Apple III Serial Port Cable Printer Connector
Frame Ground ............(FG)...... 1 <-----> 1.....(FG)
Transmit Data (Tx) ..... 2 <-----> 3.....(Rx)
Receive Data (Rx) ..... 3
Request to send (RTS) .... 4
Clear To Send (CTS) .... 5
Data Set Ready (DSR) .... 6 <-----> 11
Signal Ground ...........(SG)...... 7 <-----> 7.....(SG)
Data Carrier Detect (DCD) .... 8
Secondary Clear To Send (SCTS) ... 19
Data Terminal Ready (DTR) .... 20
NOTE: Printer dip switches need to be set as shown;
FRONT 1 - OPEN BACK 1 - CLOSED
2 - OPEN 2 - CLOSED
3 - OPEN 3 - OPEN
4 - OPEN 4 - CLOSED
5 - CLOSED 5 - OPEN
6 - OPEN 6 - CLOSED
7 - OPEN
8 - CLOSED
NOTE: Jumper blocks should be in position A.