17 Apr
2018
17 Apr
'18
11:06 a.m.
Lastly, I wonder if there might be some kind of
checksum check to prevent tampering. Is there a common way this is handled in 8085 world?
Or is it entirely programmer dependent?
One approach that <may> be doable for you is if you have a good ROM with a known
checksum, make your changes then calculate the difference between the new and the original
checksum and make another change somewhere innocuous to bring the checksum back to the
original value. "Innocuous" may be the trick - perhaps some text string you
don't care about, copyright notice etc. or maybe there is an empty area in the EPROM
you could stick a byte.
Richard Sheppard