I am pretty sure it is wired correctly because I have erased several eeproms successfully, and the eeproms that do work I have erased several times successfully.
I am operating within the voltage tolerances, and have even successfully erased at 12v. I am aware of the 100us CE pulse but it does not specifically state a maximum time for VPP or A9. No issues reprogramming the chips, but only the ones that survived erasing made it to reprogram. and they have repeatedly worked as I was expecting. but it is total hit and miss, mostly miss. I feel it has something to do with that A9 voltage. I wish I knew how it worked, I added a current limit resistor to A9, didn't help, though it made the failures less catastrophic.
I can setup some timing for the erase, but I am skeptical about there being a difference....... and I don't think a denounce would help, because so what if it erases multiple times, but I can test it.
3 of the chips work reliably with my setup.... so far anyway, maybe there just tough, but I would expect them all to be identical
I will have to wait till new chips arrive to test because the chips that work, always work and the chip that don't, don't respond to anything so I have no way to differentiate the test
So I got some time to brainstorm till the new ones show up, so lay it on me!