Posts: 141
Threads: 35
Joined: Jun 2007
Not trivially. PC infrared ports talk IrDA,
an extremely hairy suite of protocols; when you use the infrared port as a serial port, you are really using the IRCOMM protocol of the IrDA protocol suite. The HP48 infrared protocol is extremely simple; two kinds of pulses, one for 0 and one for 1. There have been cicuits published on how to make an IR interface for the HP48, but it's just as simple to make a serial cable (although I imagine that you have your reasons for asking on how to do it over infrared).
Check out www.hpcalc.org; there should be some information on it there.
/ji