[Color Computer] [Coco] high density floppy controller mods

[Mike Pepe]

Joel Ewy wrote:

> 
> My 3029 has the MB8877_ <-No 'A'.  Anybody have any idea if this is
> significant, speed-wise?

Yes, I think the non-A version is slower. Not sure if that's significant 
in this instance.

> I'm very tempted now to get out my Disto schematics and bash them
> together with yours to get a high-density controller with a sector
> buffer for no-halt operation, and a 28-pin EPROM socket or two.  If I
> did attempt to build such a thing, I would start over on a new PC board,
> just using the MB8877 chip and the data separator from the original
> controller.  I've got a homebrew CNC PCB drill press that's just waiting
> to punch holes in some copper-clad...

Actually I'm trying to do the same thing, kind of a hybrid 
Disto-compatible HD floppy controller. The nice thing about such a 
design is that the I/O would not be dependent on the CoCo speed.

Tony's schematics have some intentionally introduced logic errors, so if 
you follow them precisely you'll have something that doesn't work. 
However they are a good guide to see what the thing does.


-Mike