Apparently I managed to kill a couple of 27SF512's today. Dug into my box of tuning stuff, and realized I had a few of the 29C256 chips. Hooked up the Autoprom (APU1) and TP5, to upload the '747 and '165 bins to the 256. Both fail at erasing the chip. Reading the chip shows "success", although I have no idea what they were originally used on.

The addressing appears to be correct, as TP5 has the 256 already listed as an option.

I'm able to program the 512's with no issue. Everything seems to indicate the 256's should work with what I have, but I'm having no luck. Probably a setting I'm missing, but again, since TP already has the 256 listed (as it does for the 512, among others), not sure what setting I could be screwing up.

It's not a huge deal, I've got a couple 512's left, but with them not being made anymore (I know you can still get them, but $5/each), I should probably use the stuff I already have.

Any ideas?

Thanks!