you may award yourself one cookie.
I'd like to piece this system together and get it working to the
point where I can play with it and at least fiddle with the monitor
again, playing with Octal. And I'd dearly love to put it in a
proper DEC desk-side rack with an RK05, but that comes later...
Thanks much,
-Seth
<From: Captain Napalm <spc(a)armigeron.com>
< I think the PDP-11 has only three things in common with the Alpha:
<
< D E C
ROTFL-TB!!!
Sorta like my earlier answer about x86 VS PDP-11...
< If the PDP-11 is anything like the VAX in terms of instruction space, i
<might be possible. The only hitch is unaligned reads/writes to memory (I
Similar to vax. PDP11 is a word machine and instruction words must fall
on even addresses.
< I don't think so. The current trend in CPU design in away from comple
<instruction sets (which is something the VAX is) and more towards simplif
PDP-11 was a very CISC machine.
< Check bask issues of Byte (pre '88 - your local library or university
<library might have them). Full schematics for a slew of computers (mostl
<from Steve Ciarcia) and in the Sep/Oct '85 issues the schematic for a CPU
<Ah, if only I had the time and equipment ...
EGO, I have those issues. simple but not a good design as the sequencer
is really complex and microcoded would have been far far simpler and
easier to debug. Otherwise it tried to copy the two address scheme
PDP11 used but it's not orthogonal.
Allison
Yes it is in octal. If you noticed the keypad has numbers from 0 to 7 so the
whole system works in base 8.
The R key is a hardwired reset.
and the A, B, and C keys are not used by the KEX program.
By the way this kit was also called the Mini Micro Designer (MMD-1) and was
distributed by Circuit Design, inc. for $125 in kit form.
Francois
-------------------------------------------------------------
Visit the Sanctuary at: http://www.pclink.com/fauradon
-----Original Message-----
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, April 16, 1998 6:17 PM
Subject: Re: 8080 Trainer - more info
>>
>> This Trainer was called the Dyna-Micro
>> Here is the Memory allocation:
>
>Thanks for this info (and thanks to Glenn for posting the ROM listing).
>It looks like I'll be able to get it working...
>
>> Hi Lo
>> 000 000 \
>> > Key Prom
>> 000 377 /
>> 001 000 \
>> > Optional ROM
>> 002 377 /
>
>I now have to work out which socket is which. Shouldn't take long - I
>recognise all the chips, have data one them, and it's quite simple. Don't
>spoil it for me by posting the answer just yet ;-)
>
>> 002 000 \
>> > Optional R/W Memory
>> 003 377 /
>
>002 377 ? I think. I assume you're using an octal representation of each
>byte of the address here - something 8080 people often did. I think I
>have the option RAM on my machine. At least, there are no spare sockets
>in that area (4 RAM chips fitted).
>
>> 003 000 \
>> > R/W Memory
>> 003 377 /
>> 004 000 \
>> > Available for user expansion
>> 377 377 /
>>
>> Will post more later
>> Does anyone knows where I can find a 1702 programmed with KEX?
>
>Well, if I get my machine working, I'll probably have to program a 1702
>on the old Intellec. In which case I'd be able to make a few for other
>people if they send me blanks.
>
>But it might just be easier to put it into a 2716 or 2764 and make up a
>kludge board (or if you're building a machine from scratch, just design
>the board to take one).
>
>> Francois
>
>-tony
>
<But, since Alphas must share SOMETHING in common with the PDP-11,
<wouldn't it be possible to write a normal program for the Alpha,
<running under NT or Linux, that would give PDP emulation at P-II-like
Not even close. Alpha isn't even like vax. PDP-11 and VAX were lighly
CISC machines where the alpha is vary RISC like. I'm sure PAL code
in the alpha could emulate PDP11 instructions and it would be very fast
but it would still be 16bit and to munge a large array the system would
have to map it into the 4mb max using MMU emulation.
<Now, making a VAX that would do that is a bit more interesting, though
<probably already done. VAX is much more useful these days than PDP-11.
Emulating PDP-11 on a 11/780 vax was a compatability bit and ran it
directly. For later vaxen RTEM ran PDP-11 programs on vax and generally
faster than the PDP11 (assuming the vax was faster itself).
<More on this subject: I have long thought that some computers that
<are now mostly PD, like the C-64, should be rebuilt in kit form and
<sold to kids for $20 each. Now THAT would be nice. Oh, and make them
<make their own kernel, and hold a contest for the best one. The
Get real, few if any are PD. The design is copyrighted or at least
the vendor specific portions(PROMS, PALS, custom LSI) are.
<>fits in the primary cache of an Alpha. If possible, you'd be using the
<Alpha
<>essentially as a programmable microengine and programming it to be
<PDP-11.
<>The reason to fit it in the primary cache is because of how the Alpha
<boots;
Huh? a PDP11 emulator for alpha would be written as PAL to get the best
results. Caching it is pointless as it's still a 16bit machine and
would still flog itself to death trying to manage a data file greater
than fits in ram (4mb max on PDP11 and some of that would be code!).
The point being, going to VAX(32bits) and later alpha(64bits) was not
raw speed but the limits of having enough bits to address really huge data
arrays in RAM and to express disk data addresses in values that fit in one
register. PDP-11 was 16bits and the MMU allowed it to may that 16bits
into 22bit address space. The however of that was at any time you could
only reach 16bit address worth of data or you had to remap the MMU.
That later step was a limiting factor if your data file was 32mb in size.
PDP-11s were fast and good but the limits of 16bit addressing were well
known by the late 1970s and that was why DEC moved to 32bit VAX in 1978.
Even then a really fast 11/70 could nearly outrun it unless the data file
operated on was say several megabytes in size and the VAX would leave the
11 behind everytime. If that weren't true we'd be running 500mhz PDP-8s!
Allison
On Apr 22, 23:01, Tony Duell wrote:
> > I thought of that too. Then you might be able to do it with an AOI
package,
>
> Oh, AOIs are fun, but not general enough for this...
You tend to need more than one small package to anything very useful
> > but I'd use a 156, which is a demultiplexer/decoder but with open-collector
> > outputs, which I'd wire-AND.
>
> Good guess. What you need is a fixed AND matrix to get all the possible
> product terms and then a programmable OR matrix to combine the right ones
> to form the desired output.
>
> That's _exactly_ what a PROM is, of course.
>
> It's also what a multiplexer is.
A neat solution. Of course, anything you can do with minterms can also be done
with maxterms.
> What worries me is that the above seems not the taught any more. And
> people don't seem to have grown up fiddling with TTL chips (or
> equivalent).
Here, 1st Year CompScis do a series of practical problem exercises with TTL,
one of which ends up building a multiplexer from basic gates. The next (or
maybe next but one) involves something that's complex to do with normal minterm
techniques, and often involves using a multiplexer as a building block.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
On Apr 22, 19:12, Allison J Parent wrote:
> LSI-11/03 cpu and box. The backplane was wired for only 16bit addesses.
> Also that particular CPU put some of the microcode signals on what would
> have ben the A16-21 lines.
Nitpick: Actually, it's wired for 18-bit (it has to be, for parity), and the
extra microcode signals are only on the A18-21 lines.
You can have fun with General Robotics backplanes/PSUs. Some of these put 24V
AC on the lines normaly used for A20 and A21.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
But, since Alphas must share SOMETHING in common with the PDP-11,
wouldn't it be possible to write a normal program for the Alpha,
running under NT or Linux, that would give PDP emulation at P-II-like
performance? Of course, I'm assuming that some of the PDP instructions
can go unchanged directly into the Alpha. Also, I would guess that a
G3 with an emulator could outperform the slower pentiums. But, then
again, why not emulate a Whirlwind or a Mark I for the same? It would
be much easier. I don't really see how an emulated PDP-11 outper-
forming a pentium would mean anything at all.
Now, making a VAX that would do that is a bit more interesting, though
probably already done. VAX is much more useful these days than PDP-11.
More on this subject: I have long thought that some computers that
are now mostly PD, like the C-64, should be rebuilt in kit form and
sold to kids for $20 each. Now THAT would be nice. Oh, and make them
make their own kernel, and hold a contest for the best one. The
winner gets an emulated PDP-11.
I really must stop eating sugar as well.
>incremented value) and three for JSR I Z 10 (fetch 10, write
incremented
>value, stash return address at location pointed to by incremented
value),
>so I could be wrong) each of which depend on the previous one. You're
not
>going to get hot performance out of that unless you decide that the
main
>memory can be built using a 5-port register file on the chip.
>
>I've occasionally wondered about doing a tight hand-coded PDP-11
emulator that
>fits in the primary cache of an Alpha. If possible, you'd be using the
Alpha
>essentially as a programmable microengine and programming it to be
PDP-11.
>The reason to fit it in the primary cache is because of how the Alpha
boots;
>at reset, it loads its primary cache from an external serial ROM and
begins
>executing it. If you could fit the emulator in the primary cache, you
could
>think of the Alpha+SROM as a PDP-11 microprocessor.
>
>Roger Ivie
>ivie(a)cc.usu.edu
>
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What would happen if we made a PC-sized PDP-11 processor using the Alpha
technology? (On a single chip, clock it at ~300-400 MHz)
As the PDP-11 instruction set is MUCH better than 80x86, would it outrun
a PC? Could this be a Pentium Killer?
-------
<>As the PDP-11 instruction set is MUCH better than 80x86, would it
<outrun
<>a PC? Could this be a Pentium Killer?
as it was in 1982-3 the PCversion of the PDP-11 aka PRO350 could eat
the XT and turbo XT for a snack. When the AT came around DEC popped
out the pro380 with the J-11 cpu...gulp, burp! ATs are tasty.
Competing against the mostly 16bit 8088/6 and the 286 the PDP11 was out
front. To match a 16bit cpu against a 32bitter... you must be inhaling!
Allison
After your done laughing remember this...
At the time the VAX was new in the market the PDP-11 group took most of
their standard 11/70 peices and cooked up the 11/74 which was a 4cpu SMP
11/70 and could eat vaxen(11/780) for snacks. That was it's demise...
there were only four working 11/74s built before that was crushed.
<Hmm, refresh my memory, now what were the PDP-11 instructions to
<directly address 4GB of memory? I can't seem to recall any 32 bit
<address registers.
Look in the VAX archectecture book.
<Darn. I've really lost it...how did the virtual memory hardware work in
<a PDP-11?
Nicely (again the vax is a mostly stretched 11).
<Seriously, if you mean the sorta RISC like instruction set in the 11 is
RISC?????? PDP-11 is the most CISC machine in the 16bit realm. What
other 16bitter is a two address orthoginal machine?
<better than the x86 set, then DEC probably would have come up with
<something like that. Course, with extra silicon, they could have gone
<to 64 bits, and put more cache onboard, then clock it really fast. Then
<come up with some catchy marketing name, like Gamma, or Beta, or ....
They did called it VAX and when it came time to outvax VAX then comes
alpha.
Allison
<Um... Am I way out here? Doesn't the 23 support 22 bit addressing? And
The basic M8186 early revs are 18bit but most work as 22bit, the later
revs were 22bit. That's assuming the backplane is wired for 22bit as
well.
<I never before heard of a 16 bit Qbus! ISTRT the F11 processor is
LSI-11/03 cpu and box. The backplane was wired for only 16bit addesses.
Also that particular CPU put some of the microcode signals on what would
have ben the A16-21 lines.
<settable between 18 and 22 bit (128KW, 256KB and 2MW, 4MB respectively).
<The 18 bit setting is used in the 23 on 18 bit Qbuses and in the 24 on
<unibuses. The 22 bit setting is used on 22 bit Qbuses, but you need
<extra hardware to use it in the 24 (i.e. on unibus).
Your thinking of latter machines with specific backplanes.
Allison
> What would happen if we made a PC-sized PDP-11 processor using the Alpha
> technology? (On a single chip, clock it at ~300-400 MHz)
> As the PDP-11 instruction set is MUCH better than 80x86, would it outrun
> a PC? Could this be a Pentium Killer?
I doubt it could be a Pentium killer, but I could be wrong. The RISC
machines get performance by making it difficult to go to memory; on the
PDP-11, it's much to easy to go to memory.
Take, for example, the PDP-8. The worst-case instruction on the PDP-8
could require as many as five memory accesses (hmm; I forget which one
took five. I only count four for ISZ I Z 10 (fetch 10, write incremented
value, fetch from incremented value, write incremented value pointed to by
incremented value) and three for JSR I Z 10 (fetch 10, write incremented
value, stash return address at location pointed to by incremented value),
so I could be wrong) each of which depend on the previous one. You're not
going to get hot performance out of that unless you decide that the main
memory can be built using a 5-port register file on the chip.
I've occasionally wondered about doing a tight hand-coded PDP-11 emulator that
fits in the primary cache of an Alpha. If possible, you'd be using the Alpha
essentially as a programmable microengine and programming it to be PDP-11.
The reason to fit it in the primary cache is because of how the Alpha boots;
at reset, it loads its primary cache from an external serial ROM and begins
executing it. If you could fit the emulator in the primary cache, you could
think of the Alpha+SROM as a PDP-11 microprocessor.
Roger Ivie
ivie(a)cc.usu.edu
Seth and Pete were discussing the PDP11-23...
>> 2) Same as above, but for the M8044-DB boards. I could put one
>> of these in with the M8047's to get a full 64Kword of RAM, yes?
>> Does anyone know what the DIP-switch settings for these boards
>> are?
>
> Yes, but I'm not sure why you say "full" and 64Kword" together :-)
> 32KW (64KB) is the limit for 16-bit addressing, or 128KW (256KB) for 18-bit
> addressing. Ignoring the I/O page, that is.
Um... Am I way out here? Doesn't the 23 support 22 bit addressing? And
I never before heard of a 16 bit Qbus! ISTRT the F11 processor is
settable between 18 and 22 bit (128KW, 256KB and 2MW, 4MB respectively).
The 18 bit setting is used in the 23 on 18 bit Qbuses and in the 24 on
unibuses. The 22 bit setting is used on 22 bit Qbuses, but you need
extra hardware to use it in the 24 (i.e. on unibus).
Just my half groat's worth.
Philip.
On Apr 22, 1:57, Tony Duell wrote:
> Jack Peacock wrote:
> > 'No, I can do it with a normal 16 pin TTL chip that doesn't have to go
> > in a programmer first'. So, what was the chip ?
> >
> > 74LS138, 1 of 8 decoder, the three inputs go to A, B, C, all 8
> > possibilities decoded on the outputs.
>
> Alas not.. I didn't want the 8 separate combinations of the 3 input
> variables - I wanted a single output that was a complex function of them
> - something like A.C + A.B/ + A/.C/.B or something...
I thought of that too. Then you might be able to do it with an AOI package,
but I'd use a 156, which is a demultiplexer/decoder but with open-collector
outputs, which I'd wire-AND.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Sure. And then Apple would show our mascot, Barney, in flames.
I like this already!
>
>What would happen if we made a PC-sized PDP-11 processor using the
Alpha
>technology? (On a single chip, clock it at ~300-400 MHz)
>As the PDP-11 instruction set is MUCH better than 80x86, would it
outrun
>a PC? Could this be a Pentium Killer?
>-------
>
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<are there any good sites out there containing collections of schematics
<for old machines? I occasionally come across sites with a few schematics
No.
<interest in this? I was thinking more along the lines of some of the
<more obscure hardware out there though, as there's probably plenty of
<places to get details on common machines such as the popular 8-bit
<micros of the early 80's. Would be nice to have copies of ROM/Disk
<images where possible too...)
There is the problem of copyrights and permission. Not as easy as you'd
think as the copyright live past the companies demise so you have to
track where or who still holds it.
Allison
As the PDP-11 instruction set is MUCH better than 80x86, would it outrun
a PC?
-------
Hmm, refresh my memory, now what were the PDP-11 instructions to
directly address 4GB of memory? I can't seem to recall any 32 bit
address registers.
Darn. I've really lost it...how did the virtual memory hardware work in
a PDP-11?
Seriously, if you mean the sorta RISC like instruction set in the 11 is
better than the x86 set, then DEC probably would have come up with
something like that. Course, with extra silicon, they could have gone
to 64 bits, and put more cache onboard, then clock it really fast. Then
come up with some catchy marketing name, like Gamma, or Beta, or ....
Jack Peacock
I have C-64 ones. You could attach a gender changer to the koala
pad if it has an Apple plug, and use it on a Commodore.
>Does anyone have the disks for the paint program that came with the
Apple
>Koala pad?
>
>Thanks
>
>manney(a)lrbcg.com
>
>
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<PROM, or maybe one of those TI PALs with the 74-series numbers'. I said
<'No, I can do it with a normal 16 pin TTL chip that doesn't have to go
<in
<a programmer first'. So, what was the chip ?
<
<74LS138, 1 of 8 decoder, the three inputs go to A, B, C, all 8
<possibilities decoded on the outputs.
< Jack Peacock
How about 74153 or 74155 real handy for creating complex miniterms that
a small prom or pal might be used for.
Allison
<> =============================================================guide rai
<> +
<> +
<> +
<> +
<> +++++++++++++++++++++++++++ <<<<<<<direction of motion (96 needed)
<> ^ +
<> | +
<> / +
<> | +
<> |=============================================================guide rai
<> ^optos to read the leading edge of the card for column clock, spacing
<> is such that each one is obscured as the column is over the column
<> leds making it self indexing. It's possible to go very fast.
<
<Now that I like!. I wonder where I can find some cheap photodiodes.
<
<What about one of the CCD (or similar) linear image sensor chips? They're
<quite cheap in surplus shops now, I think... A bit of optics to focus the
<image onto the sensor, and a bit of electronics to drive it (which is not
<that hard to design).
CCD needs a fair amount of electronics, photo transistors are cheaper and
simpler. Jade, JAMCO, JDR and BG micro list phototransistors pretty
cheap.
Allison
>(Cautiously, looking around). Is all the nastiness over, now?
Been over for weeks. It seemed to merely be 'growing pains.'
>Does anyone have the disks for the paint program that came with the Apple
>Koala pad?
I remember hearing that it should work with any app that supports mice.
Glad to have you back. (I was wondering where the heck you were.)
Tim D. Hotze
(Cautiously, looking around). Is all the nastiness over, now?
Does anyone have the disks for the paint program that came with the Apple
Koala pad?
Thanks
manney(a)lrbcg.com
> > panel monitor used an octal keypad & display, and the octal thinking
carried
> > over to the assembler package. Heath also used "split octal" in the
fashion
> >
> Actually I think Octal is a dumb idea for 8 or 16 bit processors :-) -
A side note...on the IMSAI front panel the address/data switches came in
two colors, red and blue, so you could group them for hex or octal
inputs. (Obscure trivia, the prototype IMSAI used black switches.) You
could tell just by looking at someone's front panel if they preferred
hex or octal. Mine is in hex, S/360 Assembler was the first assembly
language I learned, and it was in hex.
If I recall correctly, Microsoft was an early user of split octal. Soon
after the 4K/8K BASIC, MS came up with an editor/debugger package for
Assembler that used the split octal notation (fuzzy here, does anyone
else remember that package, it was short-lived).
Octal proved useful in suprising ways. On Seymour Cray's CDC 6000
series, with a 60 bit word, you might think that a dump using 15 hex
digits per word would be the most useful, but in fact that was never
done, because the 60 bit word was broken down into 15 and 30 bit
instructions (multiple instructions per word, a Cray innovation I
believe), easy to see in octal but not a good fit in hex. Plus, the
character set normally used was 6 bit, not 7 or 8 bit ANSI.
Jack Peacock
