I just purchased a REVELPROG-IS programmer in order to make duplicates of a 93c46a serial eeprom in an old (25 years) synthesiser I am restoring. I did some tests on some new 93c46a devices I bought to act as the original's replacement, and found some odd behaviour.
With a new 93c46a device (a Microchip Technology 93C46A-I/P) I can check contents and erase the device no problem, using the '93..46 (8bit)' device profile. If I make changes to the buffer contents and then try to write the buffer to the device, I see an error saying that verification failed. Once I clear this error, I see a buffer of all 0s. If I read a second time, I see the correct data that I entered. This behaviour appears to be consistent; the first read always produces zeroes, the second read always produces the actual data I've written.
I also notice that each read/write process takes several seconds; a read process takes around 5s for the progress dialog to disappear, while a write process takes around a similar time.
Is this expected behaviour, or should the read process be successful first time round? And should the read/write process be quicker than 5s? The YouTube videos I've seen seem to suggest that read/write should be pretty instantaneous.
REVELPROG-IS programmer, serial W-2340
Windows 10 Home edition, running within VMWare Fusion v8.5.8 on a MacBook Pro running MacOS 10.13.6