B-10 Pin Assignments
EXPANSION PORT PIN ASSIGNMENTS (CONT’D)
Pin
Signal
Pin
Signal
55
Mouse Clock
84
FD – Direction In
56
Mouse Data
85
FD – Boot Select
57
Keyboard Clock
86
FD – Low Density
58
Keyboard Data
87
FD – Write Enable
59
N.C.
88
FD – Step
60
+12 V sys
89
LA23
61
FD – TRACK0
90
LA22
62
+12 V sys
91
LA21
63
+12 V sys
92
LA20
64
+12 V sys
93
LA19
65
+12 V sys
94
LA18
66
+12 V sys
95
LA17
67
CRT – red
96
FD – Write Protect
68
CRT – green
97
FD – Disk Change
69
SA17
98
FD – Read Data
70
SA18
99
FD – Index
71
SA19
100
CRT – Blue
72
MEMCS16
101
CRT – Hsync
73
Refresh
102
SD8
74
PR – Data Strobe
103
SD9
75
PR – ACK
104
SD10
76
PR – Busy
105
SD11
77
PR – PE
106
SD12
78
PR – Select
107
SD13
79
PR – Auto Feed
108
SD14
80
PR – Error
109
SD15
81
PR – Initialize
110
Master
82
PR – Select In
111
Serial – CD
83
FD – Head Select
112
Serial – TXD
