Nonpareil status

[brouhaha]

(10-15-2022 06:11 PM)Thomas Okken Wrote:  The HP-25 does this too. I don't know if all the keystroke-programmable HPs work this way, maybe not the 65 and 55?

Yes, but only the 19C ant Topcat models use the PICK chip to scan the keyboard instead of the scanner in the main processor, and of those, only the 19C has the special arrangement to hook one (electrical) row of keys to both chips. In particular, the 97 doesn't have it, so the 97 doesn't have the SST shows key code feature. (I'd best double-check that, but I'm fairly certain.)

The 97 was the first Topcat model I reverse-engineered, and the most challenging since there was very little information on how the PICK worked, and none on the CRC. The CRC reverse engineering was a joint effort between the late Jacques Laporte and myself.