Card Reader Versions 82104A

[klacombe]

I 'm considering sending a card reader to be repaired but am curious about the different versions that were produced. I have a 1D, 1E, and 1F version, each not working but all there. I'd like to at least get one going and wondered which one to go with. I feel pretty fortunate to have obtained a copy of "Extend Your HP-41" and appendix C describes the bugs associated with the card reader. It seems as though some bugs related to card readers have the potential to be a benefit at times. Any thoughts? I plan to get one working now but will explore self-repair for the others in the future. -Kevin