Fast Eproms CY7C291 Data?

On 2/24/2012 1:23 PM, Tony Duell wrote: A lot of the Eprom manufacturers had deals with various programmer manufacturers. They warranted that their eproms would program with those manufacturers, or be replaced. There was the desire not to have any one attempt programming their parts as they really could not tell when a bad version of a programmer destroyed their proms. We had a 2732 programmer which worked for a while, but then seemed to start being flaky. I looked at the waveforms of a blank eprom (and never programmed by our programmer) in a circuit, and saw nice clean waveforms for the accesses. After being programmed, and erased the waveforms stopped reaching the 0 level reliably. If I looked at ones that were programmed with other programmers no problem either. At one time the parts were successfully programmed with what we did, which was out of a databook, but then w/o any notice I ever found it stopped working. We didn't have to do that many more parts, and switched to having them done on a Data I/O at our vendor from then on, then later bought a Chinese rig with the ISA card, etc and it worked as well as I could see. Anyway as long as they had the warranty, I suspect they had the problem of who they let do the programming. Jim