711 lines
12 KiB
ArmAsm
711 lines
12 KiB
ArmAsm
; Lo-res cycle-counting water transparency hack
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; by deater (Vince Weaver) <vince@deater.net>
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; Zero Page
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BIRD_STATE = $E0
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BIRD_DIR = $E1
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; location we don't care about
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DUMMY = $300
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waterfall:
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;===================
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; init screen
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; jsr TEXT
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; jsr HOME
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bit PAGE0
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;===================
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; init vars
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lda #0
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sta BIRD_DIR
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sta BIRD_STATE
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sta FRAME
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sta FRAMEH
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lda #1
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sta XPOS
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lda #4
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sta DRAW_PAGE
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;=============================
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; Load foreground to graphic page1 (apple page2)
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lda #$0c
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sta BASH
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lda #$00
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sta BASL ; load image to $c00
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lda #<waterfall_page1
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sta GBASL
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lda #>waterfall_page1
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sta GBASH
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jsr load_rle_gr
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jsr gr_copy_to_current ; copy to page1
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;=============================
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; Load bg to memory
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lda #$0c
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sta BASH
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lda #$00
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sta BASL ; load image to $c00
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lda #<waterfall_page2
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sta GBASL
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lda #>waterfall_page2
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sta GBASH
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jsr load_rle_gr
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sei ; disable interrupt music
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;==============================
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; setup graphics for vapor lock
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;==============================
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jsr vapor_lock ; 6
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; vapor lock returns with us at beginning of hsync in line
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; 114 (7410 cycles), so with 5070 lines to go
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jsr gr_copy_to_current ; 6+ 9292
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; now we have 322 left
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; GR part
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bit LORES ; 4
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bit SET_GR ; 4
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bit FULLGR ; 4
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; 322 - 12 = 310
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; -3 for jmp
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; 307
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; Try X=9 Y=6 cycles=307
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ldy #6 ; 2
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wfloopA:ldx #9 ; 2
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wfloopB:dex ; 2
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bne wfloopB ; 2nt/3
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dey ; 2
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bne wfloopA ; 2nt/3
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jmp wf_display_loop
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wf_jump_table:
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.word (display_even-1)
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.word (display_odd-1)
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.word (display_three-1)
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.word (display_four-1)
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.align $100
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;================================================
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; Display Loop
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;================================================
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; each scan line 65 cycles
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; 1 cycle each byte (40cycles) + 25 for horizontal
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; Total of 12480 cycles to draw screen
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; Vertical blank = 4550 cycles (70 scan lines)
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; Total of 17030 cycles to get back to where was
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; jump_table
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; 38 + display_odd
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; we have 3 (the jmp back)
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; = 3 cycles that need to be eaten by the vblank
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wf_display_loop:
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inc FRAME ; 5
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lda FRAME ; 3
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and #$30 ; 2
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; 0011 0000, so more or less div by 16, 3.75Hz
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lsr ; 2
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lsr ; 2
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lsr ; 2
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tay ; 2 ; 18
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lda wf_jump_table+1,y ; 4
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pha ; 3
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lda wf_jump_table,y ; 4
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pha ; 3
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rts ; 6 ; 38
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wf_display_loop_return:
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vblank:
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;======================================================
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; We have 4550 cycles in the vblank, use them wisely
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;======================================================
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; do_nothing should be 4550
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; -3 letfover from HBLANK code
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; -20 move loop
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; -7 see if done
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; -49 check for keypress
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; -578 copy screen
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; -2231 draw sprite
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; -1038 play music
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; =============
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; 624 cycles
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jsr play_music ; 6+1032
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; Try X=29 Y=11 cycles=1662
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; Try X=123 Y=1 cycles=622 R2
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nop
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ldy #1 ; 2
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wfloopY:ldx #123 ; 2
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wfloopZ:dex ; 2
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bne wfloopZ ; 2nt/3
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dey ; 2
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bne wfloopY ; 2nt/3
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; Move loop = 13
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wf_move_loop:
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lda FRAME ; 3
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and #$07 ; 2
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cmp #4 ; 2
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beq wf_move ; 3
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; -1
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lda $0 ; 3
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lda $0
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nop
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jmp wf_see_if_done ; 3
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wf_move:
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inc XPOS ; 5
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inc BIRD_STATE ; 5
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;============
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; 20
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wf_see_if_done:
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lda XPOS ; 3
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cmp #34 ; 2
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beq wf_exit ; 3
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; -1
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;============
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; 7
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;=========================
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; Clear background
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;=========================
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jsr gr_copy_row22 ; 6+ 572
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;=========
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; 578
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;==========================
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; draw bird sprite
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;==========================
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; 8 prefix
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; bird_walk_right= 14 + 2175 2206 (need 17)
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; bird_stand_right= 13 + 2190 2206 (need 3)
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; bird_walk_left= 15 + 2175 2206 (need 16)
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; bird_stand_left= 14 + 2190 2206 (need 2)
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; call to sprite 17 postfix
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;====================================================
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; 2231
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lda BIRD_STATE ; 3
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and #1 ; 2
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ldx BIRD_DIR ; 3
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bne bird_left
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bird_right:
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; 2
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cmp #1 ; 2
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beq bird_walk_right
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; 2
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bird_stand_right:
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ldx #>bird_rider_stand_right ; 2
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ldy #<bird_rider_stand_right ; 2
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lda YPOS ; nop=3
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jmp wf_draw_bird ; 3
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bird_walk_right:
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; 3
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ldx #>bird_rider_walk_right ; 2
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ldy #<bird_rider_walk_right ; 2
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jmp kill_less_time ; 3
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bird_left:
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; 3
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cmp #1 ; 2
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beq bird_walk_left
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bird_stand_left:
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; 2
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ldx #>bird_rider_stand_left ; 2
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ldy #<bird_rider_stand_left ; 2
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nop ; nop=2
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jmp wf_draw_bird ; 3
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bird_walk_left:
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; 3
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ldx #>bird_rider_walk_left ; 2
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ldy #<bird_rider_walk_left ; 2
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wf_kill_time:
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nop ; 2 ; need to kill 16
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kill_less_time:
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lda YPOS ; nop=3 ; need to kill 14
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lda YPOS ; nop=3
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lda YPOS ; nop=3
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lda YPOS ; nop=3
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nop ; 2
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jmp wf_draw_bird ; 3
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wf_draw_bird:
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stx INH ; 3
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sty INL ; 3
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lda #22 ; 2
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sta YPOS ; 3
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jsr put_sprite ; 6
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;=========
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; 17 + 2190
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;====================
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; Handle keypresses
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; if no keypress, 9
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; if keypress, 6+43 = 49
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lda KEYPRESS ; 4
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bmi wf_keypress
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; 2
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wf_no_keypress:
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; kill 40 cycles
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ldx #0 ; 2
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inc YPOS,X ; 6
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inc YPOS,X ; 6
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inc YPOS,X ; 6
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inc YPOS,X ; 6
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inc YPOS,X ; 6
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inc YPOS,X ; 6
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nop ; 2
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jmp wf_display_loop ; 3
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;===================================================
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; key was pressed handling takes 12 + 20 + 11 = 43
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wf_keypress:
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; 1
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bit KEYRESET ; 4
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inc BIRD_STATE ; 5
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and #$5f ; mask keypress ; 2
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is_it_right:
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cmp #$15 ; right arrow ; 2
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bne is_it_left
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; 2
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inc XPOS ; 5
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lda #0 ; 2
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sta BIRD_DIR ; 3
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lda YPOS ; 3-cycle nop ; 3
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convoluted:
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jmp adjust_xpos ; 3 ; 20 if right
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is_it_left:
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; 5
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cmp #$8 ; left arrow ; 2
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beq is_left ; 3
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; -1
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cmp #0 ; space? ; 2
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bne not_space ; 3
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wf_exit:
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bit KEYRESET
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cli ; re-enable interrupt music
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rts
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; nop ; 2
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; lda YPOS ; 3-cycle nop ; 3
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not_space:
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jmp convoluted ; 3
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; ------ 20 if neither
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is_left:
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dec XPOS ; 5 ; 20 if left
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lda #1 ; 2
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sta BIRD_DIR ; 3
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adjust_xpos:
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lda XPOS ; 3
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and #$1f ; keep in 0-31 range ; 2
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sta XPOS ; 3
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jmp wf_display_loop ; 3
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.align $100
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;=========================================================
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; fast copy rows 22-36 from $C00 to $400
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;=========================================================
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;
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; 7+ 8*[9*7 + 7] + 5 = 572
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.assert >gr_copy_row22 = >gr_copy_row_done, error, "gr_copy_row22 crosses page"
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gr_copy_row22:
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ldy #8 ; 2
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ldx XPOS ; 3
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dex ; 2
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grcr_loop:
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lda $da8,x ; 4
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sta $5a8,x ; 22 ; 5
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lda $e28,x ; 4
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sta $628,x ; 24 ; 5
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lda $ea8,x ; 4
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sta $6a8,x ; 26 ; 5
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lda $f28,x ; 4
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sta $728,x ; 28 ; 5
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lda $fa8,x ; 4
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sta $7a8,x ; 30 ; 5
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lda $c50,x ; 4
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sta $450,x ; 32 ; 5
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lda $cd0,x ; 4
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sta $4d0,x ; 34 ; 5
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inx ; 2
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dey ; 2
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bne grcr_loop ; 3
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; -1
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rts ; 6
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gr_copy_row_done:
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; even odd three four
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;twinkle: 1111 1111 0110 1111
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;falls: 000 010 010 000
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; 000 000 010 010
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; 010 000 000 010
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; 010 010 000 000
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;ground: 0101 1010 1010 0101
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; PAGE0=54 PAGE1=55
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;=================================
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; Display Even
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;=================================
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display_even:
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lda #$55 ; 2
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; twinkle 11 falls 0011 ground 0101
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sta wf_modify1+1 ; 4
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sta wf_modify2+1 ; 4
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sta wf_modify5+1 ; 4
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sta wf_modify6+1 ; 4
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sta wf_modify8+1 ; 4
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sta wf_modify10+1 ; 4
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lda #$54
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; twinkle 11 falls 0011 ground 0101
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sta wf_modify3+1 ; 4
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sta wf_modify4+1 ; 4
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sta wf_modify7+1 ; 4
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sta wf_modify9+1 ; 4
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jmp first_four_lines ; 3
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;============
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; 47
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;=================================
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; Display Odd
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;=================================
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display_odd:
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lda #$55 ; 2
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; twinkle 11 falls 1001 ground 1010
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sta wf_modify1+1 ; 4
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sta wf_modify2+1 ; 4
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sta wf_modify3+1 ; 4
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sta wf_modify6+1 ; 4
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sta wf_modify7+1 ; 4
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sta wf_modify9+1 ; 4
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lda #$54
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; twinkle 11 falls 1001 ground 1010
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sta wf_modify4+1 ; 4
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sta wf_modify5+1 ; 4
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sta wf_modify8+1 ; 4
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sta wf_modify10+1 ; 4
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jmp first_four_lines ; 3
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;============
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; 47
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;=================================
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; Display Three
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;=================================
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display_three:
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lda #$55 ; 2
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; twinkle 00 falls 1100 ground 1010
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sta wf_modify3+1 ; 4
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sta wf_modify4+1 ; 4
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sta wf_modify7+1 ; 4
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sta wf_modify9+1 ; 4
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lda #$54
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; twinkle 00 falls 1100 ground 1010
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sta wf_modify1+1 ; 4
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sta wf_modify2+1 ; 4
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sta wf_modify5+1 ; 4
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sta wf_modify6+1 ; 4
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sta wf_modify8+1 ; 4
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sta wf_modify10+1 ; 4
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jmp first_four_lines ; 3
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;============
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; 47
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;=================================
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; Display Four
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;=================================
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display_four:
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lda #$55 ; 2
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; twinkle 11 falls 0110 ground 0101
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sta wf_modify1+1 ; 4
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sta wf_modify2+1 ; 4
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sta wf_modify4+1 ; 4
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sta wf_modify5+1 ; 4
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sta wf_modify8+1 ; 4
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sta wf_modify10+1 ; 4
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lda #$54
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; twinkle 11 falls 0110 ground 0101
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sta wf_modify3+1 ; 4
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sta wf_modify6+1 ; 4
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sta wf_modify7+1 ; 4
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sta wf_modify9+1 ; 4
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jmp first_four_lines ; 3
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;============
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; 47
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.align $100
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first_four_lines:
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; line 0-3 = 65*4 = 260
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; -38
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; -47
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; -2
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; -2
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; -25
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;=========================
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; 146
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lda #146 ; 2
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jsr delay_a ; 25+146
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ldy #4 ; 2
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twinkle_stars:
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twinkle_loop:
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; page1 for 4 lines, 65 - 4 = 61 -2 = 59 - 25 = 34
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; line 0
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wf_modify1:
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bit PAGE1 ; 4
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lda #34 ; 2
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jsr delay_a ; 25+34
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; line 1
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bit PAGE1 ; 4
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lda #34 ; 2
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jsr delay_a ; 25+34
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; line 2
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bit PAGE1 ; 4
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lda #34 ; 2
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jsr delay_a ; 25+34
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; line 3
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wf_modify2:
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bit PAGE1 ; 4
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lda #27 ; 2
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jsr delay_a ; 25+27
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; below: 7 if not zero
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; 7 (including ldy later) if is zero
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dey ; 2
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beq twinkle_loop_done ; 3
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;-1
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jmp twinkle_loop ; 3
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twinkle_loop_done:
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ldy #31 ; 2
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falls_loop:
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;=== line 0
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bit PAGE0 ; 4
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; delay 31
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lda #4 ; 2
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jsr delay_a ; 25+4
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; delay 11
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wf_modify3:
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bit PAGE0 ; 4
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lda YPOS ; 3
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bit PAGE0 ; 4
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; delay 19
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nop ; 2
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nop ; 2
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asl DUMMY ; 6
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asl DUMMY ; 6
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lda YPOS ; 3
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;=== line 1
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bit PAGE0 ; 4
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; delay 31
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lda #4 ; 2
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jsr delay_a ; 25+4
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; delay 11
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wf_modify4:
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bit PAGE0 ; 4
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lda YPOS ; 3
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bit PAGE0 ; 4
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; delay 19
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nop ; 2
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nop ; 2
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asl DUMMY ; 6
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asl DUMMY ; 6
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lda YPOS ; 3
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;=== line 2
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bit PAGE0 ; 4
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; delay 31
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lda #4 ; 2
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jsr delay_a ; 25+4
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; delay 11
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wf_modify5:
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bit PAGE1 ; 4
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lda YPOS ; 3
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bit PAGE0 ; 4
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; delay 19
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nop ; 2
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nop ; 2
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asl DUMMY ; 6
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asl DUMMY ; 6
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lda YPOS ; 3
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|
|
;== line 3
|
|
bit PAGE0 ; 4
|
|
; delay 31
|
|
lda #4 ; 2
|
|
jsr delay_a ; 25+4
|
|
|
|
; delay 11
|
|
wf_modify6:
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4 ; 46
|
|
|
|
; delay 21 - 7 from loop
|
|
nop ; 2
|
|
nop ; 2
|
|
asl DUMMY ; 6
|
|
nop ; 2 ; 58
|
|
|
|
dey ; 2
|
|
beq falls_loop_done ; 3
|
|
; -1
|
|
jmp falls_loop ; 3
|
|
falls_loop_done:
|
|
|
|
ldy #12 ; 2
|
|
|
|
ground_loop:
|
|
|
|
;==== line 0
|
|
wf_modify7:
|
|
bit PAGE0 ; 4
|
|
; delay 61
|
|
lda #34 ; 2
|
|
jsr delay_a ; 25+34
|
|
|
|
;==== line 1
|
|
wf_modify8:
|
|
bit PAGE1 ; 4
|
|
; delay 61
|
|
lda #34 ; 2
|
|
jsr delay_a ; 25+34
|
|
|
|
;==== line 2
|
|
wf_modify9:
|
|
bit PAGE0 ; 4
|
|
; delay 61
|
|
lda #34 ; 2
|
|
jsr delay_a ; 25+34
|
|
|
|
;=== line 3
|
|
wf_modify10:
|
|
bit PAGE1 ; 4
|
|
; delay 54
|
|
lda #27 ; 2
|
|
jsr delay_a ; 25+27
|
|
|
|
dey ; 2
|
|
beq ground_loop_done ; 3
|
|
; -1
|
|
jmp ground_loop ; 3
|
|
ground_loop_done:
|
|
nop ; 2
|
|
|
|
jmp wf_display_loop_return ; 3
|
|
|
|
|
|
; Moved to megademo.s
|
|
;.include "waterfall_page1.inc"
|
|
;.include "waterfall_page2.inc"
|