5-1/4' drive on modern PC

Tony Duell ard at p850ug1.demon.co.uk
Fri Dec 10 18:17:50 CST 2004


> 
> 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




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