[Coco] Am9511 Arithmetic Processing Unit Cartridge Pak for the Color Computer

[Don Barber]

Thanks so much for the kind words Mark, Richard, and David. I know an 
APU is probably not the most attractive peripheral for the CoCo 
community but it was a fun project that involved a few technical hurdles 
and *lot* of debugging so really happy someone appreciates it.

I don't imagine many people are interested in actually building one of 
these as its so niche, but if I get some interest I might be talked into 
placing an order with nextpcb/pcbway to get a batch and bring the bare 
boards to CoCoFest. Not looking to make money; would probably be at cost 
at $6-7 per board (unfortunately not as cheap as my usb serial card bare 
boards were as I'm now out of coupon codes). I also have two spare 
Am9511-1DC chips (the version up to 3 Mhz) if anyone is interested in 
those (my cost was $8.25 each).

Oh, and Mark, I saw the test procedure you referenced in the CCS 7811 
manual used PUPI; thats the exact same test I used when I was debugging. 
The first time I saw 02C90FDA come back correctly I was very happy. Very 
fitting to discuss on Pi day. :)

Thanks,

Don

On 3/14/23 11:07, Mark Overholser wrote:
> Don:
> Thanks for this Cool Project and ALL the Background Info..
> I have an AMD 9511 Co-Processor card for my Apple ][ but haven't 
> "delved into" what it takes to interface it with Assembly Language 
> with the 6502.  I also haven't located the Apple Software to Patch the 
> APPLESOFT BASIC , ( also a Micro-Soft BASIC ) to leverage the 
> Co-Processor.
> This is an Applied Analytics uSPEED Math Co-Processor Card with an AMD 
> AM9511A
> http://tech.markoverholser.com/files/HPIM5346.JPG
> which seems very similar to the "Model 7811 Arithmetic Processor" from 
> California Computer Systems , because this card passes the CCS 7811 
> Install Test, found on Page 2-3 of the Manual.
> http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Interface%20Cards/CPU/CCS%207811/Manuals/CCS%207781B%20Arithmetic%20Processor%20-%20Owner%27s%20Manual.pdf 
>
> With your research, I can probably Make my own APPLESOFT Patches and 
> leverage the AMD 9511 on the Apple ][ as well as make your card and 
> leverage the AMD 9511 on the CoCo..
> MarkO