You might want to check the ZSETP_TABLE_SIZE / nTxtbl stuff in core/kbd.c for this camera, I'd guess it should be the same as ixus870
I actually did take a look at that but decided not to change it just yet.
I now have several hours invested in reformatting and commenting the USB remote code. Documentation of how the code is supposed to work does not appear to exist (there is some SDM specific stuff to provide clues but its different code). I even bought a Ricoh CA-1 online to do some testing. Guess what - it doesn't work reliably with my cameras - but if you pound long enough on the button you can eventually get the shutter to fire. And as several sections of that code are actually unreachable, I'm not even sure how much of it actually works. So I'm going to wait until I have it figured out before changing anything related to ZSTEP_TABLE_SIZE and nTxtbl[].
I'd be willing to bet that most of the cameras listed in the first
#ifdef of
core/kbd.c were simply put there to get it to compile and are wrong. Apparently remote zoom via USB is not a much used feature in CHDK (SDM may be different).
I plan to start a new forum thread on this shortly to discuss what the current code does, who is using what and what we want to do with it. So far, the best feedback I've had is from reyalp - "Nuke it from orbit".