Hi there,
The content of the RAM/Flash EPROM and ROM can easily be read by using the MON08 pin on the chip.
There is one obstacle though, you must know the 8 security bytes.
Many Flash EPROM programmers keep a list of the last security bytes used, and try them one by one.
But as there are 2 ^ 8 * 8 = 1.8 ^19 combinations, it can be quite a tough job to try them all.
As the MON08 accepts data at 9600 baud, and echoes it back, it takes 2 * (1 + 8 + 1)/9600 = 2 ms just to send the security bytes. So it will take 1.8 ^19 * 2 ms = 3.6 ^16 s = 1140 million years to try all combinations.
As the erased Flash EPROM contains 0xff in all the bytes, and then in all the security bytes, this is the combination to try first.
Regards,
Ake