Re: [stella] Very BASIC ASM Info needed...

Subject: Re: [stella] Very BASIC ASM Info needed...
From: Russ Perry Jr <slapdash@xxxxxxxxxxxx>
Date: Thu, 8 Mar 2001 00:56:24 -0600
At 5:14 PM +1100 3/8/01, Andrew Davie wrote:
>That's a pretty neat trick, Russ....   you can drop the clc and replace the
>first rol by an asl (saving a byte, and 2 cycles)

OOooo, I like that...

>    lda FrameCounter
>    asl
>    rol
>    rol
>    sta FrameCounter
>I think, though, that we should count the extra cycles to trim off the low
>bits and transfer to an index register

Damn!  I knew I forgot something...  At first I thought I could do it
with just two ROLs, but then you have to preserve the carry, which
doesn't cut it.

>- the table lookup is a clear winner

Yeah, appears to be.  I can't think of anything smaller at the moment.

>when this is taken into account.  But still, your idea... at just 7 bytes...
>very impressive!

But you're doing that AND a lot to mask the high 6 bits, so...
||  Russ Perry Jr   2175 S Tonne Dr #114   Arlington Hts IL 60005  ||
||  847-952-9729    slapdash@xxxxxxxxxxxx    VIDEOGAME COLLECTOR!  ||

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