I just purchased and started using the GQ4x4 programmer. It works great except for a bunch of Atmel 29C020 flash chips I bought on eBay. They were listed as new, but of course they're not.
Some questions:
1) A few of the chips show an "unknown" ID. Should I still be able to work with the chip if it has an unknown ID? Or does the ID determine how the GQ4x4 programs it?
2) I'm unable to erase or write to any of the AT29C020 chips. I assume that's because they're locked (I have a dozen of them; it's unlikely they're all bad). I went to the Lock/Unlock option and clicked the Unprotect button in the All Sectors group (the Protect button was greyed out). The log showed:
Unprotect .... * Unprotect Ended *
What does that mean? If the Unprotect operation succeeded, shouldn't the Protect button then be enabled and the Unprotect button greyed out?
No matter what I tried with Lock/Unlock, I'm still unable to erase or write to any of the chips.
3) How does the speed setting affect writing and erasing? The erase operation is very fast regardless of the speed setting (and the erase still fails). The erasing operation completes, but the chips' contents are unchanged.
4) The AT29C020's data sheet shows the write sequence for locking and unlocking the chip. Is there any way to know what the GQ4x4 is doing when I click the Unprotect button?