The 2 DIO model 288's have had firmware changes (from rev 2.? to rev 5.1).
Evidently they made lots of little changes. The main change is the ability
to use a faster programming algorithm on some of the TI Eproms. The next most
significant change is the ability to program 4Mbit Eproms.

Among the little changes was the addition of another byte of checksum. I
changed the DIO programs on the VAX to both verify using a 24 bit checksum and
also to report the 24 bit checksum (note that the lower 16 bits continue to
represent the old checksum values).

ds