
Commodore 900 - derriz
http://www.floodgap.com/retrobits/ckb/secret/900.html
======
Jerry2
This page has a lot more photos including manuals:

[https://datamuseum.dk/wiki/Commodore/CBM900](https://datamuseum.dk/wiki/Commodore/CBM900)

The part about the OS caught my eye:

>Commodore chose the Mark-Williams "Coherent" clone for the CBM900 which is
roughly UNIX System 7, but with a few twists and less features.

>The operating system is delivered on four floopy disks: Low-res and Hi-res
boot, and common volume 2 & 3 with more programs. All four floppies contain a
filesystem. We have made bit-for-bit images of these floppies, both on the
CBM900 harddisk and offline.

~~~
smacktoward
If you’re interested in Coherent, you can get some background on it and even
download the source code here:
[http://www.nesssoftware.com/home/mwc/](http://www.nesssoftware.com/home/mwc/)

And here’s a 1998 thread from the Usenet group alt.folklore.computers where
Dennis Ritchie (!) recounts his experience of being sent by AT&T to evaluate
whether Coherent violated their Unix copyrights:
[https://groups.google.com/forum/m/#!msg/alt.folklore.compute...](https://groups.google.com/forum/m/#!msg/alt.folklore.computers/_ZaYeY46eb4/5B41Uym6d4QJ)

~~~
jcims
Wow never thought I'd hear about this OS again. I still have the original
manual and discs in the basement. My dad bought it and tinkered with it on a
this huge Epson 386 back in the day...I got to the point of X without a window
manager and gave up lol.

~~~
jacquesm
Some fun facts to get your head wrapped around:

[https://en.wikipedia.org/wiki/Mark_Williams_Company](https://en.wikipedia.org/wiki/Mark_Williams_Company)

That's Aaron's dad.

------
jacquesm
When reading these kind of articles it always strikes me as odd that we had
such a huge problem to stabilize systems running on as little as a few MHz and
now we have GHz machines that are relatively solid performers. The first time
I built a system with a base clock above 16MHz it took all kinds of rituals to
keep the system running good enough to get some use out of it.

~~~
rasz
If you put a scope on old commodore computer buses you will quickly realize
the reason. You might expect digital signals with somewhat clean edges, in
reality its all barely working analog mess with tons of "maybe if I put a
resistor/cap/inductor here" hacks and production fixes.

Bil Herd talks about it sometimes when reviewing his old designs
[https://www.youtube.com/watch?v=xPD5N43VIsk](https://www.youtube.com/watch?v=xPD5N43VIsk)

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CmdrKrool
Coincidentally this video just popped up in my Youtube feed: "Before Amiga:
The Story of the 16-bit Commodore 900"
[https://www.youtube.com/watch?v=5OpI87v6OqA](https://www.youtube.com/watch?v=5OpI87v6OqA)

It asserts that the 900 was an initiative by the German wing of the company,
and that the Zilog CPU was considered a strange choice, in the circumstances.

~~~
phkamp
I was employed by Commodore Denmark in 1984 to become their UNIX wizard for
the CBM900, and I'm part of datamuseum.dk.

The 900 was very much a US project, Germany wanted the PCs.

The C900 prototypes were manufactured in Germany however, but that was simply
because they had the facilities for the large PCB's from the 8xxx series.

~~~
walkingolof
So the Germans took the case and created the Amiga 2000 (?)

~~~
mjg59
I believe the case design came from Commodore's PC range, which was largely a
German initiative. The A2000 was designed in Germany and never launched in the
US - Commodore US designed their own system around a slightly reworked chipset
which ended up as the B2000 (which used the same case)

------
mjg59
There's a bunch of coverage of the C900 and the historical context of
Commodore at the time in Commodore: The Amiga Years. Amazon has it in
hardcopy, or you can get the ebook version at [http://variantpress.com/the-
amiga-years-kickstarter/](http://variantpress.com/the-amiga-years-
kickstarter/). I literally finished reading it last night, and there's an
amazing amount of detail I've never seen anywhere else.

------
reaperducer
I noticed that the 900 had the ability to be used as a timeshare machine. I
wonder if this was one of the last timeshare machines. Or maybe the concept
continues in the supercomputing realm.

~~~
rjsw
Any Linux system is a timeshare machine.

~~~
myrandomcomment
The context of the question was this the last machine designed to be a time
sharing machine, ie it had hardware directly on it for the express purpose in
design to be used for terminals.

I do not think so but the meat memory storage is not working fully right now.
I do know that things (not a PC type) like the AS/400 had physical terminal
connectors well after this.

------
masswerk
From floodgap.com:

> _The Commodore 900 (…) was intended as a mainframe-class machine with
> multitasking, timesharing, virtual memory, multi-user capabilities — what
> you would expect from a Typical Un#x Mainframe. System adminstration was
> accomplished through an X-Windows-like GUI on the workstation version of the
> 900; the text-only server flavour could be used as a workstation but was
> intended to be a standalone host._

> _project officially discontinued in favour of the newly-acquired Lorraine,
> later becoming the Amiga._

When Commodore refrained from becoming an actual computer manufacturer…

~~~
cmrdporcupine
They didn't learn the lessons from the C64 which was a runaway success. No
effort to make a product line with forward compatibility. Minimal effort on
software. Bizarre pricing strategies.

At least with Tramiel at the helm they had a strategy of going for the long
tail of the market by selling at rock bottom prices. Once he was gone they
floundered around, and almost got beaten by Tramiel's Atari. It's only once
they release the Amiga 500 -- which looked an awful like the 520ST case and
strategy wise -- and dropped the price that they caught the lead.

When I bought my ST the 500 wasn't out yet, and the Amiga 1000 was priced way
beyond my budget. The 520STfm I bought with monitor was around the same price
as the Commodore 128, which I was considering before I discovered the ST.

~~~
rasz
Tramiel had a habit of firing good engineers 3 months after product release.
Either directly, or by screwing them by moving to useless positions or taking
bonuses away until people 'got the message'. Those who didnt get what was
going on or didnt care about money/dignity were the ones who stayed as long
term employees. Jack had an eye for suckers and people putting passion before
common sense and self respect.

Whole C64 design team was effed out of promised bonuses and fired/left. People
like Bruce Crockett (manufacturing), Al Charpentier (VIC) and Robert Yannes
(SID) went to start Ensoniq (later sold to Creative), Chuck Peddle went to
Apple, Bill Mensch hung around for two years of abuse. Same with Amiga team
(Jay,RJ,Needle).

Those two videos touch on the Commodore culture of curb stomping until only
the weak and dumb survive:

Oral History of Chuck Peddle
[https://www.youtube.com/watch?v=enHF9lMseP8](https://www.youtube.com/watch?v=enHF9lMseP8)

Oral History of William David "Bill" Mensch Jr.
[https://www.youtube.com/watch?v=Ne1ApyqSvm0](https://www.youtube.com/watch?v=Ne1ApyqSvm0)

~~~
cmrdporcupine
That's interesting, though your example of the Amiga team -- they weren't
there under Tramiel, so would have nothing to do with him in particular.
Though I'm sure the culture there was rotten.

~~~
vidarh
That's true, a lot of the problems came down to Irving Gould - Tramiels main
investor. While Tramiel was there they appear to have countered each others
flaws just enough for things to mostly work. After Tramiel, Gould went through
executives in short order, and most of them had no idea how to properly
leverage what Commodore had.

That said, Tramiels last pricing stunt (drastically dripping the price without
preparing the distribution chain, and so hanging them out to dry) also
contributed to gutting Commodores distributor network in the US in a way they
never really managed to fix.

