23 Mar
2010
23 Mar
'10
5:35 p.m.
On 23 Mar 2010 at 12:44, Liam Proven wrote:
Noting the discussion on old media, a slightly
different question.
Please excuse my profound ignorance on matters electronic!
I have read, somewhere, that it is possible to connect HD floppy
drives to elderly kit that is only expecting DD drives, and use them
for just DD operation.
Yes, that should work, but HD drives generally don't provide a READY/
output on pin 34 and some systems require this signal. For example,
my old Amstrad Joyce looks for the READY/ signal on pin 34 of the
interface, which is DISK CHANGED/ on most HD drives. Tying the pin
low generally works for all but those uncommon applications that poll
READY to see if a disk has changed.
As far as select--while it's nice to have a drive with select
jumpers, it's also possible to take an inexpensive drive that's
permanently wired as DS1 and simply swap the DS1 and DS0 lines at the
connector--not exactly the "IBM PC twist", because you want to leave
the motor conrol pins as-is. So the "twist" to get a DS1-only drive
to recognize DS0 would be the 3-wire bundle 12-13-14.
--Chuck