[Coco] 1bit hsync nasties....

Simon Jonassen simon at roust-it.dk
Thu Jan 23 13:13:20 EST 2014


Hey guys !

There we go.... I told you it was "nasty" code....

I obviously misread the cycle counts from the documentation - looking at the
wrong column....

/Simon :-)
 

-----Oprindelig meddelelse-----
Fra: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] På
vegne af Darren A
Sendt: 23. januar 2014 18:41
Til: CoCoList for Color Computer Enthusiasts
Emne: Re: [Coco] 1bit hsync nasties....

On Thu, Jan 23, 2014 at 10:16 AM, Arthur Flexser wrote:

> Simon, seems like you could save an additional 4 cycles by changing 
> ldb #$00 to clrb in two places, no?  (ldb #$00, decb could also be 
> replaced with ldb #$ff, though that wouldn't save any further cycles 
> compared to clrb, decb.)
>
> Art
>
>
I thought the same thing when I was looking at his code. However it turns
out that this is self-modified code where the immediate data in those
instructions is being changed elsewhere.

And by the way, ldb #xx and eorb #xx are shown as executing in 4 cycles, but
in reality they take only 2.

Darren

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