[Coco] Re: FD-502 controller problem

[Mike Pepe]

Charlie wrote:
> Gene and Phil, Thank you for the replies!
> 
> It is not a cable / drive problem as switching to my Disto SC II everything
> works fine.
> It has to be something specific with the 502 controller.
> 
> Charlie
> 

All the signals that run the drives are in a parallel bus configuration, 
except for the drive select signals. If there were a major issue with 
the controller it should affect all drives the same way.

The only thing that would be worth trying would be to replace all the 
7406 (or 7416) chips on the controller and see if that helps. If not 
maybe the big 373 latch chip has a bad output for drive 0's select line.

-Mike