Re: Tempest Pincushion and Vector Info

Kirk Spradling wrote:
> Here it is: http://www.jmargolin.com/
>
> Interesting stuff; even after reading about the State Machine, I'm lost...

You might also find this interesting:

http://www.philpem.me.uk/blogfiles/vecgen.pdf

A couple of years ago, I reverse-engineered the Atari Digital Vector Generator
(that is, the B&W one used on Lunar Lander, Asteroids and possibly a few
others). The problem at the time was that there was no usable instruction set
data... so I printed out the Asteroids schematics, Scotch-taped them together,
and started stepping through the state machine.

It took me about a day to figure out enough of the state-machine logic to be
able to document it. I spent the rest of the week actually documenting it :)

Anyway, it's worth a read if you're interested in the gory details of the
DVG's operation. If you're interested in the AVG (Star Wars et al) then
someone scanned a document that was found in a skip at Atari Tipperary. I
think the site was called "secrets of Atari" or something along those lines.
That document contained information on the AVG, from a rough outline of the
AVG architecture to the instruction set and state machine logic.

I think I might still have my Verilog implementation of the DVG, somewhere.
Built to run on a pair of Xilinx XC95288XL CPLDs -- one for the state machine
logic, the other for the vector counters and so on. I never did get around to
building that thing...

Thanks.

-- 
Phil.
lists@philpem.me.uk
http://www.philpem.me.uk/
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