HP9154 hard disk drive pinout

[Tony Duell]

I had been looking for this info for over 10 years, and I finally found 
it this morning while looking around hpmuseum.net for the manuals on the 
9817. I looked at the service manuals for the 9153/9154, and found what 
is probably the only useful bit of info in those manuals (I really don't 
intend to use a torque wrench to tighten the top cover screws....)

The HP9154 (certainly the later versions) use an HP hard disk drive with 
a single 40 pin power and data connector. It's a strange HP interface, 
with raw data and an 8 bit control bus.  And from what I remember, one 
end goes to an ASIC on the 9154 cotnroller board, the other to an ASIC in 
the drive, so it's hard to work out what all the signals are...

Anyway, from that manual, here's the pinout of the cable. Please save 
this soemwhere, if you need it, you _really_ need it....

1 Rd Data
2 Gnd
3 Wr Data
4 Gnd
5 Wr Gate
6 Gnd
7 4MHz Clk
8 Gnd
9 Rd A-D converter
10 Gnd
11 +5V
12 Gnd
13 +5V
14 Gnd
15 +12V (Motor)
16 Gnd (Motor)
17 +12V (Motor)
18 Gnd (Motor)
19 Dr Sel 0
20 Dr Sel 1
21 Dr Sel 2
22 Dr Sel 3
23 Wr D-A Converter
24 NA/B
25 Sector Pulse
26 Index Pulse
27 Wr NIC Chip
28 Reset
29 +12V (Motor)
30 +12V (Motor)
31 Fault
32 +12V
33 Data Bus 7
34 Data Bus 0
35 Data Bus 6
36 Data Bus 1
37 Data Bus 5
38 Data Bus 2
39 Data Bus 4
40 Data Bus 3


-tony