If any kind of LIGHT ( not UV light) just regular shop lighs gets through the Eprom labels or EEPROM labs, This can ruin and damage EPROM and EEPROM chips. I can READ the files on EPROM chips but I can't WRITE files to EPROM chips. I know I can read and write to EEPROM chips, but can I write files to EPROM chips. When using a universal programmer to check EPROM and EEPROM chips do you ever change the univeral programmers software settings about the test voltage, margins , etc. Each Universal programmer has different algorithms for testing the checksum. A Bad EEPROM chip can pass the checksum test on one universal programmer but fail on other universal programmers any reasons why?