1LM2-0002: HP-41C/CV/CX HalfNut System on a Chip specifications?

[Paul Berger (Canada)]

(12-07-2015 06:56 AM)quantalume Wrote:  

(12-03-2015 12:42 PM)Paul Berger (Canada) Wrote:  Here are some notes I made when working on halfnuts, there is really not much to see in both cases the ROMs are hybrids with the dies wire bonded directly to a substrate and encapsulated in epoxy.

Paul, your document shows keyboard column 0 going to pin 18 of the CPU and column 1 going to pin 19. The examples I've seen have 18 and 19 connected together and to column 0, 20 and 21 connected together and to column 1.

Yes that is the way it looks in your picture, I cannot say with any certainty what I was looking at when I made the notes the pdf was derived from, it was years ago when I was still interested in poking around inside 41s.