I can read and verify all my eeproms (27c64,27c256 and 27c512) but by the time I try to write them (yes they are empty and all check out with the blank test) I get an error after the first bit. Sometimes they seem to program and fail at the last bit but the chips are still empty after the "programming".
yes, I've tried all the different setting in my BIOS and on 3 different PCs.
Hi I purchased one of these (PRG 001) April 2005,and have been well pleased with it,it does burn 27xx series as per instructions provided with the kit.
1.Verify the eprom is empty,leaving it in the UV eraser a longer time(i found the erase times differ from even the same manufacture even brand new)if after one time if does not verify empty. 2.Remove the jumper above the ZIF socket and press once the button to the right of the jumper,this sets the voltage to 15v.The 27xx is 12v proram. Now you are ready to program. When finished,replace the jumper(You will see the 15v led go off and the left led go on(the jumper is a safety feature and resets the voltage so as to not damage flash eeprom's) regards G