Whats going wrong - programming error

[Malc C]

I'm at a loss as to whats happening when trying to program one of the new(ish) PIC 18F2550 chips, using a JDM programmer (commercially made olimex unit and home built) when using winpic800 (http://siscobf.webcindario.com/winpic800.htm) software

The PIC is identified, the hardware communicates with the software, but I get an error when programming and or varifying, even when inserting a new PIC and then varifying after an erase.

I've tried several settings but still get the error shown below. Any comments ??

[vintage1]

It looks like you are trying to program memory that doesn't actually exist - so whilst you are trying to put CF3F in when read back its FFFF.

the address is also suspicious - 300000 hex is obviously and address that has just stepped over the memory boundary.

[Malc C]

This is really strange - just to see if it was a software issue I inserted a 12F675 and loaded in a simple "flash the led" program and it loaded and verified OK.

So I re-inserted the 18F2550, loaded the HEX code for it and clicked on the program button - this time the code loaded and verified correctly - I'm totally confused !!!

Anyway, it seems to of resolved itself

[Fluid-Druid]

CF3F appears to be the config register in the first window.
I've had problems with this register depending on what speed the pc is running at
allthough I use different pics,just a thought.
Mike