19 May
2013
19 May
'13
2:01 p.m.
On Sat, May 18, 2013 at 4:48 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Alas I can't help you there. The only Apple 3.5" drive I've worked on is
the one in my Mac+. It's 800K (of course), and seems to be closely
related to a stnadard Sony half-height drive, the drive that HP used in
the 9114B, the 9153, the late version of the 9123, etc. It'c close enough
to that drive that I actyualyl receomend using old Apple drives as a
source of spares for fixing the HP machiens (nothing agains Apple, but
their drives are a lot easier to fidn than the HP ones).
I would be interested ot know what the differences in Apple drives are,
too. I wonder if it's basically the same drive with modifications to the
digital ASIC, or a totaly different unit.
> Does anyone know technical reasons why the
M0131 is different from the
> M0130 besides the different mech?
OK... modification to the question... does anyone know the specific
technical differences between versions of 800K Mac drives? It apparently
does matter.
http://68kmac.com/Mac128/Mac_128_Update/Entries/2007/9/1_Formatting_800K_MF…
The 800K drives are variable speed, but they set their own speed.
IIRC, the 800K drive sets the spindle speed
autmattically depending on which cylinder tis's on, the 400K drive takes
a PWM speed control signal from the Mac mainboard.
I do remember that difference now that you mention it. The 400K
drives almost sang as they flew from track to track. There are some oddiites in the floppy cabling, to
the extnt that the
internal drive ribbon cables have 1 or 2 wires missign (solid plastic).
I think that a pin that's a power line (-5V?) on the logic board is
'remote eject' at the drive. But that couldn't be fixed with software, so
that can't be it.
Found a reference... Pins "9 (-12v)" and "20 (speed)" for internal
cabling
(obviously there's no pin 20 on a 19 pin external connector).