Psion TTL serial port pin out table

This table presents an engineer's quick reference to the pin-out of the 9 way 'D' connector used as a serial port at TTL levels on Psion Workabouts.

D-Sub 9 Socket
Viewed looking in to recepticles of socket

 

Pin

Mnemonic

 Signal

Direction

1

 

 No connection

 

2

RD

 Receive Data

DTE <= DCE

3

TD

 Transmit Data

DTE => DCE

4

Vcc

 5V supply for external devices

 

5

Gnd

 Signal Ground

-

6

DSR

 Data Set Ready

DTE <= DCE

7

RTS

 Request To Send

DTE => DCE

8

CTS

 Clear To Send

DTE <= DCE

9

 

 No connection