37 lines
515 B
Plaintext
37 lines
515 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
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;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 STR ,dev/w STR
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( load screen size )
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,00 IOR^ ,width STR^
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,02 IOR^ ,height STR^
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( draw pixel at screen center )
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,0101
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,width LDR^ ,0002 DIV^
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,height LDR^ ,0002 DIV^
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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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IOW^ ( y short )
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IOW^ ( 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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