67 lines
1.4 KiB
PHP
67 lines
1.4 KiB
PHP
.macro breakpoint ; $02 isn't a valid instruction, the emulator will see this and halt, dump memory contents
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.byte $02
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.endm
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.macro pop ; drops a data stack cell
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inx
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inx
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.endm
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.macro pop2 ; drops 2 data stack cells
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inx
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inx
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inx
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inx
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.endm
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.macro push, cell_high, cell_low ; push a data stack cell
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dex
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dex
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lda \cell_low
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sta 0, x
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lda \cell_high
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sta 1, x
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.endm
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.macro push2 ; push 2 data stack cells
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dex
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dex
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dex
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dex
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.endm
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.macro push_char, char; pushes an ascii character code onto the stack
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lda \char
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push
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sta 0, x ; char low byte
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stz 1, x ; char high byte
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.endm
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.macro push_coords, coord_x, coord_y ; push a set of (x,y) coordinates onto the data stack
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lda \coord_x
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push
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sta 0, x ; low byte
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stz 1,x ; high byte is zero
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lda \coord_y
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push
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sta 0,x ; same here
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stz 1,x
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.endm
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.macro to_r ; pop the top of the stack off and save it in the return (hardware) stack: (n -- )
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lda 1, x
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pha
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lda 0, x
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pha
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pop
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.endm
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.macro from_r ; pop the top of the return stack off and put it on the data stack: ( -- n)
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push
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pla
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sta 0, x
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pla
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sta 1, x
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.endm
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