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Displaying Brooks Format Images - How do I chnage palettes that quickly?

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Am I correct in the following?

Assuming that I have preset my scbs for a dynamic palette for 200 scanlines 
and assuming that the retrace starts at scanline 191 and proceeds to 199 
then resumes at scanline 0 and proceeds until scanline 190, and assuming 
that my loading of palettes needs to stay ahead of the lines being drawn, I 
have divided my brooks palettes into 25 subpalette sets corresponding to my 
scbs:

Interleafed sets - 25 sets of 8 - corresponding to scb's for the Brooks 
Image:

8 palettes 0 - 7 - correspond to scanlines 191 to 199 - loaded into place at 
0x9e00
8 palettes 8-15 - correspond to scanlines 0 to 7 - loaded into place at 
0x9f00

8 palettes 0 - 7 - correspond to scanlines 8 to 15 - loaded into place at 
0x9e00
8 palettes 8-15 - correspond to scanlines 16 to 23 - loaded into place at 
0x9f00

Etc.

So assuming that I have the first complete palette in place when the retrace 
starts, and assuming that I load the sub-palette for lines 8-15 when lines 
0-7 start drawing, and that I load the sub-palette for lines 16-23 when 
lines 8-15 start drawing, by polling the Mega II Vertical Counter at 0xc02e, 
I have afew questions:

If my understanding is correct I need to do this extremely quickly (The 
vertical
count changes at 63.7 microsecond intervals) and replace palettes 
continually staying ahead of the retrace during the display of a 3200 color 
image.

Using MainToAux Memory Moves (jsr  $c311) to load these 25 sets of 8 
palettes into place each cycle, will I move slower than the retrace?

Do I also have time to check the keyboard buffer when the gun moves to the 
top again as well as load the subpalette for lines 8-15?

I am at the point in my Brooks Loader Program that I am just getting to 
this. But I know I am not the first to do this, so the other question is:

Is my strategy stupid? Only those of you who have actually programmed a 
brooks loader should probably answer that one:)

Bill 

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Thread

Displaying Brooks Format Images - How do I chnage palettes that quickly? "Bill Buckels" <bbuckels@mts.net> - 2014-01-05 18:22 -0600
  Displaying Brooks Format Images - How do I chnage palettes that quickly? Antoine Vignau <antoine.vignau@laposte.net> - 2014-01-07 01:04 -0800
    Re: Displaying Brooks Format Images - How do I chnage palettes that quickly? "Bill Buckels" <bbuckels@mts.net> - 2014-01-07 05:16 -0600
      Re: Displaying Brooks Format Images - How do I chnage palettes that quickly? Antoine Vignau <antoine.vignau@laposte.net> - 2014-01-07 04:02 -0800
      Re: Displaying Brooks Format Images - How do I chnage palettes that quickly? gids.rs@sasktel.net - 2014-01-07 07:41 -0800
        Re: Displaying Brooks Format Images - How do I chnage palettes that quickly? "Bill Buckels" <bbuckels@mts.net> - 2014-01-09 21:02 -0600
    Re: Displaying Brooks Format Images - How do I chnage palettes that quickly? "Bill Buckels" <bbuckels@mts.net> - 2014-01-07 06:02 -0600
      Re: Displaying Brooks Format Images - How do I chnage palettes that quickly? Antoine Vignau <antoine.vignau@laposte.net> - 2014-01-07 04:03 -0800

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