Commodore 900 | Hacker News Reader

Commodore 900

floodgap.com

102 pointsderriz41 comments

This page has a lot more photos including manuals:

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.

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/

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...

In the early 90's I used to run Coherent on a 386SX. It was my first exposure to a "Unix clones." It had one of the better Unix manuals for the time... very comprehensive. I later moved to Linux probably 1993-ish.

Almost bought it to operate a multiline BBS. The $99 price for a Unix like OS was astonishing. IIRC, my fellow SysOps and I ended up not going that route after contacting the company about the possibility of Coherent running PicoSpan and were told it likely wouldn't fit into the memory space. So we ended up using MajorBBS instead, which worked out fine.

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.

Some fun facts to get your head wrapped around:

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

That's Aaron's dad.

Funny, I just realized something. Remember the Commodore 64? My brother used to call it CBM64, and his initials are BM, so I thought it was C for Commodore + his initials + 64.

And now, looking at CBM900, I got a hint that CBM could have been something else. Quick google search, and I see that it's "Commodore Business Machines", probably inspired by IBM (International Business Machines).

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.

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

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

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.

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.

Come to think of it, I was employed by Commodore (Danmark) A/S precisely 35 years ago this week.

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

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)

To be totally honest, I have no idea what order things happened in there, but it would be very Commodore like to reuse the molds for the plastic that way.

We have never compared the C900 physically to the A2000 in datamuseum.dk, we should do that some day.

Commodore had done other Z80 products I seem to recall some expansions that allowed running CP/M as well as that native PET OS

Apple Had a z80 card for the Apple ][ as well I rembered

The C128 had a z80 and could run CP/M.

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/. I literally finished reading it last night, and there's an amazing amount of detail I've never seen anywhere else.

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.

Any Linux system is a timeshare machine.

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.

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…

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.

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

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

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.

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.

Commodore went from being hostile and ruthless (but profitable and successful!) under Tramiel to plain stupid under Rattigan to corrupt under Mehdi.

By and large, Commodore invented the "double-burger" tax-shelter, and discovered to their dismay that it was very hard to funnel the "liberated" money back into the company for investments.

The lack of a vision going forward also caused local projects to suck up too many resources, Germanys PCs, the C16/+4 disaster and so on.

They acquired a machine that quite a few people consider an actual computer http://www.floodgap.com/retrobits/ckb/secret/lorraine.html

But, again, Commodore refused to market it is a "serious" computer (while the platform may have arguably been superior to the IBM PC.)

Edit: The sad story being that Commodore marketing apparently was happy with merely selling in the home computer market, where Commodore machines sold seemingly by them selves, and didn't bother to bare the hassles of the competition of the business market. – Which eventually resulted in the end of the company.

Even when Commodore and Atari attempted to market their 68000 machines as serious machines they were given no respect by the press. Both made a concerted effort in the late 80s early 90s to make workstation class machines and sell them into the expanding Unix workstation market, and had no success.

I distinctly remember picking up a copy of UnixWorld in about 1990 or so and seeing an Atari TT030 in it, with the caption "up from toyland" and a couple paragraphs describing the specs of the machine as being workstation class and it shipping with AT&T Unix and it being cost effective but how could anyone take it seriously coming from a home computer and games maker? That was the start of the last couple years for Atari and Commodore, they were both done soon after. Apple barely survived.

This is correct. The problem wasn't that the Atari and Commodore 68000 machines weren't "serious" computers. It's that they had the wrong pedigree.

CBM and Atari made powerful machines that came "up" from the home computer market. IBM made underpowered machines that came "down" from a mainframe manufacturer. It was an easy choice for PHB's to go with Big Blue. As they used to say: "Nobody ever got fired for buying IBM."

How Apple survived was something of a miracle. My impression is that it was because it gained early traction in certain industries with the first mass-market WIMP machine, and retained some air of "seriousness" because pre-IBM PC, 8-bit Apples were the "serious" business machine for the vast majority of companies. (Think 90,000 accountants all banging out VisiCalc* sheets.)

*The fact that iOS just auto-corrected my spelling of VisiCalc in 2019 makes my inner nerd smile.)

Apple survived into the 90s on the back of the education market, primarily with Apple 2 and 2gs systems, secondarily with Macs. IIRC it was hard to find CBM or Atari systems to play with (you could go into a BusinessLand or ComputerLand and play with Apple 2gs or Macs or IBM PCs or Compaqs, vaguely recall Atari had some sort of distribution deal with Sears).

Commodore was always weak in the US, and strong in Europe, while Apple was the reverse. Growing up in Norway,the first Apple product I ever saw in person was the single Mac classic my local computer store put in a corner and neglected, while Commodore 64s, 128s and Amigas,Atari STs , Spectrums and Amstrads were all over the place.

The precise set of brands that did well varied a lot by country, but Apple did poorly in most of Europe until the Mac started getting traction, and Commodore did well in most of Western Europe.

Part of it was that Tramiels US price war stunt figuratively burned Commodores US dealer network to the ground, but when before that done European markets, particularly Germany did far better.

Commodore was at one point one of the best known consumer brands in Germany, irrespective of category. Somewhat less so in Europe as a whole, but still a name mentioned alongside IBM etc by people who had no idea who Apple were.

I don't remember the Atari TT030 as being easy to buy. I had been developing on STs since the initial developer offer but have never seen a TT.

Commodore (or rather, the CBM brand) did have quite a standing in the European business market, especially in Germany. It may be argued that Commodore was rather letting this run as a niche segment than building strategically on this and the respective distribution channels, which were already established. Eventually, this segment starved to a non-dramatic end, for the lack of new products, or products introduced half-heartedly.

Regarding Atari, it's a not too well known historical footnote that IBM was considering to acquire Atari's computer division, when IBM gave up their various efforts of introducing a consumer machine of their own in the late 1970s. (There's even an "IBM-Atari" design prototype by Tom Hardy.) A broader knowledge of this may have changed Atari's image quite dramatically.

It found a niche in a serious industry (video). Commodore simply got ran over by WinTel. They forgot one big part of their success was low cost and being available in a large number of outlets. They didn’t have a cost successor to the C64. The 900 was not that either.

That is very far from the truth, and the truth was nowhere as simple as that either.

Commodore was a very serious and successful supplier of small business computers with the 8xxx and 82xx series.

The main problem was that in this segment Commodore came out of a typewriter/calculator mindset, so there were absolutely nobody who ever thought "lets connect computers together", and that set a hard upper ceiling how how large companies they could sell to.

Once a business grew, the CBM computers were replaced, not because they were unhappy with them, but because they were not big enough.

Heck, even at Commodore we used IBM S/34 internally.

See my earlier comment on this below. In Europe, the PET had been pretty much what the Apple II had been in the US. It is heart shattering how Commodore/CBM was unable to exploit this position (e.g., by providing an upgrade path to the next level) – whatever the internal dynamics behind this.

The reason the C900 were cancelled was that Commodore simply didn't have the resources (money, facilities) to do both that and the Amiga.

Yeah, George Robbins stopped working on the C900 and went on to design the A500, A600 and A1200, sticking references to songs by the B52's on their motherboards. A lot of people don't realize that Commodore had about 200 engineers at peak.

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