So I got the programmer I ordered finally, and I've been having trouble getting it to show any signs of working correctly. It's supposed to be a Willem EPROM programmer. "Dual Power USB" or some such crap.
Anyway, I have many EPROMs that are blank and a chip that is known to have been programmed. However no matter what I do, it reads everything as 00s. I have no idea what I could be doing wrong. It passed the hardware test in that it knows it is present. I set the dip switches up as it showed on screen. But still it says nothing but zeroes. And attempts to write fail.
The chip types I have are a programmed 27c801, 12 erased 27c010s and 4 27c020s. Also I have a 27C256. It is my understanding if the ROM were blank it would be all FFs. I've tried using external power and it did not seem to help (9vdc). Any ideas?
Anyway, I have many EPROMs that are blank and a chip that is known to have been programmed. However no matter what I do, it reads everything as 00s. I have no idea what I could be doing wrong. It passed the hardware test in that it knows it is present. I set the dip switches up as it showed on screen. But still it says nothing but zeroes. And attempts to write fail.
The chip types I have are a programmed 27c801, 12 erased 27c010s and 4 27c020s. Also I have a 27C256. It is my understanding if the ROM were blank it would be all FFs. I've tried using external power and it did not seem to help (9vdc). Any ideas?