Date   : Thu, 16 Mar 2006 01:16:42 +0100
From   : John Kortink <kortink@...>
Subject: Re: Web site: Mainly Master 512

On Thu, 16 Mar 2006 00:56:12 +0100, I wrote:

>With reference to earlier emails, it's funny to see how
>Acorn manages to save one more routine byte (with a TYA)
>by using :
>
>CLC
>LDY #255
>TYA
>.loop
>ADC addr-1,Y
>DEY
>BNE loop
>
>for both sectors.
>
>Why starting with 255 ends up with the same result as starting
>with 0 (/except/ when all but the last sector byte added in is
>zero !)

Of course, an initial SEC instead of CLC would have
solved this apparent Acorn bug altogether.


John Kortink

-- 

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