we are trying to program this chip the origional chip got erased by error so we had 3 other units with the chip copied the chip. but when we try to program it bace we get an error, i have tried programing it to intel & AMD chips same error. if i start at address 100 to the end it then programs but if i try to program the whole thing i get an error
Can you read the chip? Is the chip been erased? Do a blank check to confirm this. As I know all 28F256 chips are compatible, so, you can use other brand 28F256 type to try. IF it is working then the software may need to update.