[TerraHertz]

This was an amusing read. I'd not heard of using DRAMs as image sensors, but I had discovered that EPROMs sort-of worked as image sensors. Back in the 80s I was writing video poker machine games. 6502 running at 700KHz clock rate, very simple boards using interleaved video/CPU memory access, and all graphics done via 8x8pixel sprites, that were programmed in EPROMs. One day I noticed that bright sunlight on a sprite EPROM (no cover label) produced on-screen garbage. With a bit of experimenting, I found I could get a fairly decent image into the screen. Wrote a program to generate an index mapping into the game screen RAM, so the sprite EPROM was mapping to the screen 'about right', then found that by programming all 1 (or 0, I forget now) into the EPROM then partially erasing it, I could get it quite sensitive to light. I only tried hand holding assorted crappy lenses in front of the EPROM window, and there were all sorts of optical and electrical and geometrical artifacts. But it kind of worked. Pity I have no photographs of those experiments. Didn't consider it anything more than a silly amusement. Especially since I already had a nice B&W PAL video camera.