TL866A repeatable error trying to program EPROMS

[linker3000]

I've had my TL866 for many years and it works fine for various microcontrollers, but I am having problems programming EPROMs. Software/firmware is the latest version.

I have tried with old stock 27256, 27C256, 128 and 512 devices of various brands, and a couple of NOS 27C128s, and the verify error is always at the same locations: 0000, 0100, 0200 etc..

0000 should be F3, got F7
0100 should be 23, got 2F
0200 should be ED, got EF
0300 should be 01, got 0F
0400 should be 3E, got 3F
0500 should be 20, got 27
etc.

This is reproducible. I've changed USB cables, ports, used a powered hub and a different computer

Anyone else/any thoughts?

[TheSteve]

I've programmed 27C256 and 27C512 with mine with no issues - perhaps you have a bad IO line.