Software Data Protection disabler?

[Adamer64]

Hello!

Would it be possible for someone to implement Software Data Protection disabler (or enabler for that matter) to this software? Maybe just as a serial command? I've got single AT28C256 chip that I tried to work with, but after reading it, I just got all 0s and writing stops at the first address pair without any messages or LED blinks after that. Reading again returns 0s (obviously), the same hang happens when I try to clear it.

I'm not too bright when it comes to this low level-implementations, and I can't test it anyway until I get another chip, because I suspect this one is dead anyway.

For reference, second to last page has the requirements: http://www.atmel.com/Images/DOC0543.PDF

Thanks anybody in advance!