Date   : Mon, 19 Apr 2010 17:09:00 -0500
From   : jules.richardson99@... (Jules Richardson)
Subject: Re-using floppies

Tim Fardell wrote:
> Also, the Compaq Deskpro 386/20e (the first IBM PC clone I ever used) 
> didn't use the sensing hole at all and would format any disk to either 
> 1.44M or 720k. The activity LED glowed red for DD and green for HD, 
> and on the first access after inserting a new disk you could see it 
> "hunting" while working out whether it was formatted as HD or DD.
> I think I kept one of those disk drives somewhere. They seem pretty 
> unique.

Yeah, that rings a bell too... the first PC I ever had was a Compaq 286 
luggable, and I seem to remember that behaviour for the floppy drive. I don't 
remember if my luggable had the bi-colour LED, though (although something on 
it did - possibly the LED to say whether it was running on mains or battery)

I vaguely recall one pin on the PC's disk interface that was used for all 
sorts of different things depending on manfacturer - one of which was density 
select (others e.g. changing the spindle speed, ejecting the disk, driving the 
LED independently of the drive status)

cheers

Jules