Re: Help with connecting Duodisk to IIgs

[dalloff@freenet.columbus.oh.us (Dave Althoff)]

Jim Wong (jd-wong@cs.uiuc.edu) wrote:

: We didn't have our DuoDisk modified specifically for our GS, but
: we did take it in a few years previous because it had a nasty habit
: of erasing disks.  The technician did a quick hardware modification
: that fixed the problem, and I've always assumed that he clipped the
: same resistors that cause problems for GS's.

There have been TWO hardware mods for the DuoDisk.

The first hardware mod was to clip two capacitors from the analog board. 
Apparently, certain copy protection schemes would cause the DuoDisk to
trash disks.  Not a good thing!  This mod was supposed to solve that problem.

The second hardware mod is related to the IIgs.  Apparently, the DuoDisk
draws too much current to function reliably on the end of a GS
daisy-chain; the fix involves clipping a resistor or two from the board.

There is a tech note about this, which explains both fixes and which
describes which DuoDisks require what fixes.  I'm not sure where I found
them (it's been a year or more...), but I know I found the information out
on the 'Net somewhere.

--Dave Althoff, ][.
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