Trevor Merritt
e29ac45c84
scroll left and right work in stdef and hidef adds octo test roms adds schip fonts to memory
75 lines
1.0 KiB
Plaintext
75 lines
1.0 KiB
Plaintext
###########################################
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#
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# A modular stack data structure using
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# a v0-based calling convention.
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# vf is used as a working temporary
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# register because it is "fragile".
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# maximum stack size is 256 bytes.
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#
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###########################################
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# the first value is the pointer index
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: stack 0 0 0 0 0 0 0 0 0
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: push
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# modifies vf, v0
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# takes argument in v0
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# stack[++stack[0] + 1] := v0
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i := stack
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vf := v0
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load v0
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i += v0
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v0 := vf
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save v0
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i := stack
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load v0
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v0 += 1
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i := stack
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save v0
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;
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: pop
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# modifies vf, v0
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# returns result in v0
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# v0 := stack[stack[0]-- + 1]
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i := stack
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load v0
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v0 += -1
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vf := v0
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i := stack
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save v0
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i += vf
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load v0
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;
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###########################################
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#
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# Usage Example:
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#
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###########################################
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: print
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# takes an arg in v0
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i := hex v0
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sprite va vb 5
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va += 6
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;
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: main
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va := 3
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vb := 3
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v0 := 5 push
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v0 := 3 push
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v0 := 1 push
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pop print
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v0 := 9 push
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pop print
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pop print
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pop print
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# should print '1935'
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