; Uses the 40x48d page1/page2 every-1-scanline pageflip mode ; self modifying code to get some extra colors (pseudo 40x192 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 DRAW_PAGE = $EE LASTKEY = $F1 PADDLE_STATUS = $F2 TEMP = $FA WHICH = $FB OUTL = $FE OUTH = $FF ; 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 start_rasterbars: ;=================== ; 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 ; 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 ; 5070 + 4550 = 9620 ; 9292 ; 12 ; 6 ; ==== ; 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 display_loop: .include "rasterbars_screen.s" ;====================================================== ; We have 4550 cycles in the vblank, use them wisely ;====================================================== ; 4550 -- VBLANK ; -174 -- raster 16+26+6+126 = 174 ; -10 -- keypress ;======= ; 4366 pad_time: ; we erase, then draw ; doing a blanket erase of all 128 lines would cost 3459 cycles! ; move red ldy red_x ; 4 lda movement_table,Y ; 4 sta red_x ; 4 and #$7f ; 2 tax ; 2 ;========== ; 16 ; draw red lda #$33 ; 2 sta smc_raster_color1_1+1 ; 4 sta smc_raster_color1_2+1 ; 4 lda #$bb ; 2 sta smc_raster_color2_1+1 ; 4 sta smc_raster_color2_2+1 ; 4 lda #$ff ; 2 sta smc_raster_color3_1+1 ; 4 ;============= ; 26 jsr draw_rasterbar ; 6+126 ; Try X=57 Y=15 cycles=4366 ldy #15 ; 2 loop1: ldx #57 ; 2 loop2: dex ; 2 bne loop2 ; 2nt/3 dey ; 2 bne loop1 ; 2nt/3 lda KEYPRESS ; 4 bpl no_keypress ; 3 jmp display_loop no_keypress: jmp display_loop ; 3 ;======================== ; Draw a rasterbar ; unroll as memory is free! haha ;======================== ; X is location ; 2+22+24+24+24+24+6 = 126 draw_rasterbar: ; clear all lines ldy #0 ; 2 ;==== lda y_lookup_l,X ; 4 sta OUTL ; 3 lda y_lookup_h,X ; 4 sta OUTH ; 3 smc_raster_color1_1: lda #$33 ; 2 sta (OUTL),Y ; 6 ;============ ; 22 inx ; 2 lda y_lookup_l,X ; 4 sta OUTL ; 3 lda y_lookup_h,X ; 4 sta OUTH ; 3 smc_raster_color2_1: lda #$bb ; 2 sta (OUTL),Y ; 6 inx ; 2 lda y_lookup_l,X ; 4 sta OUTL ; 3 lda y_lookup_h,X ; 4 sta OUTH ; 3 smc_raster_color3_1: lda #$ff ; 2 sta (OUTL),Y ; 6 inx lda y_lookup_l,X ; 4 sta OUTL ; 3 lda y_lookup_h,X ; 4 sta OUTH ; 3 smc_raster_color2_2: lda #$bb ; 2 sta (OUTL),Y ; 6 inx lda y_lookup_l,X ; 4 sta OUTL ; 3 lda y_lookup_h,X ; 4 sta OUTH ; 3 smc_raster_color1_2: lda #$33 ; 2 sta (OUTL),Y ; 6 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" .align $100 .include "rasterbars_table.s" .include "movement_table.s" .include "gr_copy.s" .include "vapor_lock.s" .include "delay_a.s" pictures: .word k_low,k_high .include "k_40_48d.inc" krg: .byte $0 red_x: .byte $10