...I had a 2716 EPROM but no UV eraser, so I tried to calculate how long I would need to leave my EPROM on the back porch to achieve full erasure from sunlight. I think it was on the order of days, so it seemed like a feasible alternative, assuming I wrote bug-free code so I wouldn't have to do multiple cycles.
On the truly old-school EPROMs, one of our local ham repeaters had a homebrew controller with an 1802 EPROM, and my programmer couldn't come up with the 48V programming voltage for the 1802. I found a guy with an 1802 programmer who was kind enough to program a new callsign into the chip. I gave him a Z80 single-board computer on behalf of the club to thank him for his work.