[Coco] Ideas for a Graphics Project, part 2

Robert Gault robert.gault at worldnet.att.net
Tue Oct 25 16:28:03 EDT 2005


Not exactly the same. If you look at the memory map for a Coco3, you 
will see a single MMU block $60000-$67FFF for high resolution graphics. 
There is no highres equivalent to PMODEn,m where m can be changed.

If you have more memory than 128K on a Coco3, then you can make use of 
any memory below $68000 for high resolution graphics. You can manipulate 
the system to swap blocks and get similar effects to the BALL program.

Roger Taylor's Projector series of programs swaps three highres graphic 
screens to increase the number of on-screen colors into the thousands. 
John Kowalski (Sockmaster) does something similar (HiColor) with two 
screens.

There probably are other examples but I can't think of them offhand.

Robert Emery wrote:
> Excellent info, thanks Robert. Are there any similar programs for the CoCo3?
> Seems like they all rely on palette cycling, but it should be possible to set
> up a few graphic pages on a 512K machine and flip through them, possibly
> cycling the palette at the same time for some advanced looking animation.
> 
> Bob
> 
> --- Robert Gault <robert.gault at worldnet.att.net> wrote:
> 
> 
>>The POKEs actually tells Basic that the starting address of a Basic 
>>program should be $6E00. When BALL is reloaded, there is then room for 
>>the required PMODE4 screens.
>>
>>If the program were revised for Coco3 use where the Basic code is in 
>>RAM, a better way would be to replace line 5 with
>>5 WIDTH32:POKE&H9692,17:PCLEAR16
>>With the above, it will not be necessary to reload the program. The POKE 
>>tells Basic that a PCLEAR16 is legal, which automatically relocates the 
>>program so that there is sufficient space for the command
>>PMODE3,13 to work.
>>
>>Robert Emery wrote:
>>
>><snip>
>>
>>>BALL.BAS is an unrelated program from the Rainbow which uses page flipping
>>
>>to
>>
>>>simulate a 3D moving graphic. To run it, you must first LOAD it and LIST5
>>
>>(the
>>
>>>first line.) Enter the POKEs in the REM statement, then reload the program
>>
>>and
>>
>>>run it. The POKEs set up an extra PMODE4 page for Basic.
>>>
>>>cheers,
>>>Bob
>>
>>
>>-- 
>>Coco mailing list
>>Coco at maltedmedia.com
>>http://five.pairlist.net/mailman/listinfo/coco
>>
> 
> 
> 
> 
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