EPROM problem

[Guest]

Hello,

we have a problem with programming 27C64 EPROMs from Fairchild. Blank checking and programming is ok, but we get a verify error at address 0000h. The byte is still FFh instead of 02h.
We have a few tubes of these EPROMS. All show the same behavior. A few month ago, these chips worked ok.
What has happened? Any idea?
We use Dataman 48.

Best regards,
Carsten Hoffmann

[Dataman (Neil Parker)]

Dear Sir,

Which revision of the Dataman 48 software are you using? If you are not using the latest revision 4.64 free from our website then please download and install that revision. If that does not resolve the issue then please contact me direct
on [email protected]

Best regards,

Neil