so i bought 15 eproms off ebay and they were already erased. only 5 i could actually program, the rest i have verified are erased, but they wont program. is this a common problem? i again erased them myself and still the same result. do eproms expire?
Are you sure your programmer can program these EPROMs? Programming algorithms vary from device to device.
If using the Willem, also check the datasheet to see the programming voltages. I know some of them require raising VCC to 5.5V, which the Willem has a jumper for that's not shown in the software. I found that out the annoying way (by doing a bad burn to my only OTP 27C801).
They do expire, but it's kinda doubtful they've been used that much.
thats probably it. i was searching google and that was a big problem. how do i change the voltage? [
quote="Memblers"]If using the Willem, also check the datasheet to see the programming voltages. I know some of them require raising VCC to 5.5V, which the Willem has a jumper for that's not shown in the software. I found that out the annoying way (by doing a bad burn to my only OTP 27C801).
They do expire, but it's kinda doubtful they've been used that much.[/quote]
Do you have a Willem programmer? If so, you might have a sheet that they sent with different jumper settings.
If you have a programmer similar to the one below, the jumpers for voltage should be on the right hand side, and some on the upper right corner. It is hard to see them printed on the PCB, but check that attached sheet of paper or CD they sent with it. If you don't have either, I may be able to scan mine in for you.
Good luck,
NC
It's J8 on my burner. 3 pins for 2 possible jumper positions, it also says 5V on one end, and 5V6 on the other.
ok, so here is the willem programmer i have:
so i should switch the J8 jumper to from the bottom 2 pins to the top 2 pins?
Yeah, towards where it says 5V6 on there (same place as my board). You'd better check your EPROM's datasheet first though to make sure that's even right to do.