11 Oct
2008
11 Oct
'08
12:11 p.m.
On 11 Oct 2008 at 16:59, Phill Harvey-Smith wrote:
Also depending on your system, it may require a ready
signal on Pin 34,
most 1.44M drives supply disk change on this pin, however the couple of
systems I have worked with that require this signal (Amstrad CPC,
Spectrum +3), wiring the signal permenently to ground will do the trick.
And often cause the system to hang without a diskette in the drive,
unless there's some sort of deadman timer on I/O operations. There
are also a few systems out there that have software to interrupt on
ready-to-not-ready transitions to determine if a disk-changed
condition should be checked for--but you mostly see this on systems
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.
On many of those 34-conductor 5.25-3.5 adapters, the jumper for disk
change switches between pin 34 and nothing. A drive with a pin 34
READY output on a PC that's expecting disk-change instead creates
problems.
Cheers,
Chuck
Note some of the older 1.44s may have jumpers to change the ID, and
enable ready. I have some Teac FD-235F drives that are like this (they
have a bunch of jimpers just to the left of the steper motor),
unfortunatly the HF that you have does not.
Also, anyone know if there if it is possible to
slow the spindle speed
so that 1.44M can be done on machines that only have DD data rate ?
(and if so, any of the above drives capable of being slowed ?) Would
that even work ?
Unfortunatly I believe that the spindle speed in 1.44s is always 300rpm,
even when operating in HD mode, and that is fixed in the drive, I don't
think that's possible (with standard drives at least).
Cheers.
Phill.
--
Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !
"You can twist perceptions, but reality won't budge" -- Rush.