[Coco] Screen Type 8 code ?

Robert Gault robert.gault at att.net
Sat Jul 18 20:28:59 EDT 2020


Charlie,

More specifically, you want to read portions of the Coco 3 Service manual (p 12 is good) and the 
OS-9 Level Two Operating System manual
(DWSet Windows p 3-12, system calls SS.AScrn Technical Reference p 8-142) to see how to open any 
kind of window.
The Display (an Os-9 command) uses the format of the DWSet command used in assembly code and thus is
Code: 1B 20
Parameters: STY CPX CPY SZX SZY Frg Bkg Bordr
STY: 01   40x24 text
      02   80x24 text
      05   640x192 2 colors
      06   320x192 4 colors
      07   640x192 4 colors
      08   320x192 16 colors

Curtis's sequence is
1B 24 DWEnd turn off current window
1B 20 DWSet start a window
8     type is 320x192x16
0 0   top left corner is 0,0
28 18 lower right corner is 40 bytes wide & 24 bytes deep
0 2 2 palette registers used for colors
1B 21 select window which in this case is Current

As 4 bits are used for 16 colors, that's two pixels per byte on a 16 color screen. The values 28 18 
should be checked.

Robert

L. Curtis Boyle wrote:
> DISPLAY 1B 24 1B 20 8 0 0 28 18 0 2 2 1B 21
> (That’s one way)
>
> L. Curtis Boyle
> curtisboyle at sasktel.net
>
>
>
>> On Jul 18, 2020, at 3:39 PM, coco at jechar.ca wrote:
>>
>>
>> What is the NitrOS9 code to open a 320x192 16 color graphics window
>> Mode 8 ?
>>
>> Charlie
>>
>> -- 
>> Coco mailing list
>> Coco at maltedmedia.com
>> https://pairlist5.pair.net/mailman/listinfo/coco
>>
>



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