If your yellow tubes don't have a plus on one end or minus on the other, they are not electrolytic. Also, if the value is less than 1 mf they are more likely paper dielectric. Paper dielectric deteriorates some over the years, but if nicely sealed up with wax (as the high quality ones were) they hold up way better than electrolytic. Paper caps don't explode, either, as electrolytics can in the power supply near the power amp.
I found Mr Kikennon's thread on his giveaway scanning software for a cheap commercial key scanning PCB,
MIDI Programs Posted I'm thinking of buying some of these for my H to add midi controlled sounds. Hauptwerk as mentioned above, is, I believe, even more expensive than midi-boutique, and runs on a fairly capable PC. The diy'ers in organforum are running more to jorgan for PC's which see.
I've got some Intel 8051 PCB's from the early 80's, but they are not the intel brand MCS-51 board, so I doubt Stratus46's software would help me. Thanks anyway. Not much chance of finding a PROM programmer for those obsolete PROM's, either. Mr. Kikennon's stuff runs on allegedly currently available technology. Several people on organforum warn against implementing matrix keying, as opposed to 1 at a time, and the Conn is definitely a 1 at a time box as now wired. Again, much thanks for the offer.
Lot more knowledge is available on organ forum, firepowerforfreedom, so if you get into this start a thread on the midi section over there. Sorry I didn't see your posts. Midi-boutique is a painless solution, but way above my budget now, and perhaps, yours.