DEC Dual RS-232

Latest revision as of 12:54, 30 December 2006

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.

Pinout

25 PIN D-SUB MALE at the computer.

Pin	Port	Name	Dir	Description
1		n/c		Not connected
2	1	TXD		Transmit Data
3	1	RXD		Receive Data
4	1	RTS		Ready To Send
5	1	CTS		Clear To Send
6	1	DSR		Data Set Ready
7	1+2	GND	-	Ground
8	1	DCD		Data Carrier Detect
9		n/c		Not connected
10		n/c		Not connected
11	2	DTR		Data Terminal Ready
12	2	DCD		Data Carrier Detect
13	2	CTS		Clear To Send
14	2	TXD		Transmit Data
15		n/c		Not connected
16	2	RXD		Receive Data
17		n/c		Not connected
18		n/c		Not connected
19	2	RTS		Ready To Send
20	1	DTR		Data Terminal Ready
21		n/c		Not connected
22	1	RI		Ring Indicator
23	2	DSR		Data Set Ready
24		n/c		Not connected
25	2	RI		Ring Indicator

Note: Direction is DTE (Computer) relative DCE (Modem).

Contributions

• Joakim Ögren
• Greg A. Woods

Sources

• Tommy's pinout Collection by Tommy Johnson
• Digital UDB Information by Eric Smith