>
> There are three common ways to do a subtract,Microchip uses
> one of them in the PIC's and 6502 and 6805 use the other two.
> They all treat the carry different. This is the main reason that
> assembly code cannot be easily translated with macros from
> one processor to the next.

It is the use of the carry bit I was refering to not the
instruction syntax (which is I believe unique) The carry
following subtract on the Microchip PIC's is one of the
three results possible in all of the implementations that
I have encountered. It is the same result as a 6502 except
for the subtract 0 case.

The difference is the carry bit shows the results of the
last operation in the process. Take the following examples
with both a and b set to 0

result = a + ~b + 1   Carry=1
  or
result = ~b + 1 + a   Carry=0

Walter Banks