mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-11-01 01:06:33 +00:00
185 lines
3.7 KiB
ArmAsm
185 lines
3.7 KiB
ArmAsm
;===============================================
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; Move Letters
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;===============================================
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; Normal P0 =6+13+2+22+46+37 = 126
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; Normal P1 =6+13+2+22+46+37 = 126
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; End of line =6+13+2+22+46+9+(28) = 126
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; Next line =6+13+5+14+34+(26+28) = 126
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; done entirely =6+13+5+(6+42+26+28) = 126
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; Waiting =6+7+(11+6+42+26+28) = 126
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; all forced to be 126
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move_letters:
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ldy WAITING ; 3
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beq not_waiting ; 3
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;============
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; 6
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;-1
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dec WAITING ; 5
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jmp wait_it_out ; 3
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;===========
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; 7
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not_waiting:
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; load letter from pointer, save into LETTER
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ldy #0 ; 2
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lda (LETTERL),Y ; 5
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sta LETTER ; 3
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; if high bit set, is special case
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bmi letter_special ; 3
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;==========
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; 13
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; just regular letter
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;-1
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lda LETTERY ; get letter Y ; 3
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bmi letter_page1
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;==========
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; 2
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letter_page0: ; -1
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asl ; map to memory address ; 2
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tay ; 2
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lda gr_offsets,Y ; lookup low-res memory address ; 4
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sta BASL ; store out low byte of addy ; 3
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lda gr_offsets+1,Y ; look up high byte ; 4
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sta BASH ; 3
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lda #0 ; cycle-killer ; 2
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jmp letter_erase ; 3
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;==========
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; 22
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letter_page1:
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asl ; map to memory address ; 2
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tay ; 2
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lda gr_offsets,Y ; lookup low-res memory address ; 4
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sta BASL ; store out low byte of addy ; 3
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lda gr_offsets+1,Y ; look up high byte ; 4
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clc ; 2
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adc #$4 ; adjust to page1 ; 2
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sta BASH ; 3
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;==========
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; 22
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;============================
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letter_erase:
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ldy LETTERX ; nop ; 3
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nop ; nop ; 5
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ldy #0 ; erase old char with space ; 2
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lda #' '|$80 ; 2
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ldy LETTERX ; 3
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sta (BASL),Y ; 6
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dey ; draw new char ; 2
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sty LETTERX ; 3
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lda LETTER ; 3
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ora #$80 ; 2
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ldy LETTERX ; 3
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sta (BASL),Y ; 6
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lda LETTERX ; see if we are at destination ; 3
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cmp LETTERD ; 3
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beq letter_next ; 3
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;===========
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; 46
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;-1
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lda #0 ; 2
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lda #0 ; 2
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jmp waste_28 ; 3
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;==========
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; 9
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letter_next:
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clc ; 16-bit inc letter pointer ; 2
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lda LETTERL ; 3
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adc #1 ; 2
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sta LETTERL ; 3
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lda LETTERH ; 3
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adc #0 ; 2
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sta LETTERH ; 3
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inc LETTERD ; inc destination X ; 5
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lda #39 ; start at right of screen ; 2
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sta LETTERX ; 3
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rts ; 6
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;===========
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; 37
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letter_special:
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cmp #$ff ; handle FF, we're done ; 2
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beq letter_done ; 3
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;==========
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; 5
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; -1
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and #$7f ; clear top ; 2
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sta WAITING ; this is waiting value ; 3
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ldy #1 ; otherwise, Y,X pair ; 2
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lda (LETTERL),Y ; get Y, put in LETTERY ; 5
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sta LETTERY ; 3
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;===========
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; 14
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iny ; get dest ; 2
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lda (LETTERL),Y ; 5
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sta LETTERD ; put in LETTERD ; 3
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clc ; skip 3 bytes to begin of letters ; 2
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lda LETTERL ; 16-bit add ; 3
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adc #3 ; 2
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sta LETTERL ; 3
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lda LETTERH ; 3
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adc #0 ; 2
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sta LETTERH ; 3
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lda LETTERH ; waste ; 3
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jmp waste_26 ; 3
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;===========
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; 34
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wait_it_out:
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; wait 11
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inc BLARGH ; 5
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lda LETTERH ; 3
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lda LETTERH ; 3
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letter_done:
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lda LETTERH ; 3
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lda LETTERH ; 3
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waste_42:
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ldx #0 ; 2
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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waste_26:
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ldx #0 ; 2
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ldx #0 ; 2
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ldx #0 ; 2
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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waste_28:
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ldx #0 ; 2
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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inc BLARGH ; 5
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rts ; 6
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