10 Dec
2004
10 Dec
'04
10:17 a.m.
There was an attempt to "simplify" connection of multiple floppy drives
(meaning TWO) at one time by adding a "twist" to the cable-- some
conductors in the ribbon are cut out and reversed, which is a sort of
"cable select" for floppy drives.
I seem to recall in this case that one would jumper both drives as drive A
in such a case, or as DS0.
I tought it was actually DS1.
Stupid idea. Use a straight thru floppy cable and jumper one for DS0 and
one for DS1. We get it.
The 'IBM twist' also gave you sparate motor-on lines for the 2 drives,
and the original controllers (XT and AT) certainly controlled them
separately. You can't normally get away with an untwisted cable, no
matter how you jumper the drives.
-tony