The data sheet for the AMD AM29F010B is severely dicked-up. I found the Atmel version (AT29C010A) and checked their datasheet and found that the erase procedure was different than that stated by AMD (AMD stated the addresses were 555 and 2AA, Atmel says 5555 and 2AAA - slight difference). Tried it Atmel's way and worked fine.
The following paragraph from the Am29F040B Feb.'99 datasheet section entitled "Sector Protection/Unprotection" states. "Sector protection/unprotection must be implemented using programming equipment. The procedure requires a high voltage (Vid) on address pin A9 and the control pins. Details on this method are provided in a supplement, publication number 19957. Contact an AMD representative to obtain a copy of the appropriate document." A faxed copy of this document shows that there is indeed a requirement for a 10V level on the WE pin for the sector unprotect mode for the Am29F040B for certain (current) die revisions. The die revision is not indicated on the device and is only obtainable as a third silicon signature code, the 'Device Unprotect Code'.Information from a programmer manufacturer is that damage may result from not following the correct procedure. This is not mentioned in the supplement, and as the datasheet confirms, 10V on WE would in fact exceed the published maximum ratings.
Thank you AMD. What is the point of publishing a 30 page datasheet without this information?