Interfacing with the Parallel port


Thread Starter



I am trying to use the parallel port to generate control lines to set up an external device. The external device requires 3 control lines that are TTL level terminatered int 93 ohms. Since I need to drive TTL levels into 93 ohms (parallel port needs to source/sink about 30ma), I was thinking of tying 2 data signals (D0 & D1, D 2 & D3,..) together to share the current load.

The 3 control lines are described below as well as a readback signal to verify the proper data was sent.

• GATE (write)= remains high for the 20 bits data stream.
• DATA (write)= 20 bit serial stream, 5 bits for address, 15 bits for data.
• CLOCK (write)= can be continuous or gated, with max freq = 16 kHz

• READY (read) = goes from a high state to a low state after the first 5 bits, then back to the high state after the 20th bit, planned on using a status bit for this.

Does any one know if I can do this and how?

If you can email me I can send the signal timing diagram in a WORD document.

Thank you,

Paul Taylor
[email protected]