If you do not possess the Irda door in the PC, buy it!!! But if you do not have the minimal intention of to buy here as you can autobuild it a connection cable. The scheme electrical presented has been supplied from Mario Di Domenicantonio.

Datasheet Read this text: Voltage Regolator LM78L05 Circuito Integrato Maxim Rs-232.zip

RS-232 PinOUT Pin Name Function 1 DCD Received Line Signal Detector 2 RXD Received Data 3 TXD Transmitted Data 4 DTR Data Terminal Ready 5 GND Signal Ground 6 DSR Data Set Ready 7 RTS Request To Send 8 CTS Clear To Send 9 RI Ring Indicator

S25 PinOUT Pin Name Function in/out 1 GND Ground   2 SELF-SERVICE Recognition/control battery charger in/out 3 LOAD Charging voltage in 4 BATTERY Battery out 5 DATA OUT Data sent out 6 DATA IN Data received in 7 Z_CLK Recognition/control accessories   8 Z_DATA Recognition/control accessories   9 MICG Ground for microphone   10 MIC Microphone input in 11 AUD Loudspeaker out 12 AUDG Ground for external speaker   Notes: The telephone detects the attached battery charger via Pin 2 and controls this via a PCM signal at the same pin. Accessories are detected via Pins 7 and 8 The Headset identifies itself through HIGH/LOW instead of HIGH/HIGH Good Job.