[Coco] CoCoFEST! Challenge: CoCo DMA

Matthew Stock stock at csgeeks.org
Tue Mar 10 16:18:22 EDT 2020

Hi Jim,

Something I worked on a few years ago you might be interested in:
https://github.com/mattstock/cococpld.  It does something similar to what I
think you're working on, in that it has a SRAM attached to a CPLD, and that
memory can be accessed from both the CoCo as a ROM as well as acting like a
SPI memory device for an Arduino or similar.  I was in the process of
expanding functionality to emulate a disk drive.  When CoCo SDC came out, I
kinda lost interest in the project, but the dynamic ROM cartridge bit
worked really well.  I haven't touched it in a long time, but if I moderned
it up I might move from a CPLD to a small FPGA and put in level converters
for the 5v, which would allow a more recent version of Quartus.


On Thu, Mar 5, 2020 at 9:11 PM RETRO Innovations <go4retro at go4retro.com>

> On 3/2/2020 7:30 PM, RETRO Innovations wrote:
> > On 3/2/2020 7:29 PM, RETRO Innovations wrote:
> >>
> http://www.go4retro.com/2020/02/26/direct-memory-access-possibilities-on-the-tandy-color-computer/
> >>
> >>
> > http://www.go4retro.com/2020/02/28/coco-dma-early-efforts/
> >
> > Jim
> >
> http://www.go4retro.com/2020/03/05/coco-dma-fighting-on-the-bus/
> Jim
> --
> RETRO Innovations, Contemporary Gear for Classic Systems
> www.go4retro.com
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