[mythtv-users] USB keyboard control of digital cable box

[MythTV User]

send PS2 Clock and Data.  The protocol is explained here:
http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/PS2/ps2.htm

You can use the web page you found for what the data has to look like.

I don't see a problem using perl to bit bang the parallel port.

P.S.

Here is something else I found that you could use:
http://www.usbdeveloper.com/EvalKit/kits.htm#HID%20Compliant%20HID%
20Keyboard%20Kit%20using%20PDIUSBD12

It's a USB keyboard development kit and already has a parallel port 
interface.