Aw: [stella] X or Y ?

Subject: Aw: [stella] X or Y ?
From: cybergoth@xxxxxxxx
Date: Thu, 15 Apr 2004 12:32:01 +0200 (CEST)
Hi there!

> I had a lot of code like this in Master Mind deluxe
>     lda r1peg1,y
>     sta Dpeg1,y

> I changed it all to this and saved a lot of rom
>     lda r1peg1,x
>     sta Dpeg1,x

> Why? 
> I'v read through the 6502 documentation and can't see any rason why.

There's no "absolute zeropage" adressing mode to some instructions using Y, so the code rendered in those cases will force an absolute 16-Bit adressing padded with "00" for the HI-Byte and so wasting an extra byte.


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