This idea doesn't work either since (look below)
Okay, a checksum on a single byte of FF yeilds an FF
I found this to be interesting......
Byte 0 = F3 Sig = FE Byte 1 = 3E Sig = 1EE8 Byte 2 = 00 Sig = 1EE8 Byte 3 = ED Sig = 225A Byte 4 = 47 Sig = 56B6
Byte 12 = ?? Sig =910E Byte 13 = 00 Sig = 20F6
It isn't using the last read byte as the divisor is it?
Kev
"Rom Signature is a four-digit HEXADECIMAL number that is a shorthand representation of the data obtained in an area of ROM memory. The ROM signature is obtained by successively dividing the data in ROM by a binary number (they DON't say what the @!$%#$@% number is! - JR). The resulting signature identifies the data from which it is obtained, and provides a convenient way of" (....blah blah, no other description of the process)."