TEXAS TI-74 BASICALC & 8K RAM Cartridge teardown

[brouhaha]

(06-02-2024 02:00 PM)dmh Wrote:  The calculator must have a way of detecting a ROM vs RAM module.

I don't know specifically about the TI-74, but in general this is done be the simple expedient of attempting to write to it. It's much less common to have an out-of-band means of distinguishing RAM from ROM, though the HP-71B has such.