@fbz this soviet-era SRAM chip was selected for its easy-to-remove metal cover so that the die can be exposed to light. it's as old as I am and of unknown provenance, so I was worried about possible mechanical failures.
@fbz this is just a normal SRAM chip in a ceramic package. the UV EPROM typically have quartz windows so that you can expose the die to the eraser light without dust contaminating the inside.
@th so is it EPROM that can be wiped with UV light?