Electrical Characteristics - IBM 3704 Reference Manual

Electrical Characteristics
+Receive Data. The modem generates signals on this circuit in response to data
signals received from the communication channel. The IBM 3704 and 3705
receive the data as differential voltage level signals.
+Receive Clock. The modem generates differential voltage level signals on this
circuit to be used by the modem.
-Receive Clock. The modem generates differential voltage level signals on this
circuit to be used by the IBM 3704 and 3705.
-Transmit Clock. The modem generates differential voltage levels on this circuit
to be used by the IBM 3704 and 3705.
The electrical characteristics meet the requirements of CCITT Recommendation
V.35, Appendix 4.
Communication Interfaces! 21