Re: CBM900 to SVGA monitor

This might not be the commodore 900 that it was designed for, supposedly 
there were three projects.

1. Didn't get anywhere after having a lot of time and money poured into it.
2. Disappeared along with schematics etc when Jack left and shortly 
afterwards the ST prototypes appeared. After Commodore sued Atari for 
walking out with intellectual property, jack found the Atari 1850XLD 
contract and sued Amiga (now commodore) for breaching that (separate issue 
from the loan Atari gave to Amiga which is the story that was going round). 
Both cases were settled out of court.
3. George Robbins and Bob Raible did the one that everyone knows while 
commodore were wondering what they should be doing. The answer turned out to 
be buying the Amiga so it got cancelled. Some machines made it out for early 
Amiga software development using cross assemblers/compilers until native 
tools existed, which is why "so many" are still around.


I got the impression the 8563 came out of the failed project and might have 
been disregarded by George & Bob.

http://www.floodgap.com/retrobits/ckb/secret/900.html

"The Z-Machine guys (in two generations; the first designers, having failed, 
turned development over to the second team of George Robbins and Bob Raible 
[Dave Haynie]), were paragons of lunacy according to Bil Herd; the only 
things to survive from that project, besides the 8563 (the 8563 is a story 
in futility in itself; its misadventures in the 128's development cycle are 
in the entry for the D128), were a strange disk controller that asked for 
the desired sector and cylinder on every access (though Joe Forster/STA 
points out that IBM mainframes do much the same thing for disk access as a 
way of facilitating multitasking), and a legendary practical joke where the 
900's engineers stole the furniture from the Commodore office lobby and made 
their own lounge disguised as a VAX repair depot."


Two variants of commodore 900 were planned, but I'm not convinced that the 
server version would have had an 8563 in it. My guess is you either bought 
the workstation version with a built in graphics card (which the specs are 
too high for an 8563), or you bought the server version that had no display 
hardware & they only ever planned on using the 8563 in a dumb terminal.

http://www.floodgap.com/retrobits/ckb/secret/900.html

"Graphics and Sound Two versions, according to Peter Kittel; the graphics 
version was 1024x800 monochrome (72Hz refresh on the monitor) and intended 
as a workstation; the server variant was character display only. Graphics 
powered by the 8563 VDC."

"According to Jim Brain, the 8563 (designed as a colour 6845; it became the 
128's 80-column video chip) was intended and designed for the 900s, but of 
course the 8563 has plenty of applications beyond that. In fact, an fragment 
of an E-mail I ran across from Dave Haynie mentioned that the 8563, in tow 
with a sidecar CPU (undoubtedly a 6502 in some form) and ACIA (6551?), was 
to be the centrepiece of cheap multi-user terminals set up around the CBM 
900 -- no less than glorified 6502-based Xterms. Clever! The article Anthony 
furnishes above also mentions an integrated terminal, which may or may not 
be the same thing, but it does talk about an optional multi-user card with 
eight additional RS-232 ports which was undoubtedly the core of this idea. 
Whether this card got finished is another story altogether. "


The history is pretty vague, it was a long time ago and the survivors appear 
to have spent most of that period in a bar getting drunk. I doubt they 
expected there would be a test thirty years later.

-----Original Message----- 
From: Gerrit Heitsch
Sent: Thursday, July 24, 2014 7:59 PM
To: cbm-hackers@musoftware.de
Subject: Re: CBM900 to SVGA monitor

>
> * Surprisingly, there is no 8563 chip in the card. The whole card is
> built around TTL chips: http://imgur.com/kIgNsHi

Well, the 8563 is the incarnation of the VDC with the 6502 bus
interface. And while they said that the VDC was designed for the CBM900,
I haven't been able to find out if they ever had working silicon or were
only in the design stages as it the 900 canceled.


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