HP-48GX DIY infrared to serial converter

[pito]

Thanks for the hints!
Why I want the infra - my 48gx is in perfect condition and I do not want to risk a damage while messing with hw serial (as the calculator is almost not repairable).. And yes, I made myself the hw serial long time back, it worked fine.

PS: here is an another receiver only for a printer. Also there is a discussion on the IR receiver chip as well..