HP 7942 Service Manual page 90

P7
JO
31
32
33
34
35
36
37
38
39
3A
3B
JC
3D
olE
3F'
P3
Service Information
7942 and 7946
I I
OA OB OC 00 OE OF' 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F' 20 21 22 23 2425 26 27 28 29
Z Z Z Z Z
Z Z Z Z Z
E Z
Z
S
S
S
S
E
()E = DATA ERROR BYTE
E~ - DISC CONTROLl£R IC ERROR REGISTER
FC - FAULT CODE UST
S E
Z
Z
Z
S
Z
Z
E S F'e F'C
N
E S Fe
DE DE
N S S
N
S S
S S S
S S S
E E E
F'e Fe
S S
S S
S S
Fe Fe
Fe Fe Fe
Fe FC
N
=
NUMBER OF SEEKS
S - DISC CONTROLLER IC STATUS REGISTER
Z - ALL ZERO'S
Z
DE DE
S
S
S
S
E
Fe Fe
S S
S S
S S
Fe EC
Fe Fe
Fe
tOF3
ALE=F'5.JEF18A
Figure 4 - 3. P 8 Signal Source (Sheet 1 of 3)
4-21