Epson PX-8 Technical Manual page 282

REV.-A
Pin No.
Signal Name In/Out Function
15 P71
Out Data write - prevents FF latches in gate array
at power off.
16 P72
Out Data write - D-RAM refresh control signal
during power off.
17 P73 Out Data CAS
18
RS In Reset signal input
19 CL 1 In
Clock signal input
20 VC
In +5V (Battery voltage: VB) terminal
22 CL2 In Clock signal input
23 POO/INTO In POWER switch
- -
24 SCK Out Shift clock signal output - used for A-D con-
version data/main CPU command read.
25 SO Out Serial data output
26
SI In Serial data output
27 P60 In RESET switch
28
P61 In Charge start detection
29 P62 In Analog interface trigger input
30 P63
In Test point
31 P50 In Key return 4
32 P51 In
Key return 5
33 P52 In Key return 6
34
P53 In Key return 7
35 P40 Out Reset signal - initializes main CPU and slave
CPU, etc. via GAH40.
36 P41 Out Charge mode control- normal/trickle charge.
37
P42 Out Auxiliary battery backup enable/disable con-
trol.
38
P43
Out Interrupt to main CPU
39 G In Ground terminal
40 X1
In External clock signal input - 1 kHz
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