Re: Aw: [stella] BCD to pointer.

Subject: Re: Aw: [stella] BCD to pointer.
From: "Lee Fastenau" <stella@xxxxxxxxxxxxxxx>
Date: Thu, 13 May 2004 12:23:18 -0700
>Now my problem is multiplying by 5 (the height of my fonts)
>This is how I handle the low nybble 
>	and #$0F	
>	sta temp
>	asl		
>	asl		
>	adc 	temp
>Is there an easy way to do this to the top nybble?
>at the moment I'm lsr'ing 4 times then applying the same method as above.

The second round could be...

; Think of left nibble as val*16
; So divide by 4 to get val*4
; Store that, then divide by 4 again to get val
; Add to stored value to get (val*4)+val = val*5

       and #$F0   ; This is necessary
       sta temp
       adc temp

I think the logic is sound.


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