[Coco] SAMx4 - CPLD-based SAM replacement

[Ciaran Anscomb]

David Ladd via Coco wrote:
> On Fri, Dec 1, 2023 at 7:43 AM Ciaran Anscomb via Coco <coco at maltedmedia.com>
> wrote:
> >
> > http://www.6809.org.uk/dragon/samx4/
> >
> > Schematic, PCB layout, VHDL source.
> 
> Does it work with the SAM accelerator? Or can it replace the SAM and SAM
> accelerator?

The only fancy thing this design (optionally) does speed-wise is feed
video addresses _if possible_ in fast mode.  So in 32K mode you get noisy
video and (enough) refresh, so long as you're mostly hitting the ROM.
Much less use in 64K mode.

This one also has an oscillator on-board, as I didn't want to bother
figuring out how to interface to a crystal, so...  maybe?  As long as
the accelerator didn't require replacing a crystal?  I don't have one :)

..ciaran