I have been given some sample of the 16F73 to evaluate as a replacement for
the 16C73B we are currently using.
After updating the firmware in the old PICSTART Plus I have managed to
program the new device and it works OK. However, when I read the new device
I only get blanks (0x00's).

If I erase the chip & read it I get successful blank check and it reads as
0xFFs

The programming phase claims success but a subsequent verify fails. However
the program appears to work OK.

If I change the device type back to a 16C73B both read & verify are OK -
despite the fact I am using a flash device. (I have not tried programming
in this mode & do not intend to)

I have checked & double checked the configuration bits etc. and everything
looks to be fine. (i.e. Code protect is definitely OFF).

Has anyone else had this sort of problem or can suggest a fix?

I repeat  - the program appears to run OK and it reads & verifies OK if the
chip type is changed to 16C73B.
I have not implemented a checksum test on power-up - and don't think it's
possible on these chips as the program memory is not accessible. (Maybe
someone could enlighten me if it is).

Richard P

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