Re: AVG chip replacement

On Thu, 10 Jul 1997 16:34:51 -0800 Clay Cowgill <clay@supra.com> writes:

>Thanks to an anonymous "little-birdie" that landed on my shoulder I
found
>myself with enough information to create a TTL equivalent of the Atari
>"AVG" chip as used in Star Wars, Space Duel, Quantum, etc... (It's the
>"VRAM Addresser" chip that runs the stack and program counter and some
>other stuff...)

All hail Clay! All hail Clay! The hacker supreme! (with some well
deserved credit to the birdie as well)

>The only gotcha is that there are a lot of chips in the design, and thus
a
>lot of PCB real-estate, and thus a higher cost per board. :-(

Just how big is the daughterboard that would plug into the socket?

>I can now produce "daughtercard" replacements for about $25 a pop as a
"bag of parts".

>The question at hand is-- is it worth it for that? I'll need to do
about
>30 boards at once to make the $25 price point...

I'd be interested in one (possibly two) as one of my projects is to get a
Space Duel going that some philistine attacked with a hammer. This attack
destroyed the CPU, AVG, POKEYs, multiple RAMs and misc TTLs. I swore that
I'd fix this board and see the bastard rot in hell.

I would be more interested in the bare boards as I recently stripped a
mess of 74LS TTL chips from some junk boards but I concede Clay deserves
something for cooking up the solution.

BTW How much would a PLD solution run for the same circuit? I remember
you saying the PLD would be more than the TTL method but how much?

That and he probably has a TTL supply that makes my junkbox look like the
IC selection at Radio Shack.

Virtu-Al
Received on Sat Jul 12 16:18:02 1997