; Display a 40x96 lo-res image ; Uses the 40x96 page1/page2 every-2-scanline pageflip mode ; as shown in my kfest18 hackfest demo ; 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 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 TEXT = $FB36 ;; Set text mode HOME = $FC58 ;; Clear the text screen WAIT = $FCA8 ;; delay 1/2(26+27A+5A^2) us MAX = 4 lda #$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 ;============================== jsr vapor_lock ; 6+ ; vapor lock returns with us at beginning of hsync in line ; 114 (7410 cycles), so with 5070 lines to go ; GR part bit LORES ; 4 bit SET_GR ; 4 bit FULLGR ; 4 jsr gr_copy_to_current ; 6+ 9292 ; now we have 322 left ; 322 - 12 = 310 ; - 3 for jmp ; 307 ; Try X=9 Y=6 cycles=307 ldy #6 ; 2 loopA: ldx #9 ; 2 loopB: dex ; 2 bne loopB ; 2nt/3 dey ; 2 bne loopA ; 2nt/3 jmp display_loop ; 3 .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 #48 ; 2 outer_loop: bit PAGE0 ; 4 ldx #25 ; 130 cycles with PAGE0 ; 2 page0_loop: ; delay 126+bit dex ; 2 bne page0_loop ; 2/3 bit PAGE1 ; 4 ldx #23 ; 130 cycles with PAGE1 ; 2 page1_loop: ; delay 115+(7 loop)+4 (bit)+4(extra) dex ; 2 bne page1_loop ; 2/3 nop ; 2 lda DRAW_PAGE ; 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 "vapor_lock.s" .include "delay_a.s" pictures: .word apple_low,apple_high .word katahdin_low,katahdin_high .word df_girl_low,df_girl_high .word df_girl2_low,df_girl2_high .include "apple_40_96.inc" .include "katahdin_40_96.inc" .include "df_girl_40_96.inc" .include "df_girl2_40_96.inc"