;================================ ; spacebars gameplay ;================================ level6_saturn: ;=================== ; init screen bit KEYRESET ;=================== ; init vars lda #15 sta XPOS lda #38 sta YPOS lda #0 sta FRAMEH ;============================= ; Load graphic hgr lda #background_hgr sta LZ4_SRC+1 lda #<(background_hgr_end-8) ; skip checksum at end sta LZ4_END lda #>(background_hgr_end-8) ; skip checksum at end sta LZ4_END+1 lda #<$2000 sta LZ4_DST lda #>$2000 sta LZ4_DST+1 jsr lz4_decode ;================== ; setup framebuffer lda #0 sta ZPOS ; lda #$12 ; sta FRAMEBUFFER+0 ; lda #$3f ; sta FRAMEBUFFER+1 ; lda #$56 ; sta FRAMEBUFFER+2 ; lda #$78 ; sta FRAMEBUFFER+3 ; lda #$9A ; sta FRAMEBUFFER+4 ; lda #$BC ; sta FRAMEBUFFER+5 ; lda #$DE ; sta FRAMEBUFFER+6 ; lda #$F0 ; sta FRAMEBUFFER+7 ; lda #$12 ; sta FRAMEBUFFER+8 ; lda #$3f ; sta FRAMEBUFFER+9 ; lda #$56 ; sta FRAMEBUFFER+10 ; lda #$78 ; sta FRAMEBUFFER+11 ; lda #$9A ; sta FRAMEBUFFER+12 ;============================= ; Load graphic page1 $800 lda #4 sta DRAW_PAGE lda #$22 jsr clear_gr ;============================= ; Load graphic page2 $c00 lda #8 sta DRAW_PAGE lda #$00 jsr clear_gr lda #score_text sta OUTH jsr move_and_print lda #0 sta DRAW_PAGE ; GR part bit PAGE0 ;============================== ; 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 ; so we have 5070 + 4550 = 9620 to kill jsr gr_copy_to_current ; 6+ 9292 ; now we have 322 left ; GR part bit LORES ; 4 bit SET_GR ; 4 bit FULLGR ; 4 ; 322 - 12 = 310 ; - 3 for jmp ; 307 ; Try X=9 Y=6 cycles=307 ldy #6 ; 2 sbloopA:ldx #9 ; 2 sbloopB:dex ; 2 bne sbloopB ; 2nt/3 dey ; 2 bne sbloopA ; 2nt/3 jmp sb_begin_loop .align $100 ;================================================ ; Spacebars 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 sb_begin_loop: sb_display_loop: ; 1 2 3 ;0123456789012345678901234567890123456789 ;LEVEL: 6 LIVES: 2 SCORE: 01978 HI: 02018 ; 0-7 = text mode ; 8-87 = hgr ; 88 - 168 = split ; 169 - 191 = gr ; 8 lines of text mode ldy #8 ; 2 sb_text_loop: bit SET_TEXT ; 4 lda #29 ; 2 jsr delay_a ; 25+29 dey ; 2 bne sb_text_loop ; 3 ;================ ; 65 ; -1 sb_hgr_loop: ; delay 80*65 = 5200 ; 2180 ; -2 ; +1 ; -8 ;========================= ; 3011 bit SET_GR ; 4 bit HIRES ; 4 ; draw sprite at same time lda #>ship_forward ; 2 sta INH ; 3 lda #