Pin Assignments
CPU Serial Ports

Sun-4/15/30, SPARC Xterminal 1, SS4, SS10, SS10SX, and SS20 RS-232/RS-423 Serial Ports A & B 25-Pin Female D-Sub
PIN SIGNAL PORT PIN SIGNAL PORT 2 TD A 14 TD B 3 RD A 15 TC A 4 RTS A 16 RD B 5 CTS A 17 RC A 6 DSR A 18 TC B 7 GND A 19 RTS B 8 DCD A 20 DTR A 11 DTR B 24 TCO A 12 DCD B 25 TCO B 13 CTS B Port B is asynchronous only

Sun-4/15/30, SS10, and SS20 Adapter 530-1869 Serial Port A 25-Pin Female D-Sub
PIN SIGNAL PIN SIGNAL 2 TD 8 DCD 3 RD 15 TC 4 RTS 17 RC 5 CTS 20 DTR 6 DSR 24 TCO 7 GND

Sun-4/15/30, SS10, and SS20 Adapter 530-1869 Serial Port B 25-Pin Female D-Sub
PIN SIGNAL PIN SIGNAL 2 TD 8 DCD 3 RD 15 TC 4 RTS 20 DTR 5 CTS 24 TCO 7 GND Port B is asynchronous only.