DEC Dual RS-232 connector

#Computer#Serial Interfaces#DEC

Found on the DEC Multia and DEC UDB (Universal Desktop Box). It contains two Serial ports on one connector. The 1st Port is located on the normal pins, and the 2nd port is located on some “spare” pins.

25 pin D-SUB MALE connector pin-out & layout

25 pin D-SUB MALE connector  at the computer

PinPortNameDirDescription
1 n/c Not connected
21TXD-->Transmit Data
31RXD<--Receive Data
41RTS-->Ready To Send
51CTS<--Clear To Send
61DSR<--Data Set Ready
71+2GND-Ground
81DCD<--Data Carrier Detect
9 n/c Not connected
10 n/c Not connected
112DTR-->Data Terminal Ready
122DCD<--Data Carrier Detect
132CTS<--Clear To Send
142TXD-->Transmit Data
15 n/c Not connected
162RXD<--Receive Data
17 n/c Not connected
18 n/c Not connected
192RTS-->Ready To Send
201DTR-->Data Terminal Ready
21 n/c Not connected
221RI<--Ring Indicator
232DSR<--Data Set Ready
24 n/c Not connected
252RI<--Ring Indicator
Note: Direction is DTE (Computer) relative DCE (Modem).

DEC DLV11-J Serial connector

DEC MMJ connector