PIC problem

     Ladies, Gentlemen:

     I'm somewhet new although I've been lurking here a while.

     I've got a problem I hope someone has some insight into.

     I bought the PICDEM2+ with ICD2 combo.  I was interested in learning
     the PIC assembly language, but now I'm solving a 3 phase power
     problem and bought a couple of pic18f4431 processors and stuck one
     in my PICDEM2+ board and it works fine (complete with downloads
     making the p19f4431 run software originally designed to run on a
     P18f452 -with some minor changes-).  Of course I have to "include"
     p18f4431 instead of p18f452 in a place or two, and I need to specify
     p18f4431 elsewhere instead of p18f452, but otherwise the (really)
     simple code inclusive of interrupts] is unchanged.

     So why does a p18f4431 complain when the hardware has some
     differences ?   Granted one '4431 lives in a nice environment, while
     the other is in an almost sparce environment, so what really is the
     difference?  I have to get a '4431 going in a sparse environment, so
     how sparse can it be before it "comes up"?.

     2Penny
     My two cents worth.

2Penny wrote:

>      I bought the PICDEM2+ with ICD2 combo.  I was interested in learning
>      the PIC assembly language, but now I'm solving a 3 phase power
>      problem and bought a couple of pic18f4431 processors and stuck one
>      in my PICDEM2+ board and it works fine (complete with downloads
>      making the p19f4431 run software originally designed to run on a
>      P18f452 -with some minor changes-).
... 
>      So why does a p18f4431 complain when the hardware has some
>      differences ? 

Hmmm, I've never had a processor complain.  I've had engineers
complain and programs give error messages, and sometimes the
processors don't run, but they don't complain.  What does the
processor complaint look, sound, or feel like?

>      Granted one '4431 lives in a nice environment, while
>      the other is in an almost sparce environment, so what really is the
>      difference?  I have to get a '4431 going in a sparse environment, so
>      how sparse can it be before it "comes up"?.

I haven't looked up that chip, but if it has a built-in oscillator
option, then it can run pretty sparce -- just apply suitable power.

Thad