I take this as an indication that I'm not the only one confused by the
result of the carry bit following subtraction - I always get it wrong - (but
thought I was just not suited to the mental gymnastics involved.)

Richard

> -----Original Message-----
> From: Tony Nixon [mailto:Tony.Nixon@ENG.MONASH.EDU.AU]
> Sent: Tuesday, September 28, 1999 11:24 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Snippets
>
>
> Hi all,
>
> In light of all the discussion recently this may be off topic now ;-)
>
>
> Just a few code snippets I discovered in the last two weeks while
> writing some new software.
>
> if RAMx > Y
>
> movf RAMx,w
> addlw 255 - Y           ; eg if RAMx > 5 ... addlw d'250'
> btfsc status,carry
> goto True
>
> if RAMx < Y
>
> movf RAMx,w
> addlw 255 - Y + 1       ; eg if RAMx < 5 ... addlw d'251'
> btfss status,carry
> goto True
>
> if RAMx >= Y
>
> movf RAMx,w
> addlw 255 - Y + 1       ; eg if RAMx >= 5 ... addlw d'251'
> btfsc status,carry
> goto True
>
> if RAMx <= Y
>
> movf RAMx,w
> addlw 255 - Y           ; eg if RAMx <= 5 ... addlw d'250'
> btfss status,carry
> goto True
>
>
> --
> Best regards
>
> Tony
>
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