Yes, those are not the drives you want.
None of those exceptions.
I was merely listing sone of the weird ones to avoid (or use for weird
IF I remember correctly (unrefreshed dynamic wet-ware RAM), 34 pins of the
40 pins of the PS/2 drive were the same, and the other 6 pins had the
power. I think that you could simply take a 40 pin cable, connected to
the drive, and split off those 6 pins, and crimp a 34 pin connector on the
remainder for the FDC end. Or, the other way around - a friend had
generic drives in his PS/2. But, I have no idea where my notes went to,
for the pinout of which of the 6 were which, and/or disk/change VS Ready,
how they did the drive select, and possibly a few other minor weirdnesses.
Pinout for PS/2 should be readily available.
generic drives are still readily available and cheaper, so leave the PS/2
drive to the people with PS/2s.
On Thu, 30 Mar 2023, Chuck Guzis via cctalk wrote:
On 3/30/23 10:48, Fred Cisin via cctalk wrote:
The drives in many IBM PS/2 machines don't
seem to have a media sensor,
so they can't tell the difference between "720K" and "1.4M"
"720K" is about 600 Oersted, and "1.4M" is about 750 Oersted, so
are close enough that sometimes one can get away with using the wrong one.
Those PS/2 drives often have peculiar IBM-specific interfaces. For
example, some are 40 pin instead of 34. Or power is shared on the same
cable as signals, etc.
You're not likely to consider them.
There once existed single sided drives. Such as
the original Shugart
SA300 They were used in early Gavilans, but were replaceable with double
sided, especially the SA350, which could use the Gavilan's custom SA300
Epson Geneva PX8 was 40 cylinders, intead of 80, with 67.5tpi, instead
of the usual 135tpi.>
The original Sony FULL height drives were at 600RPM, and had a different
The Tandy Portable Disk Drive, for the model 100, was weird and a half.
But none of those are high-density drives.
I'll add one of the issues may be drive-select setting for non-PC
devices. It's easy enough to get around, however.