I have a Decitek 442A9 papertape reader which needs repair.
I have already replaced the belt, but that is not enough. The reader behaves very strangely. It
starts running as soon as I apply power. And there is another problem: when I load a tape, it
rattles irregular during reading. This is not a mechanical problem, it seems to react to the pulse
of the feed hole, which arrives at the wrong time.
I'm pretty sure, that I have to adjust the sprockets somehow relative to the stop positions of the
stepper motor.
It was nothing to be found online except pictures of a similar model 443A9 at RICM:
https://www.ricomputermuseum.org/collections-gallery/equipment/dec-pdp-8s-4.
The controller board number is 30291A
Does anyone happen to have the manual and/or schematics or any other documents?
Thank you,
Micha
Turbo-Pascal was quite popular. At the annnouncement of it (West Coast
Computer Faire), Phillipe Kahn (Borland) was so inundated with "yeah, but what
about C?" questions, that by the end of the first day, "Turbo C is coming soon"
With the VA dropping Vista what happens to that army of Mumps
programmers they had? Can't see much call for them in the IT
world today. Seems like a worse fate than COBOL Programmers.
bill
Nostalgia keeps pressing ahead: It was 60 yrs. ago that BASIC came into
existence. I remember very well writing in Apple Basic and GW Basic later
on. As a non-compiled OS, an interpreted OS, it was just the right tool for
a microcomputer with limited memory. I recall fondly taking code from
popular magazines and getting them to run. It was thrilling indeed!
Happy computing,
Murray 🙂
In the early '80's, I did some programming with Micro Concurrent Pascal,
on embedded CDP1802 systems. It was really nice to be able to program in
something other than assembly language (a cross-assembler that ran on a
PDP-11 system).
Regarding protections, it didn't have many. I remember spending a day
tracking down a fatal bug with a logic analyzer (emulators were still a
dream in this small company)... another programmer had used an array
subscript out of range and the compiler didn't catch it for some reason.
So in this array defined [0..20], when the typo caused a write to
FOO[60] instead of FOO[20], bad things happened.
Ah, the good old days ;)
-Charles
PL/M (think "PL/1") was a high level programming language for microprocessors.
CP/M was also briefly called "Control Program and Monitor"
It was written by Gary Kildall. (May 19, 1942 - july 11, 1994)
Gary taught at Navy Postgraduate School in Monterey.
He took a break in 1972, to complete his PhD at University of Washington.
He wrote 8008 and 8080 instruction set simulators for Intel, and they loaned
him hardware.
In 1973? he wrote CP/M.
He offered it to Intel, but they didn't want it, although they marketed the
PL/M.
He and his wife started "Intergalactic Digital Research" in Pacific Grove.
Later renamed "Digital Research, Inc."
CP/M rapidly became a defacto standard as operating system for 8080 and later
Z80 computers.
In the late 1970s, when CP/M computers were available with 5.25" drives, and
there were hundreds, soon thousands of different formats, I chatted with Gary,
and pleaded with him ot create a "standard" format for 5.25".
His response was a very polite, "The standard format for CP/M is 8 inch single
sided single density."
I pointed out that formats were proliferating excessively.
His response was a very polite, "I understand. Sorry, but the standard format
for CP/M is 8 inch single sided single density."
In 1980? IBM was developing a personal computer. (y'all have heard of it) One
of the IBM people had a Microsoft Softcard (Z80 plus CP/M) in his Apple. IBM
went to Microsoft, to negotiate BASIC for the new machine, and CP/M.
Bill Gates explained and sent them to Digital Research.
When the IBM representatives arrived, Gary was flying his plane up to Oakland
to visit Bill Godbout. He hadn't seen a need to be present, and assumed that
Dorothy would take care of the [presumably completely routine] paperwork. While
visiting Bill godbout, and delivering some software was important, it WAS
something that a low level courier could have done.
There was a little bit of a culture clash.
The IBM people were all in identical blue suits.
The DR people were in sandals, barefoot, shorts, t-shirts, braless women, with
bicycles, surfboard, plants and even cats in the office,
The IBM people demanded a signed non=disclosure ageement before talking.
Dorothy Kildall refused.
When Dorothy got Gary on the phone, it is unreliably reported that he said,
"well, let them sit on the couch and wait their turn like the rest of the
customers."
It is also been said that DR people upstairs saw the IBM people marching up,
and thought that it was a drug raid. I have stood in that bay window
overlooking the front door, and can believe that.
IBM chose to not do business with DR and went back to Microsoft.
When billg was unable to convince them that Microsoft was not in the operating
system business, Microsoft went into the operating system business. They
bought an unlimited license to QDOS (Tim Paterson's work at Seattle Computer
Products). They also hired Tim Paterson.
DR was working on CP/M-86, but it was a ways off.
Paterson had written QDOS ("Quick and Dirty Operating System") as a placeholder
to be able to continue development while waiting for CP/M-86
We've mentioned before, that Tim Paterson got the idea for the directory
structure from Microsoft Standalone BASIC. As Chuck pointed out, that was not
a new invention, merely a choice of which way to do it.
billg knew how to deal with officious managers. It is unreliably said that he
told the Microsoft people, "Everybody who does not own a suit, stay home
tomorrow!"
IBM insisted that Micorsoft beef up security. window shades, locks on doors
that normally weren't, locks on file cabinets, etc.
It is unreliably said that to throw off anyboy who heard about it, that
Microsoft referred to the IBm project as "Project Commodore"
dr continued to sell CP/M.
When the 5150/:PC was ready, IBM announced it with PC-DOS, which was a renaming
of MS-DOS,renaming 86-DOS, renaming QDOS.
If I recall correctly theprice was $40 (or maybe $60?)
DR pointed out that NS-DOS was extremely similar to CP/M.
https://www.cs.drexel.edu/~johnsojr/2012-13/fall/cs370/resources/An%20Insid…
IBM didn't consider it a problem, andsimply offered to ALSO sell CP/M-86,
particularly since they were already also marketing UCSD P-System.
CP/M-86 was not available yet, so everybody buying a disk based PC bought
PC-DOS.
But, most of us assumed thata CP/M-86 would become the standard once it came
out, and PC-DOS was similar and let us use the machines while waiting.
CP/M-86 took a long time to come out (6 months is a LONG time in such things).
When it did, the price was $240.
There are disagreemnets about whether DR or IBM had set the price point.
Most decided to keep using Pc-DOs until CP/M-86 had caught on.
But with the price differential, and the lead, PC-DOS remained the standard.
dr continued, came out with MP/M-86, and eventually came out with "Concurrent
DOS", and "DR-DOS", which was based on MS-DOS.
Microsoft could not fault somebody for copying them, when it was the ones that
they had copied.
No, Microsoft could certainly not claim trademark status for "DOS"!
In fact, although Microsoft trademarkd "MS-DOS", IBM did NOT trademark PC-DOS,
saying that it just meant Personal Compter Disk Operating System, which is a
description, not a unique name. In 1987, I visited the Patent and Trademark
Office outside of Washington, DC, and personally confirmed that in their
stacks.
Many people have said that blowing off IBM was the stupidest move in the
history of stupid moves.
Other people insist that blowing off IBM was the BRAVEST move in history.
A lot of people gave Gary flack about it.
eventually, he bagan drinking.
On July 8, 1994, Gary fell and hit his head. It is unclear whether that was
during an altercation. (A lot of people fall during bar brawls) It was at the
Franklin Street biker Bar & Grill, Investigation as a potential homicide was
inconclusive.
About 10 years ago, I was in Pacific Grove, and visited the DR house on
Lighthouse street. An extremely hospitable fellow had recently bought it in a
foreclosure sale. At the time that he bought it, he was unaware of the
historical significance. He let me wander through the whole place, looking out
the upstairs window at the walkway, etc.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
On Fri, 10 May 2024 12:00:07 -0500
cctalk-request(a)classiccmp.org wrote:
> The UCSD shell was atrocious. The compiler was slow. The editor was
> terrible. The entire experience was reminiscent of working on a dumb
> terminal connected to a mainframe, when it could've taken advantage of
> the features of the personal computer.
>
> I hated it.
>
> I hate it.
I've never had the pleasure, but a glance over the documentation is...
enlightening. God only knows why so many people over the decades have
gravitated to the "pick the thing you want to do from this list of the
things which can be done" school of UI design...
After 'lunch with Draper', you almost immediately reference a 'CRUNCH'
utility? Seems like more than coincidence to me, but I'm big on
conspiracy theories.
The Vintage Computer Federation is looking for a new bumper to add to the
front and back of all their new videos.
There are 7 different versions. Vote on the one that you like best!
https://forms.gle/Y9Qrj26xokeFXjub6
