[Coco] Re: Digging, Digging...

[Torsten Dittel]

> 1) WD 1773 controllers are 28-pin, not 40. Ungh, I did warn y'all that my
> memory sucked. Not sure if a 2793 can be shoehorn-crosswired into a 1773
> socket or not now... :-/

Actually, if someone would make a new design, it's not important if the
controller chip is "socket" compatible (could be PLCC). It should be
software compatible because most of the advanced non-OS9 software I
disassembled 20 years ago is addressing the chip directly (not just
using the documented BASIC calls).

It's not a good idea to design something for a hard-to-find part.
However, if there are stocks about 200 pieces this would be enough for
the CoCo community.

Help my poor brain: What's the difference between the 1773 and the 1772?
The ATARI ST was using the 1772 and I think it was software compatible.
Later ATARI produced a compatible "homebrew" chip in the STE called AJAX
which was made to run at 16MHz instead of just 8MHz and was able to read
HD floppies. There were several hardware mods out to make a "classic" ST
read HD disks with this chip. You had to modify "modern" HD 3.5" drives
because they didn't deliver the DD/HD detection signal to the controller
and were fixed to drive 1. AFAIR if you had a drive modified you
couldn't attach more modified drives to the same (shugart) line.

Torsten