Some PS/2s
used a spaecial floppy drive with, IIRC, a 40 pin card edge
connecotr which carried both the logic signals and power. The signals
were fairly conventional, though, and I might be able to dig out a pinout
of the connnector if you need it.
I've bootstrapped the machine using the previous DOS 3.3 on the hard
drive,
MODE.COM, and a serial cable so that I can get software on/off
the hard drive, but not having a functional floppy drive makes me
nervous. But there's no rush (it's functional enough) so whenever you
get around to it is fine. And thanks!
Form the PS/2 Hardware Interface TechRef...
1 : -2nd Drive Installed 2 : -High Density Select (To Drive)
3 : Reserverd 4 : Reserved
5 : Ground 6 : Reserved
7 : Signal Ground 8 : -Index (From drive)
9 : Signal Ground 10 : Reserved
11 : Signal Ground 12 : -Drive Select (To Drive)
13 : Ground 14 : Reserved
15 : Signal Ground 16 : -Motor Enable (To Drive)
17 : Signal Ground 18 : -Direction In (To Drive)
19 : Signal Ground 20 : -Step (To Drive)
21 : Signal Ground 22 : -Write Date (To Drive)
23 : Signal Ground 24 : -Write Enable (To Drive)
25 : Singal Ground 26 : -Track 0 (From Drive)
27 : Signal Ground 28 : -Write Protect (From Drive)
29 : Signal Ground 30 : -Read Data (From Drive)
31 : Signal Ground 32 : -Head 1 Select (To Drive)
33 : Signal Ground 34 : -Diskette Change (From Drive)
35 : Ground 36 : Ground
37 : Ground 38 : +5V DC
39 : Ground 40 : +12V DC
The polarising key is between pins 34 and 36
I beleive (the manual doesn't meantion it that '-2nd Drive installed' is
pulled low by the disk drive, probably by that pin being connected to
ground. The system detects that on the second drive connector to see that
a second drive is installed.
IIRC, a '-' at the start of the signal name means an active-low signal.
One thing that strikes me about this pinout is the amazing similarity
between the first 34 pins and the pinout of a normal floppy drive :-)
-tony
