453 lines
7.6 KiB
ArmAsm
453 lines
7.6 KiB
ArmAsm
; Display a 40x96 lo-res image
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; by deater (Vince Weaver) <vince@deater.net>
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appleII_intro:
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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 KEYRESET
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;===================
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; init vars
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lda #0
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sta DRAW_PAGE
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sta DUDE_X
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sta FOREVER_OFFSET
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;=============================
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; Load graphic page0
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lda #<appleII_low
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sta GBASL
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lda #>appleII_low
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sta GBASH
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lda #$c
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jsr load_rle_gr
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;=============================
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; Load graphic page1
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lda #<appleII_high
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sta GBASL
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lda #>appleII_high
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sta GBASH
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lda #$10
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jsr load_rle_gr
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; GR part
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bit PAGE0
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; jsr wait_until_keypressed
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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 to vblank
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; 5070+17030+4550=26650
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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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lda #0 ; 2
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sta DRAW_PAGE ; 3
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jsr gr_clear_all ; 6+ 5454
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lda #4 ; 2
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sta DRAW_PAGE ; 3
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jsr gr_clear_all ; 6+ 5454
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; 26650
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; -12 GR init
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; -5465 clear page0
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; -5465 clear page1
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;==========
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; 15708
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; Try X=29 Y=104 cycles=15705R3
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lda TEMP
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ldy #104 ; 2
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loopA: ldx #29 ; 2
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loopB: 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 ; 3
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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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; We want to alternate between page1 and page2 every 65 cycles
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; vblank = 4550 cycles to do scrolling
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; 2 + 48*( (4+2+25*(2+3)) + (4+2+23*(2+3)+4+5)) + 9)
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; 48*[(6+125)-1] + [(6+115+10)-1]
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display_loop:
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ldy #48 ; 2
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outer_loop:
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bit PAGE1 ; 4
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ldx #25 ; 130 cycles with PAGE0 ; 2
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page0_loop: ; delay 126+bit
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dex ; 2
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bne page0_loop ; 2/3
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bit PAGE0 ; 4
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ldx #23 ; 130 cycles with PAGE1 ; 2
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page1_loop: ; delay 115+(7 loop)+4 (bit)+4(extra)
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dex ; 2
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bne page1_loop ; 2/3
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nop ; 2
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lda DRAW_PAGE ; 3
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dey ; 2
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bne outer_loop ; 2/3
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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:
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; 4550
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; +1 (fallthrough)
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; -2 initial conditions
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; -1174
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; -7 (keypress)
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; -3 (jump)
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; -1243 (play_music)
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; =====
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; 2122 2179
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jsr do_nothing ; 6
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;========================
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; Add 8 to wipe_right
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; Add 12 to wipe_left
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; Add 16 to forever
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; Add 15 to donothing
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ldx DUDE_X ; 3
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cpx #40 ; 2
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bcc wipe_right ; blt ; 3
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; -1
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cpx #80 ; 2
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bcc wipe_left ; blt ; 3
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; -1
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cpx #192 ; 2
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bcc forever ; blt ; 3
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; -1
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;=========================
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; hold steady
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done_done:
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; -1
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;===========================
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; delay 1174-15-3=1156
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; delay
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; Try X=45 Y=5 cycles=1156
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ldy #5 ; 2
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loop11: ldx #45 ; 2
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loop21: dex ; 2
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bne loop21 ; 2nt/3
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dey ; 2
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bne loop11 ; 2nt/3
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jmp intro_wipe_done ; 3
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;=====================
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;=====================
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; wipe right
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;=====================
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;=====================
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; 24*(30+18)-1 +5+3 = 1159
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; 1174-1159-8=7
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; page0 -- copy from $c00
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wipe_right:
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nop ; 2
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nop ; 2
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lda WASTE_CYCLES ; 3
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;=====
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; 7
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page0_loopy:
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lda gr_offsets,Y ; 4+
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sta page0_store_smc+1 ; 4
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sta page0_load_smc+1 ; 4
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lda gr_offsets+1,Y ; 4+
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clc ; 2
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adc #$4 ; 2
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sta page0_store_smc+2 ; 4
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adc #$8 ; 2
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sta page0_load_smc+2 ; 4
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;=====
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; 30
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page0_load_smc:
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lda $1000,X ; 4+
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page0_store_smc:
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sta $1000,X ; 5
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iny ; 2
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iny ; 2
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cpy #48 ; 2
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bne page0_loopy ; 3
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;================
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; 18
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; -1
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inc DUDE_X ; 5
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jmp intro_wipe_done ; 3
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;=====================
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;=====================
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; wipe left
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;=====================
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;=====================
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; 11+ 24*(28+18)-1 +5+3 = 1170
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; 1174-1122-12=40
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; page0 -- copy from $c00
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wipe_left:
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inc WASTE_CYCLES ; 5
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inc WASTE_CYCLES ; 5
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inc WASTE_CYCLES ; 5
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inc WASTE_CYCLES ; 5
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inc WASTE_CYCLES ; 5
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inc WASTE_CYCLES ; 5
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inc WASTE_CYCLES ; 5
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inc WASTE_CYCLES ; 5
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; 40 -> 79 map to 39->0 = 39 - (X-40) = 79-X
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lda #79 ; 2
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sec ; 2
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sbc DUDE_X ; 3
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tax ; 2
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ldy #0 ; 2
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;=====
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; 11
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page1_loopy:
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lda gr_offsets,Y ; 4+
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sta page1_store_smc+1 ; 4
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sta page1_load_smc+1 ; 4
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lda gr_offsets+1,Y ; 4+
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clc ; 2
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sta page1_store_smc+2 ; 4
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adc #$8 ; 2
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sta page1_load_smc+2 ; 4
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;=====
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; 28
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page1_load_smc:
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lda $1000,X ; 4+
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page1_store_smc:
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sta $1000,X ; 5
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iny ; 2
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iny ; 2
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cpy #48 ; 2
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bne page1_loopy ; 3
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;================
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; 18
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; -1
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inc DUDE_X ; 5
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jmp intro_wipe_done ; 3
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;=========================
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; FOREVER
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;==========================
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; F@80, 11,32
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; O@96
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; R@112
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; E@128
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; V@144
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; E@160
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; R@176
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forever:
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; -1
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;===========================
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; forever:
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; 1174 base
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; -16 previous if/else
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; -7 check
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; -18 new_forever
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; -38 colors
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; -14 putchar prep
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; -365 putchar
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; -8 end
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;=====================
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; 708
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txa ; 2
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and #$f ; 2
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beq new_forever ; 3
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; -1
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nop ; 2
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nop ; 2
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nop ; 2
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nop ; 2
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nop ; 2
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nop ; 2
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nop ; 2
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nop ; 2
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jmp write_forever ; 3
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new_forever:
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inc forever_string_smc+1 ; 6
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lda forever_x_smc+1 ; 4
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clc ; 2
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adc #4 ; 2
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sta forever_x_smc+1 ; 4
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;=======
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; 18
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write_forever:
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txa ; 2
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and #$0c ; 2
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tax ; 2
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lda colors_first,X ; 4+
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sta colors_hi ; 4
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lda colors_first+1,X ; 4+
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sta colors_hi+1 ; 4
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lda colors_first+2,X ; 4+
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sta colors_hi+2 ; 4
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lda colors_first+3,X ; 4+
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sta colors_hi+3 ; 4
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;======
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; 38
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; Colors
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; 0 0 0 4
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; 0 0 4 C
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; 0 4 C F
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forever_string_smc:
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lda forever_string ; 4+
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forever_x_smc:
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ldx #7 ; 2
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ldy #32 ; 2
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jsr put_char ; 6+365
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;=======
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; delay
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; Try X=19 Y=7 cycles=708
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ldy #7 ; 2
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loop19: ldx #19 ; 2
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loop29: dex ; 2
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bne loop29 ; 2nt/3
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dey ; 2
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bne loop19 ; 2nt/3
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inc DUDE_X ; 5
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jmp intro_wipe_done ; 3
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;==========================
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;==========================
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intro_wipe_done:
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lda FRAME_PLAY_PAGE ; 3
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cmp #2 ; 2
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beq appleii_done ; 3
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; -1
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; lda KEYPRESS ; 4
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; bpl no_keypress2 ; 3
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; jmp appleii_done
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no_keypress2:
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jsr play_frame_compressed ; 6+1237
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jmp display_loop ; 3
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appleii_done:
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rts
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;.align $100
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;=================================
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; do nothing
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;=================================
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; and take 2122-12 = 2110 cycles to do it
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do_nothing:
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; Try X=21 Y=19 cycles=2110
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ldy #19 ; 2
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loop1: ldx #21 ; 2
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loop2: 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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do_nothing_end:
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forever_string:
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.byte ' ','F','O','R','E','V','E','R'
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colors_first: .byte $00,$00,$00,$00
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colors_second: .byte $00,$04,$40,$00
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colors_third: .byte $40,$4C,$C4,$04
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colors_fourth: .byte $C4,$CF,$FC,$4C
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.if 0
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colors_first: .byte $00,$00,$00,$00
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colors_second: .byte $00,$40,$04,$00
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colors_third: .byte $04,$C4,$4C,$40
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colors_fourth: .byte $4C,$FC,$CF,$C4
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.endif
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.assert >do_nothing = >do_nothing_end, error, "do_nothing crosses page"
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