Epson PX-8 Technical Manual page 297

REV.-A
Pin No. Signal Name
In/Out
Function
- -
11
INTO In Sub-CPU 7508 interrupt signal
12 SWBCD
Out Barcode power supply (+5V) switching sig-
nal
13 RXC Out Clock which controls receive character
synchronization (RS-232C).
14
BCD In Bar code read data
15 CSIO In HIGH: Indicates that sub-CPU 7508 can ac-
cess SIOR.
LOW: Indicates that main CPU can read/
write.
16 SI In Serial data input from sub-CPU 7508.
17 SO Out Serial data output to sub-CPU 7508.
- -
18 S-INT Out Interrupt signal to main CPU. Gives an inter-
rupt via GAH40D (Z-INT signal).
19 DB5 In/Out Data bus 5
20 DB3
In/Out Data bus 3
21
N/C
-
Not used.
22 N/C
-
Not used.
23
N/C
-
Not used.
24
N/C
-
Not used.
25
N/C
-
Not used.
26 SWRS
Out
Switching signal for RS-232C power supply
27 INHRS Out Controls output voltage during power satura-
tion time of RS-232C.
28 OFF In Power off. To prevent latch-up by isolating
output in high impedance.
29
G
-
Ground
30 TEST In Test terminal. Normally kept low level.
31
N/C
-
Not used.
32 AUX Out RS-232C transmit/receive line control
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