9-pin null modem cable
Telephone circuits

9-pin null modem cable

By internum


9-pin to 9-pin female

Nullmodem Cable, 9 to 9 Pin Female D-SUB
Nullmodem Cable, 9 to 9 Pin Female D-SUB

Signal Description:
1 - Carrier Detect
2 - Receive Data
3 - Transmit Data
4 - Data Terminal Ready
5 - System Ground
6 - Data Set Ready
7 - Request to Send
8 - Clear to Send

Pins 6 &1 are wired together to simulate 'on-line' status. This Nullmodem configuration is also for gameply like Westwood's Command & Conquerer "Tiberian Sun".

1347 22 August 2007

See also:

Telephone In-Use Relay Controller
Circuit to close a relay when any phone extension is off-hook.
Telephone Audio Interface
Audio from a telephone line can be obtained using a transformer and capacitor to isolate the line from external equipment.
Telephone Ring Generator Using Switching Supply
The telephone ring generator shown below generates the needed high voltage from a simple switching mode power supply.

Search