Introduction & HP-50g printing issue

[neonjohn]

Hello gang, I thought I'd introduce myself. I'm John DeArmond, a retired nuclear engineer, now occupied most of the time as the Chief Engineer at fluxeon.com, a company that manufactures induction heaters. Oh, and I'm an HP calculator nut. I have my original 45 and 97, a fairly complete 41 set, an original model 48 that never got used and now an HP-50g.

My current obsession is making the 50g and my HP IR printer actually work together. I've done quite a bit of work in that area and posted it over in comp.sys.hp48. Joe Horn suggested that I might also want to come over here and start posting about my work.

Simply put, I AM going to make my 50g print from several feet away. I've spent a great deal of time analyzing the current setup, the IrDA transceiver module, the circuitry, the module programming (the calc programs the module to low power mode upon power up.) I'll post the details of that work in another post if there is interest.

I have removed a cathode resistor from the LED that limited power and I've defeated the power-on low power programming. The result is that I can print from couple of inches of separation instead of with the lenses in contact plus a hope and a prayer.

Clearly not enough, I'm looking at one of two basic approaches. 1) making a tiny daughterboard to hold and translate the pin-outs of a higher power IrDA module and 2) dispense wtih the IrDA module and design a board to use a high powered 5mm IR LED, probably losing the IR receive function in the process. The receive function is useless since holding two calculators in contact with each other will not result in communications ( have 2 50gs).

I think that option 2) is going to be the ultimate solution. Of the IrDA modules stocked by Digikey and Mouser, the brightest one is only a few db more than what I have now. That leaves conventional IR emitters, of which there are some very bright ones stocked by both distributors.

I have several questionss.

* Is the IR receive functionality important to you?

* is there much interest with 50g owners regarding functioning printing?

* If there is interest, is there enough that I should design the solution to be reproducable by others or should I simply do a one-off hack for myself.

* Is there sufficient interest in printing that you'd either buy a kit to modify your calculator with or you'd send your calculator to me for modification?

Finally, any suggestions, tips, pointers to previous work, etc., would be most welcome.

Thanks
John