; Display fancy Fireworks ; Uses the 40x48d page1/page2 every-1-scanline pageflip mode ; by deater (Vince Weaver) ; Zero Page FRAMEBUFFER = $00 ; $00 - $0F YPOS = $10 YPOS_SIN = $11 CH = $24 CV = $25 GBASL = $26 GBASH = $27 BASL = $28 BASH = $29 FRAME = $60 BLARGH = $69 HGR_COLOR = $E4 DRAW_PAGE = $EE LASTKEY = $F1 PADDLE_STATUS = $F2 TEMP = $FA WHICH = $FB ; Soft Switches KEYPRESS= $C000 KEYRESET= $C010 SET_GR = $C050 ; Enable graphics FULLGR = $C052 ; Full screen, no text PAGE0 = $C054 ; Page0 PAGE1 = $C055 ; Page1 LORES = $C056 ; Enable LORES graphics PADDLE_BUTTON0 = $C061 PADDL0 = $C064 PTRIG = $C070 ; ROM routines HGR = $F3E2 HPLOT0 = $F457 TEXT = $FB36 ;; Set text mode HOME = $FC58 ;; Clear the text screen WAIT = $FCA8 ;; delay 1/2(26+27A+5A^2) us COLORTBL= $F6F6 MAX = 3 jsr draw_fireworks ;================================== ;================================== lda #$ff sta WHICH start_over: inc WHICH lda WHICH cmp #MAX bne in_range lda #0 sta WHICH in_range: ;=================== ; init screen jsr TEXT jsr HOME bit KEYRESET ;=================== ; init vars lda #0 sta DRAW_PAGE ;============================= ; Load graphic page0 lda #$0c sta BASH lda #$00 sta BASL ; load image to $c00 lda WHICH asl asl ; which*4 tay lda pictures,Y sta GBASL lda pictures+1,Y sta GBASH jsr load_rle_gr lda #4 sta DRAW_PAGE jsr gr_copy_to_current ; copy to page1 ; GR part bit PAGE1 bit LORES ; 4 bit SET_GR ; 4 bit FULLGR ; 4 jsr wait_until_keypressed ;============================= ; Load graphic page1 lda #$0c sta BASH lda #$00 sta BASL ; load image to $c00 lda WHICH asl asl ; which*4 tay lda pictures+2,Y sta GBASL lda pictures+3,Y sta GBASH jsr load_rle_gr lda #0 sta DRAW_PAGE jsr gr_copy_to_current ; GR part bit PAGE0 jsr wait_until_keypressed ;============================== ; setup graphics for vapor lock ;============================== ; Clear Page0 lda #$0 sta DRAW_PAGE lda #$44 jsr clear_gr ; Make screen half green lda #$11 ldy #24 jsr clear_page_loop ;===================================================== ; attempt vapor lock ; by reading the "floating bus" we can see most recently ; written value of the display ; we look for $55 (which is the grey line) ;===================================================== ; See: ; Have an Apple Split by Bob Bishop ; Softalk, October 1982 ; Challenges: each scan line scans 40 bytes. ; The blanking happens at the *beginning* ; So 65 bytes are scanned, starting at adress of the line - 25 ; the scan takes 8 cycles, look for 4 repeats of the value ; to avoid false positive found if the horiz blanking is mirroring ; the line (max 3 repeats in that case) vapor_lock_loop: ; first make sure we have all zeroes LDA #$11 zxloop: LDX #$04 wiloop: CMP $C051 BNE zxloop DEX BNE wiloop LDA #$44 ; now look for our border color (4 times) zloop: LDX #$04 qloop: CMP $C051 BNE zloop DEX BNE qloop ; found first line of black after green, at up to line 26 on screen ; so we want roughly 22 lines * 4 = 88*65 = 5720 + 4550 = 10270 ; - 65 (for the scanline we missed) = 10205 - 12 = 10193 jsr gr_copy_to_current ; 6+ 9292 ; 10193 - 9298 = 895 ; Fudge factor (unknown) -30 = 865 ; GR part bit LORES ; 4 bit SET_GR ; 4 bit FULLGR ; 4 ; Try X=88 Y=2 cycles=893 R2 nop ldy #2 ; 2 loopA: ldx #88 ; 2 loopB: dex ; 2 bne loopB ; 2nt/3 dey ; 2 bne loopA ; 2nt/3 jmp display_loop .align $100 ;================================================ ; Display Loop ;================================================ ; each scan line 65 cycles ; 1 cycle each byte (40cycles) + 25 for horizontal ; Total of 12480 cycles to draw screen ; Vertical blank = 4550 cycles (70 scan lines) ; Total of 17030 cycles to get back to where was ; We want to alternate between page1 and page2 every 65 cycles ; vblank = 4550 cycles to do scrolling ; 2 + 48*( (4+2+25*(2+3)) + (4+2+23*(2+3)+4+5)) + 9) ; 48*[(6+125)-1] + [(6+115+10)-1] display_loop: ldy #96 ; 2 outer_loop: bit PAGE0 ; 4 ldx #12 ; 65 cycles with PAGE0 ; 2 page0_loop: ; delay 61+bit dex ; 2 bne page0_loop ; 2/3 ; bit(4) -1(fallthrough) + loop*5 -1(fallthrouh)+4 extra = 61 ; 5L = 55 bit PAGE1 ; 4 ldx #11 ; 65 cycles with PAGE1 ; 2 ; page1_loop: ; delay 115+(7 loop)+4 (bit)+4(extra) dex ; 2 bne page1_loop ; 2/3 dey ; 2 bne outer_loop ; 2/3 ;====================================================== ; We have 4550 cycles in the vblank, use them wisely ;====================================================== ; do_nothing should be 4550+1 -2-9 -7= 4533 jsr do_nothing ; 6 lda KEYPRESS ; 4 bpl no_keypress ; 3 jmp start_over no_keypress: jmp display_loop ; 3 ;================================= ; do nothing ;================================= ; and take 4533-6 = 4527 cycles to do it do_nothing: ; Try X=4 Y=174 cycles=4525 R2 nop ; 2 ldy #174 ; 2 loop1: ldx #4 ; 2 loop2: dex ; 2 bne loop2 ; 2nt/3 dey ; 2 bne loop1 ; 2nt/3 rts ; 6 ;================================== ; HLINE ;================================== ; Color in A ; Y has which line hline: pha ; 3 ldx gr_offsets,y ; 4+ stx hline_loop+1 ; 4 lda gr_offsets+1,y ; 4+ clc ; 2 adc DRAW_PAGE ; 3 sta hline_loop+2 ; 4 pla ; 4 ldx #39 ; 2 hline_loop: sta $5d0,X ; 38 ; 5 dex ; 2 bpl hline_loop ; 2nt/3 rts ; 6 ;========================== ; Clear gr screen ;========================== ; Color in A clear_gr: ldy #46 clear_page_loop: jsr hline dey dey bpl clear_page_loop rts gr_offsets: .word $400,$480,$500,$580,$600,$680,$700,$780 .word $428,$4a8,$528,$5a8,$628,$6a8,$728,$7a8 .word $450,$4d0,$550,$5d0,$650,$6d0,$750,$7d0 .include "../asm_routines/gr_unrle.s" .include "../asm_routines/keypress.s" .include "gr_copy.s" .include "random16.s" .include "fw.s" pictures: .word bg_final_low,bg_final_high .include "background_final.inc"