Andy Warren, >The 16C73's code-protection works a little differently; there are two >code-protect bits, and you can selectively protect the entire code >space, the upper 3/4 of the code space, the upper half of the code >space, or none of the code space. Unprotected areas can be read and >programmed. thanks for straightening that out, I've found the relevent paragraph now... so even OTP devices can have their unprotected ROM reprogrammed? I assume it's just the one extra time. - Andy.