>
>Totally agree, BUT the kicker here is that the register that needed 
>initialising DID NOT EXIST on
>the chip that the code was originally written for.

I hear ya.
They had to have reworked the int vector table though, and they SHOULD have 
walked through the I/O inits and set anything they cared about. Apparently 
they didn't.

I've also seen apps where they didn't completely populate the vector table, 
which I also consider very dangerous. An accidentally enabled int that 
happens, then warps you to hyperspace.  I always populate them, at least 
with RETI's and if I'm feeling paranoid, I put in the code to disable the 
int, so if it is ever enabled, it gets turned back off when/if it 
happens.  Takes codespace though, and sometimes that's a problem.

>As the 4414 to 8515 upgrade 'just worked'

Danger will robinson!

>, the customer didn't involve me at all - the Atmel guy told them it was a 
>drop-in replacement, they tried it and it worked.
>It was only after the second obsolescence that this subtle issue 
>manifested itself, in a
>particularly nasty way, i.e. failures in the field.  It was more by luck 
>than anything else that I spotted the difference and figured out what was 
>happenning.

Would have been more nasty if you didn't know it had been ported, but I 
suspect a sim walkthrough would have shown it up.

Still much less painful than porting PIC apps between families.
:)

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