TANDY 1000RLX (250-1452/53) Pinouts Faxback Doc. # 1325 GND = Ground NC = Not Connected * = Active Low Signal Printer - 25 pin (D-Sub): Keyboard & P/S 2-Style RS-232C Serial Port: Mouse Connectors: 1 Strobe 18 GND Pin Function: + Data 0 19 GND Pin Function 3 Data 1 20 GND 1 Carrier Detect 4 Data 2 21 GND 1 Data 2 Receive Data 5 Data 3 22 GND 2 Reserved 3 Transmit Data 6 Data 4 23 GND 3 Ground 4 Data Terminal Ready 7 Data 5 24 GND 4 +5 Vdc 5 Signal Ground 8 Data 6 25 GND 5 Clock 6 Data Set Ready 9 Data 7 6 Reserved 7 Request to Send 10 Acknowledge 8 Clear to Send 11 Busy 9 Ring Indicator 12 Paper End 13 Select 14 Auto Feed Video Port Connector: 15 Error 16 Initialize Pin Function 17 Select In 1 Red Left Joystick: 2 Green 3 Blue 1 Position 1 2 Position 2 4 No Connection 3 GND 4 Open 5 Ground 5 Power 6 Ground 6 Ground 7 Switch 1 8 Switch 2 7 Ground 8 Ground Right Joystick: 9 No Connection 10 Ground 1 Position 3 2 Position 4 11 Ground 3 Ground 4 Open 12 Ground 5 Power 6 Ground 13 Horizontal Sync 7 Switch 3 8 Switch 4 14 Vertical Sync 15 No Connection