HP 7925D Service Manual page 239

Appendix A
7925
Table A-II. HP 7925H Motherboard PCA-A7 Signal Distribution List (Continued)
A1*
DATA PCA
COMMENTS
To Power and Motor Regulator
PCA pin A9J1-14.
J3 J2
A7
MOTHERBOARD PCA
4
J1 XA6P1
A6
R/W
PREAMPLIFIER
PCA
U
XA5P2
AS
TRACK
FOLLOWER PCA
XA5P1 J2 J1
5
R
XA4P2
A4
DRIVE CONTROL PCA
XA4P1
A3
SERVO PCA
XA3P1 XA2P2
v
XA2P1
A2*
MICROPROCESSOR
peA
XA1P2 XA1P1
I I
N at" Clear Offset
Currant Command
DEFINITION
"Not" Clear Attention
"Not" Controller Preset
"Not" CE Pack Installed
CC
SIGNAL
MNEMONIC
CRB Carriage Back
S 13
From Carriage Back Detector.
Also, to Power and Motor
Regulator PCA pin A9J1-28.
CYL
00
01
02
03
04
05
06
Set Cylinder
I nternal Control Bus Bit 0
I nternal Control Bus Bit 1
I ntarnal Control Bus Bit 2
I ntarnal Control Bus Bit 3
I ntarnal Control Bus Bit 4
I ntarnal Control Bus Bit 5
I nternal Control Bus Bit 6
11
11
L
M
to
9
7
K
11
11
L
M
10
9
7
K*
*
Not Usad
DENOTES SIGNAL SOURCE
* WHEN DSU IS INSTALLED, SLOTS A1 AND A2 CONTAIN HEAD
ALIGNMENT PCA AND I/O SECTOR PCA, RESPECTIVELY.
A-66