Path: utzoo!mnetor!uunet!tektronix!tekig!tekig5!wayneck
From: wayneck@tekig5.TEK.COM (Wayne Knapp)
Newsgroups: comp.sys.atari.st
Subject: Re: More info on software color upgrade
Message-ID: <2531@tekig5.TEK.COM>
Date: 14 Mar 88 23:05:20 GMT
References: <2508@tekig5.TEK.COM> <2137@polya.STANFORD.EDU>
Organization: Tektronix Inc., Beaverton, Or.
Lines: 32
Keywords: public domain great graphics

In article <2137@polya.STANFORD.EDU>, rokicki@polya.STANFORD.EDU (Tomas G. Rokicki) writes:
> Try movem.  As in:
> 
> 	movem.l	(a0)+,a2-a5/d0-d7
> 	movem.l a2-a5/d0-d7,(a1)
> 	add.w	#48,a1
> 
> Much faster than
> 
> 	move.l	(a0)+,(a1)+
> 
> repeated 12 times.
> 
> -tom

    Maybe I'm confused and not counting cycles correctly, if so show me where
I going wrong.  But it looks like the move multiple sequence is only 6 cycles
faster than the 12 move.1 (a0)+,(a1)+.  The advantange of the move.l is that
you get a more even color change than the movem gives.  That is every color
change is exactly 20 cycles apart.  Here is what I believe the timings are. 

  	movem.l	(a0)+,a2-a5/d0-d7     # 8 + 8 * 12 = 104
  	movem.l a2-a5/d0-d7,(a1)      #12 + 8 * 12 = 108
  	add.w	#48,a1                #               22
                                                    ----
                                                     234

Where as 12 move.l (a0)+,(a1)+ gives 12 * 20 or 240 cycles.   Is this correct
or am I goofed up.   Thanks for your help.

                                  Wayne Knapp