3.5" floppy drive question(s)

[Tony Duell]

[Disk Change]

> with 8" drives with line-powered spindle motors.  We just polled the 
> write-protect sensor on old 5.25" drives to do the same thing.

The HP9836 system that I've been working on has a pair of 5.25" drives 
which are effectively permanently enabled (the 'MX' jumper is fitted) and 
thus have spearate cables back to the contoller board. The write-protect 
lines trigger flip-flops for a disk change function (as well, of course, 
as being used for the write protect function) while the index lines also 
trigger retriggerable monostables for a ready function (if index pulses 
are happening sufficiently often, there must be a disk in the drive, it 
must be turning). 

-tony