; Display a 40x48d lo-res image ; Uses the 40x48d page1/page2 every-1-scanline pageflip mode ; by deater (Vince Weaver) end_book: ;=================== ; init screen jsr TEXT jsr HOME bit KEYRESET ;=================== ; init vars lda #0 sta DRAW_PAGE ;=================== ; setup grahics jsr create_update_type1 ;============================= ; Load graphic page0 lda #book_low sta GBASH lda #$c ; load image to $c00 jsr load_rle_gr lda #4 sta DRAW_PAGE jsr gr_copy_to_current ; copy to page1 ; GR part bit PAGE1 bit LORES ; 4 bit SET_GR ; 4 bit FULLGR ; 4 ;============================= ; Load graphic page1 lda #book_high sta GBASH lda #$c ; load image to $c00 jsr load_rle_gr lda #0 sta DRAW_PAGE jsr gr_copy_to_current ; GR part bit PAGE0 ;============================== ; 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 ; now we have 322 left ; 322 - 12 = 310 ; - 3 for jmp ; 307 ; Try X=9 Y=6 cycles=307 ldy #6 ; 2 loopQ: ldx #9 ; 2 loopR: dex ; 2 bne loopR ; 2nt/3 dey ; 2 bne loopQ ; 2nt/3 jmp book_loop ; 3 .align $100 ;================================================ ; Display Loop ;================================================ ; We want to alternate between page1 and page2 every 65 cycles ; vblank = 4550 cycles to do scrolling book_loop: jsr $9000 ; cycle-counted page0/page1 flip code ;====================================================== ; We have 4550 cycles in the vblank, use them wisely ;====================================================== ; do_nothing should be ; 4550 ; -12 -- enter/leave flip code ; -10 -- keypress code ; ======= ; 4528 cycles ;================================= ; do nothing ;================================= ; and take 4528 book_do_nothing: ; Try X=4 Y=174 cycles=4525 R3 lda TEMP ; 3 ldy #174 ; 2 bloop1: ldx #4 ; 2 bloop2: dex ; 2 bne bloop2 ; 2nt/3 dey ; 2 bne bloop1 ; 2nt/3 lda KEYPRESS ; 4 bpl book_no_keypress ; 3 rts ; 6 book_no_keypress: jmp book_loop ; 3