IBM 1 Series - Page 114

Teletypewriter adapter
+5V
300 2
+5 V
300 2
+5 V
300 2
+5 V
300 Q
+12V
-12 V~+— |
AYA
A
>
Driver
+12 V
-12V«—_4 |
Driver
+12 V
51kQ
5.1 kQ
620 2
+12 V
§51kQ
5.1 kQ2
Logic ground \ /
Figure 4-3. Output circuits
Serial I/O device
Top-card
connector
pin
AQT SSS closed = data mark
© or TTL minus = data mark
(SSS = solid state switch)
O BO? SSS open = data mark
or TTL plus = data mark
A08
CO- SSS/TTL write control
BO8
O- SSS/TTL read control
B06
O EIA transmitted data
A06
© EIA data terminal ready
A02
CO Current driver, current = mark
BO3
O- Current driver, current = space
(BOS)
Logic ground
Teletypewriter Adapter Feature 4-9