> 	It is a very simple macro included as an example in the
> gpasm assembler.
>
> movwf1          MACRO   arg             ;diddle regs in RAM bank 1
>      movwf       (arg^0x80)              ;invert MSB
>      endm
>
> I thought this macro would invert the bank select bit and write
> to 0x81

The only thing this macro does is what is in its body:

    movwf       (arg^0x80)

It inverts the 8th bit (assuming the LSB is the 0th) of the supplied addres=
s and writes W to that address. What is the purose? To write to an address =
that is in bank 1 without the assembler complaining (I dunno about gpasm, b=
ut mpasm would complain) about the address not being in bank 0. It does NOT=
 set the bank bits!

If you want it to set the bank bits, just add a line that does so in the bo=
dy of the macro.

(But why use assembler anyway? These days there are free C compilers, and t=
here is Jal, and if that is not enough there is Basic, Pascal, ...)

Wouter van Ooijen

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