Hacked TIs with "fake memory clear" and other clever tricks were/are pretty common too.
But the most impressive I've seen were some calculators I saw in Shenzhen a few years ago which looked like simple solar-powered 4-function ones, but were actually programmable and had several tens of KB of memory. Trying to use that functionality with a 8-digit 7-segment display, however, was quite challenging.
But the most impressive I've seen were some calculators I saw in Shenzhen a few years ago which looked like simple solar-powered 4-function ones, but were actually programmable and had several tens of KB of memory. Trying to use that functionality with a 8-digit 7-segment display, however, was quite challenging.