36 lines
487 B
Plaintext
36 lines
487 B
Plaintext
( screen )
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:dev/r fff8 ( std read port )
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:dev/w fff9 ( std write port )
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;width 2 ;height 2
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|0100 @RESET
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( set read/write to dev/screen )
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#01 DUP =dev/r =dev/w
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( load screen size )
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#00 IOR2 =width
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#02 IOR2 =height
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( draw pixel at screen center )
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#0101
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~width #0002 DIV2
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~height #0002 DIV2
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,putpixel JSR
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BRK
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|c000 @FRAME BRK
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@putpixel
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IOW2 ( y short )
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IOW2 ( x short )
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IOW ( color byte )
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IOW ( redraw byte )
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RTS
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|d000 @ERROR BRK
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|FFFA .RESET .FRAME .ERROR
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