mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-08-14 10:29:46 +00:00
1210 lines
21 KiB
ArmAsm
1210 lines
21 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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FRAMEBUFFER = $00 ; $00 - $0F
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YPOS = $10
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YPOS_SIN = $11
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CH = $24
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CV = $25
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GBASL = $26
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GBASH = $27
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BASL = $28
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BASH = $29
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MASK = $2E
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COLOR = $30
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FRAME = $60
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MB_VALUE = $91
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BIRD_STATE = $E0
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BIRD_DIR = $E1
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DRAW_PAGE = $EE
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LASTKEY = $F1
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PADDLE_STATUS = $F2
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XPOS = $F3
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TEMP = $FA
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TEMPY = $FB
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INL = $FC
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INH = $FD
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OUTL = $FE
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OUTH = $FF
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; Soft Switches
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KEYPRESS= $C000
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KEYRESET= $C010
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SET_GR = $C050 ; Enable graphics
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FULLGR = $C052 ; Full screen, no text
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PAGE0 = $C054 ; Page0
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PAGE1 = $C055 ; Page1
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LORES = $C056 ; Enable LORES graphics
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PADDLE_BUTTON0 = $C061
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PADDL0 = $C064
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PTRIG = $C070
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; ROM routines
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TEXT = $FB36 ;; Set text mode
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HOME = $FC58 ;; Clear the text screen
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WAIT = $FCA8 ;; delay 1/2(26+27A+5A^2) us
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; location we don't care about
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DUMMY = $300
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waterfall_demo:
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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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lda #4
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sta DRAW_PAGE
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sta XPOS
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;===================
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; Mockingboard
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jsr mockingboard_init
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; Enable channel A tone+noise
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ldx #7 ; 2
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lda #$36 ; 2
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sta MB_VALUE ; 3
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jsr write_ay_both ; 6+65
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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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;==============================
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; setup graphics for vapor lock
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;==============================
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; Clear Page0 to all green
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lda #$0
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sta DRAW_PAGE
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lda #$44
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jsr clear_gr
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; Make top half of screen blue, down to line 26
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lda #$11
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ldy #24
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jsr clear_page_loop
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;=====================================================
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; attempt vapor lock
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; by reading the "floating bus" we can see most recently
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; written value of the display
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; we look for $55 (which is the grey line)
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;=====================================================
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; See:
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; Have an Apple Split by Bob Bishop
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; Softalk, October 1982
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; Challenges: each scan line scans 40 bytes.
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; The blanking happens at the *beginning*
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; So 65 bytes are scanned, starting at adress of the line - 25
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; the scan takes 8 cycles, look for 4 repeats of the value
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; to avoid false positive found if the horiz blanking is mirroring
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; the line (max 3 repeats in that case)
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vapor_lock_loop: ; first make sure we have all blue
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lda #$11 ; 2
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zxloop:
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ldx #$04 ; 2
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wiloop:
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cmp $C051 ; 4
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bne zxloop ; 2/3
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dex ; 2
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bne wiloop ; 2/3
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lda #$44 ; now look for our color (4 times) ; 2
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zloop:
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ldx #$04 ; 2
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; what cycle does CMP happen at?
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; while matching match = 4+2+2+3 = 11???
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; if start at x=0, 0, 11, 22, 33 exit at 43
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; if start at x=1, 1, 12, 23, 34 exit at 44
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; if start at x=2, 2, 13, 24, 35 exit at 45
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; if start at x=3, 3, 14, 25, 36 exit at 46
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; if start at x=4, 4, 15, 26, 37 exit at 47
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; if start at x=5, 5, 16, 27, 38 exit at 48
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; if start at x=6, 6, 17, 28, 39 exit at 49
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; if start at x=7, 7, 18, 29, *40 exit at **
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; if start at x=8, 8, 19, 30, *41 exit at **
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; if not match, 2+4+3 = 9, first match = 8
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qloop:
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cmp $C051 ; 4
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bne zloop ; 2/3
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dex ; 2
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bne qloop ; 2/3
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; found first line of black after green, at up to line 26 on screen
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; so we want roughly 22 lines * 4 = 88*65 = 5720 + 4550 = 10270
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; - 65 (for the scanline we missed) = 10205 - 12 = 10193
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jsr gr_copy_to_current ; 6+ 9292
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; 10193 - 9298 = 895
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; Fudge factor (unknown) -30 = 865
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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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; Try X=88 Y=2 cycles=893 R2
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nop ; 2
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ldy #2 ; 2
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loopA:
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ldx #88 ; 2
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loopB:
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dex ; 2
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bne loopB ; 2nt/3
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dey ; 2
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bne loopA ; 2nt/3
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jmp display_loop
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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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; if even, 10 + 9 + display_even + 2 (balance) = 21+display_even
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; if odd 10 + 8 + display_odd + 3 (balance) = 21+display_odd
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; we have 3 (the jmp) + 6 (the rts) - 1 (fallthrough)
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; = 8 cycles that need to be eaten by the vblank
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display_loop:
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inc FRAME ; 5
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lda FRAME ; 3
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and #$10 ; 2
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beq even
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; 2
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lda FRAME ; (nop) ; 3
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jsr display_odd ; 6
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jmp vblank ; 3
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even:
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; 3
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nop ; (nop) ; 2
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jsr display_even ; 6
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jmp vblank ; 3
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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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; -9 letfover from HBLANK code
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; -49 check for keypress
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; -2252 copy screen
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; -2231 draw sprite
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; =============
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; 9 cycles
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; jsr do_nothing ; 6
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; 17 cycles
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inc YPOS ; 5
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nop
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nop
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; inc YPOS ; 5
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; inc YPOS ; 5
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; nop ; 2
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; nop ; 2
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;=========================
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; Clear background
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;=========================
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jsr gr_copy_row22 ; 6+ 2246
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;=========
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; 2252
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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 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 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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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 draw_bird ; 3
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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 keypress
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; 2
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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 display_loop ; 3
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;===================================================
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; key was pressed handling takes 12 + 20 + 11 = 43
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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
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; 2
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nop ; 2
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lda YPOS ; 3-cycle nop
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jmp convoluted ; 3
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; ------ 20 if neither
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is_left:
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; 3
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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 display_loop ; 3
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;=================================
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; do nothing
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;=================================
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; and take 11-6 = 5 cycles to do it
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;do_nothing:
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; Try X=3 Y=1 cycles=22
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; nop ; 2
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; nop ; 2
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; ldy #1 ; 2
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;loop1:
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; ldx #3 ; 2
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;loop2:
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; dex ; 2
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; bne loop2 ; 2nt/3
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; dey ; 2
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; bne loop1 ; 2nt/3
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; rts ; 6
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;==================================
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; HLINE
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;==================================
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; Color in A
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; Y has which line
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hline:
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pha ; 3
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ldx gr_offsets,y ; 4+
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stx hline_loop+1 ; 4
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lda gr_offsets+1,y ; 4+
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clc ; 2
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adc DRAW_PAGE ; 3
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sta hline_loop+2 ; 4
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pla ; 4
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ldx #39 ; 2
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hline_loop:
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sta $5d0,X ; 38 ; 5
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dex ; 2
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bpl hline_loop ; 2nt/3
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rts ; 6
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;==========================
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; Clear gr screen
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;==========================
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; Color in A
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clear_gr:
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ldy #46
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clear_page_loop:
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jsr hline
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dey
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dey
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bpl clear_page_loop
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rts
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gr_offsets:
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.word $400,$480,$500,$580,$600,$680,$700,$780
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.word $428,$4a8,$528,$5a8,$628,$6a8,$728,$7a8
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.word $450,$4d0,$550,$5d0,$650,$6d0,$750,$7d0
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.include "../asm_routines/gr_unrle.s"
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.include "../asm_routines/keypress.s"
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.include "gr_copy.s"
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.include "gr_unrolled_copy.s"
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.include "put_sprite.s"
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.include "mockingboard.s"
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.include "waterfall_page1.inc"
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.include "waterfall_page2.inc"
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.align $100
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.include "tfv_sprites.inc"
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.align $100
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;=================================
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; Display Odd
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;=================================
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; we have 65 cycles per line
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; the first 25 are in hblank
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; we come in already 21 cycles into things
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; so the first scanline is a loss (but that's OK)
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; first scanline: 21+ 2 (from ldy) so need to kill 65-23 = 42
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; second scanline, again kill so 65 killed
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display_odd:
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odd_first_four_lines:
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; line 0
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; 21
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ldy #4 ; 2
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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; line 1, 65 cycles
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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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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nop ; 2
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; line 2, 65 cycles
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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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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nop ; 2
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; line 3, 65 cycles
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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asl DUMMY ; 6
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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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nop ; 2
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odd_twinkle_stars:
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twinkle_loop_odd:
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; line 0
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bit PAGE0 ; 4
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; delay 29
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asl DUMMY ; 6
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asl DUMMY ; 6
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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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nop ; 2
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; falls
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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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; endfalls
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; delay 21
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asl DUMMY ; 6
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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 PAGE1 ; 4
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; delay 29
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asl DUMMY ; 6
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asl DUMMY ; 6
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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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nop ; 2
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; falls
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bit PAGE1 ; 4
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lda YPOS ; 3
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bit PAGE1 ; 4
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; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 3
|
|
bit PAGE1 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE1 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 4
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4 ; 44
|
|
; end falls
|
|
; delay 21 - 7 from loop
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
nop ; 2 ; 58
|
|
|
|
dey ; 2
|
|
beq twinkle_loop_odd_done ;
|
|
; 2
|
|
jmp twinkle_loop_odd ; 3
|
|
twinkle_loop_odd_done:
|
|
|
|
ldy #31 ; 2
|
|
falls_loop_odd:
|
|
|
|
; line 0
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; endfalls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 2
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 3
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 4
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4 ; 44
|
|
; end falls
|
|
; delay 21 - 7 from loop
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
nop ; 2 ; 58
|
|
|
|
dey ; 2
|
|
beq falls_loop_odd_done ;
|
|
; 2
|
|
jmp falls_loop_odd ; 3
|
|
falls_loop_odd_done:
|
|
; 3
|
|
ldy #12 ; 2
|
|
|
|
ground_loop_odd:
|
|
|
|
; line 0
|
|
bit PAGE1 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE1 ; 4
|
|
; endfalls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 2
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 3
|
|
bit PAGE1 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE1 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 4
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4 ; 44
|
|
; end falls
|
|
; delay 21 - 7 from loop
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
nop ; 2 ; 58
|
|
|
|
dey ; 2
|
|
beq ground_loop_odd_done ;
|
|
; 2
|
|
jmp ground_loop_odd ; 3
|
|
ground_loop_odd_done:
|
|
|
|
|
|
; 3
|
|
nop ; 2
|
|
|
|
rts ; 6
|
|
|
|
.align $100
|
|
|
|
;=================================
|
|
; Display Even
|
|
;=================================
|
|
; we have 65 cycles per line
|
|
; the first 25 are in hblank
|
|
; we come in already 21 cycles into things
|
|
; so the first scanline is a loss (but that's OK)
|
|
|
|
; first scanline: 21+ 2 (from ldy) so need to kill 65-23 = 42
|
|
; second scanline, again kill so 65 killed
|
|
|
|
display_even:
|
|
|
|
even_first_four_lines:
|
|
|
|
; we do mockingboard here
|
|
; we have 239 cycles (65*4 = 260 - 21 = 239)
|
|
|
|
; 78+78+2+20 = 178
|
|
; 239 - 178 = 61 to kill
|
|
|
|
; come in with 21
|
|
; 21
|
|
|
|
; kill 61
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda XPOS ; 3
|
|
nop ; 2
|
|
nop ; 2
|
|
|
|
; high = 5 + 12+ 3 = 20
|
|
; medium = 5 + 9 + 6 = 20
|
|
; low = 5 + 9 + 6 = 20
|
|
|
|
lda XPOS ; 3
|
|
cmp #23 ; 2
|
|
bmi check_medium
|
|
; 2
|
|
lda #35 ; 2
|
|
sec ; 2
|
|
sbc XPOS ; 3
|
|
sta YPOS ; (nop) ; 3
|
|
was_low:
|
|
jmp write_volume ; 3
|
|
check_medium:
|
|
; 3
|
|
nop ; 2
|
|
nop ; 2
|
|
cmp #12 ; 2
|
|
bmi was_low
|
|
was_medium:
|
|
; 2
|
|
lda #12 ; 2
|
|
nop ; 2
|
|
|
|
|
|
|
|
|
|
|
|
write_volume:
|
|
; write A volume
|
|
sta MB_VALUE ; 3
|
|
ldx #8 ; 2
|
|
lda #$2 ; 2
|
|
jsr write_ay_both ; 6+65
|
|
;===============
|
|
; 78
|
|
; write noise
|
|
|
|
ldx #6 ; 2
|
|
lda #0 ; 2
|
|
sta MB_VALUE ; 3
|
|
jsr write_ay_both ; 6+65
|
|
;===============
|
|
; 78
|
|
|
|
|
|
; setup loop for next section
|
|
ldy #4 ; 2
|
|
|
|
even_twinkle_stars:
|
|
|
|
twinkle_loop_even:
|
|
|
|
; line 0
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; endfalls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 2
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 3
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 4
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4 ; 44
|
|
; end falls
|
|
; delay 21 - 7 from loop
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
nop ; 2 ; 58
|
|
|
|
dey ; 2
|
|
beq twinkle_loop_even_done ;
|
|
; 2
|
|
jmp twinkle_loop_even ; 3
|
|
twinkle_loop_even_done:
|
|
|
|
ldy #31 ; 2
|
|
falls_loop_even:
|
|
|
|
; line 0
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; endfalls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 2
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 3
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 4
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4 ; 44
|
|
; end falls
|
|
; delay 21 - 7 from loop
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
nop ; 2 ; 58
|
|
|
|
dey ; 2
|
|
beq falls_loop_even_done ;
|
|
; 2
|
|
jmp falls_loop_even ; 3
|
|
falls_loop_even_done:
|
|
; 3
|
|
ldy #12 ; 2
|
|
|
|
ground_loop_even:
|
|
|
|
; line 0
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; endfalls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 2
|
|
bit PAGE1 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE1 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 3
|
|
bit PAGE0 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE0 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE0 ; 4
|
|
; end falls
|
|
; delay 21
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
|
|
; line 4
|
|
bit PAGE1 ; 4
|
|
; delay 29
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
lda YPOS ; 3
|
|
nop ; 2
|
|
; falls
|
|
bit PAGE1 ; 4
|
|
lda YPOS ; 3
|
|
bit PAGE1 ; 4 ; 44
|
|
; end falls
|
|
; delay 21 - 7 from loop
|
|
asl DUMMY ; 6
|
|
asl DUMMY ; 6
|
|
nop ; 2 ; 58
|
|
|
|
dey ; 2
|
|
beq ground_loop_even_done ;
|
|
; 2
|
|
jmp ground_loop_even ; 3
|
|
ground_loop_even_done:
|
|
|
|
|
|
; 3
|
|
nop ; 2
|
|
|
|
rts ; 6
|
|
|