> w_temp  EQU     0x20
> MyVars  EQU     0xA0
>
> MainCode
>          banksel         MyVars          ;set up for bank 1 read
>
> Interrupt happens here                  ;instructions save W into wrong
> bank (MyVars) first off.
> 0x004   movwf   w_temp
>          ...                             ;much other overhead can't
> possibly recover 0xA0 value.
>
>          movf            MyVars,w        ;old MyVars was clobbered.

You either have to reserve the W save area at the same offset in all
banks, or in the global RAM from 70h - 7Fh.  See my interrupt template
module QQQ_INTR.ASPIC at http://www.embedinc.com/pic.

> INT_VECTOR   CODE    0x004        ; interrupt vector location
>              movwf   w_temp       ; save off current W register
> contents
>              movf    STATUS,w     ; move status register into W
> register
>              bcf     STATUS,RP0   ; ensure file register
> bank set to 0

No, it doesn't.  You also need to set RP1 to ensure that.  I do a CLRF
STATUS here to set everything to bank 0 in one instruction.


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