ys2-intro/loader/samples/minexample/minexample.s

.feature c_comments
.include "../../build/loadersymbols-c64.inc"

.ZEROPAGE
.org $10
bmp_delay: .res 1
bmp_addr: .res 2
bmp_ptr: .res 2
scr_ptr_lo: .res 1
scr_ptr: .res 2
cram_ptr: .res 2
chr_count: .res 1
vbl: .res 1
frame: .res 1
cur_frame: .res 1
frame_delay: .res 1
frame_until: .res 1
text_ptr: .res 2
timer: .res 2
timer_limit: .res 2
timer_reached: .res 2
timer_mode: .res 1
enable_music: .res 1
temp: .res 3

aart_lz_buffer := $fd00
.include "lz_zp.asm"

CODE_START_ADDR = $e000

.segment "CODE"

ZP=$e0
offset          = ZP+0
ZX0_src         = ZP+2
ZX0_dst         = ZP+4
bitr            = ZP+6
pntr            = ZP+7


    .org $080d

copy_start:
    sei
    lda #$35
    sta $01

    lda #<CODE_START_ADDR
    sta $fc
    lda #>CODE_START_ADDR
    sta $fd

    lda #<code_start
    sta $fa
    lda #>code_start
    sta $fb

    ldy #0
    ldx #>(code_end-CODE_START_ADDR)
    beq :+++
:
    lda ($fa), y
    sta ($fc), y
    iny
    bne :-
    inc $fb
    inc $fd
    dex
    bne :-
    beq :+
:
    lda ($fa), y
    sta ($fc), y
    iny
:
    cpy #<(code_end-CODE_START_ADDR)
    bne :--

    lda #$36
    sta $01
    cli
    jsr install
    sei
    lda #$35
    sta $01
    jmp CODE_START_ADDR

    .res loadraw - *
.incbin "../../build/loader-c64.prg", 2

    .res install - *
.incbin "../../build/install-c64.prg", 2

code_start:
    .org CODE_START_ADDR

    sei
    lda #$0b
    sta $d011
    lda #0
    sta $d020
    sta ZX0_dst+0
    sta enable_music
    jsr load_font
    jsr init_2x
    jsr clr_txt
    ldx #<copyright
    ldy #>copyright
    jsr write_txt3
    ldx #$00
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode

    ldx #<badguy
    ldy #>badguy
    jsr load_8000_zx02_2000

:
    lda timer_reached
    beq :-

    ldx #$90
    ldy #$01
    jsr txt_fade_out

    sei
    jsr set_irq_badguy

    lda #1
    sta $d01a
    sta bmp_delay
    jsr init_bmp

    lda #0
    sta vbl

    cli

    jsr intro

    lda #$0b
    sta $d011

    sei
    ldx #<introname
    ldy #>introname
    lda #$10
    jsr load_8000_zx02

    ldx #<song0name
    ldy #>song0name
    lda #$a0
    jsr load_8000_zx02

    lda #<fake_kernal_irq
    sta $fffe
    lda #>fake_kernal_irq
    sta $ffff
    inc enable_music

    jsr run_nufli_bmp
    sei
    jsr init_2x
    lda #$0b
    sta $d011

    jsr clr_txt
    ldx #<story_writ
    ldy #>story_writ
    jsr write_txt3
    ldx #$30
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode

    ldx #<towername
    ldy #>towername
    jsr load_8000_zx02_2000

:
    lda timer_reached
    beq :-

    ldx #$b8
    ldy #$01
    jsr txt_fade_out

    jsr init_bmp

    lda #0
    sta vbl

    lda #$11
    sta frame_until
    jsr wait_frame_until_2x

    ldx #$6c
:
    jsr wait_frame
    jsr wait_frame
    dex
    bpl :-

    lda #$0b
    sta $d011

    jsr clr_txt
    ldx #<scenario_writ
    ldy #>scenario_writ
    jsr write_txt2
    ldx #$80
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode

    ldx #<towerbeamname
    ldy #>towerbeamname
    jsr load_8000_zx02_2000

:
    lda timer_reached
    beq :-

    ldx #$90
    ldy #$01
    jsr txt_fade_out

    jsr init_bmp

    lda #0
    sta vbl

    lda #$0d
    sta frame_until
    jsr wait_frame_until_2x
    lda bmp_addr
    sta temp
    lda bmp_addr+1
    sta temp+1
    lda cur_frame
    sta temp+2

    ldx #17
:
    txa
    pha
    lda temp+2
    sta cur_frame
    lda temp
    sta bmp_addr
    lda temp+1
    sta bmp_addr+1
    lda #$0d+3
    sta frame_until
    jsr wait_frame_until_2x    
    pla
    tax
    dex
    bpl :-
    
    lda #$0b
    sta $d011

    jsr clr_txt
    ldx #<prog_writ
    ldy #>prog_writ
    jsr write_txt2
    ldx #$a8
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode

    ldx #<fieldname
    ldy #>fieldname
    jsr load_8000_zx02_2000

:
    lda timer_reached
    beq :-

    ldx #$48
    ldy #$01
    jsr txt_fade_out

    jsr init_bmp

    lda #0
    sta vbl

    lda #$08
    sta frame_until
    jsr wait_frame_until_2x
    lda bmp_addr
    sta temp
    lda bmp_addr+1
    sta temp+1
    lda cur_frame
    sta temp+2

    ldx #2
:
    txa
    pha
    lda temp+2
    sta cur_frame
    lda temp
    sta bmp_addr
    lda temp+1
    sta bmp_addr+1
    lda #$08+8
    sta frame_until
    jsr wait_frame_until_2x    
    pla
    tax
    dex
    bpl :-


    lda #0
    sta vbl
    lda #$27
    sta frame_until
    jsr wait_frame_until_2x    

    ldx #25
:
    jsr wait_frame
    dex
    bpl :-

    lda #$0b
    sta $d011

    jsr clr_txt
    ldx #<gart_writ
    ldy #>gart_writ
    jsr write_txt5
    ldx #$80
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode

    ldx #<fallingstarname
    ldy #>fallingstarname
    jsr load_8000_zx02_2000

:
    lda timer_reached
    beq :-

    ldx #$48
    ldy #$01
    jsr txt_fade_out

    jsr init_bmp

    lda #$1d
    sta frame_until
    jsr wait_frame_until_2x

    ldx #5
:
    jsr wait_frame
    dex
    bpl :-

    lda #$0b
    sta $d011

    jsr clr_txt
    ldx #<music_writ
    ldy #>music_writ
    jsr write_txt4
    ldx #$80
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode

    ldx #<lilianame
    ldy #>lilianame
    jsr load_8000_zx02_2000

:
    lda timer_reached
    beq :-

    ldx #$10
    ldy #$01
    lda #8*11
    jsr txt_fade_out_offset

    ldx #$c4
    ldy #$01
    jsr init_timer

    jsr init_bmp

    lda #$08
    sta frame_until
    jsr wait_frame_until_2x

:
    lda timer_reached
    beq :-

    lda #$0b
    sta $d011

    jsr clr_txt
    ldx #<scene_writ
    ldy #>scene_writ
    jsr write_txt3
    ldx #$80
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode

    ldx #<liliaheroname
    ldy #>liliaheroname
    jsr load_8000_zx02_2000

:
    lda timer_reached
    beq :-

    ldx #$20
    ldy #$01
    jsr txt_fade_out

    jsr init_bmp

    ldx #4
:
    lda #0
    sta vbl
    lda #60
:
    cmp vbl
    bne :-
    dex
    bpl :--

part_9:
    ; $0400-$07ff buffer 0 tilemap
    ; $2000-$3fff buffer 0 bitmap
    ; $4000-$5fff buffer 1 bitmap
    ; $6000-$63ff buffer 1 tilemap
    ; $6400-$6417 next buffer CRAM
    ; $7000-$77ff tileset bitmap
    ; $7800-$78ff tileset tile colors
    ; $7900-$79ff tileset CRAM colors
    ; $9000-      compressed tilemap

    jsr clr_txt
    ldx #<art_direct
    ldy #>art_direct
    jsr write_txt2
    ldx #$c0
    ldy #$01
    jsr init_timer

    lda #1
    sta timer_mode

    ldx #<islandname
    ldy #>islandname
    lda #$70
    jsr load_8000_zx02
    ldx #<islandmapname
    ldy #>islandmapname
    jsr loadraw
    ldx #0
    ldy #$90
    jsr LZ_init_decomp

:
    lda timer_reached
    beq :-

    ldx #$90
    ldy #$01
    lda #8
    jsr txt_fade_out_offset

    lda #0
    sta $d011
    jsr clear_2bufs

    ; set up sprites to cover scrolling
    lda #$ff
    ldx #0
:   sta $2000,x
    sta $4000,x
    inx
    bne :-
    .repeat 4, I
        ldx #I*48+$58
        stx $d000+I*2
        stx $d008+I*2
    .endrepeat
    ldx #6
:
    lda #$42
    sta $d001,x
    lda #$d7
    sta $d009,x
    dex
    dex
    bpl :-
    ldx #7
:
    lda #$80
    sta $07f8,x
    lda #0
    sta $63f8,x
    sta $d027,x
    dex
    bpl :-
    stx $d01d
    stx $d015
    inx
    stx $d010
    stx $d017
    stx $d01b
    stx $d01c
    stx frame

    lda #$18
    sta $d018
    lda #<((17+4)*40+$408)
    sta text_ptr
    lda #>((17+4)*40+$408)
    sta text_ptr+1
    ldx #16
:
    lda #0
    lda text_ptr
    sec
    sbc #40
    sta text_ptr
    sta scr_ptr
    sta cram_ptr
    sta bmp_ptr
    lda text_ptr+1
    sbc #0
    sta text_ptr+1
    sta scr_ptr+1
    ; carry is always set here
    adc #$d8-$04-1
    sta cram_ptr+1
    adc #<(($20>>3)-$d8)
    asl bmp_ptr
    rol a
    asl bmp_ptr
    rol a
    asl bmp_ptr
    rol a
    sta bmp_ptr+1
    stx temp+1
    jsr drawrow
    ldx temp+1
    dex
    bpl :-
    lda #0
    sta cram_ptr
    lda #$64
    sta cram_ptr+1
:
    lda $d011
    bpl :-
    lda #$38
    sta $d011
    lda #$18
    sta $d016
    lda #3
    sta timer_mode
@loop:
    lda #0
    sta vbl
    lda frame
    cmp #$e1
    bcc :+
    jmp @finish
:
    and #1
    tax
    jsr copybuf
    jsr drawrow
:
    lda vbl
    cmp #32
    bcc :-
    ; B U M   R U S H   C R A M C O P Y F U N K
    ldy #23
:   .repeat 16, I
        lda $d808+(19-I)*40,y
        sta $d808+(20-I)*40,y
    .endrepeat
    lda $6400,y
    sta $d808+4*40,y
    dey
    bpl :-
    inc frame
    lda frame
    lsr a
    lda #$18
    ldx #3
    bcc :+
    lda #$80
    ldx #2
:
    sta $d018
    stx $dd00
    jmp @loop

@finish:
    ldx #$a8
    ldy #$01
    jsr init_timer
:
    lda timer_reached
    beq :-
    lda #$0b
    sta $d011
    lda #0
    sta $d015
    lda #3
    sta $dd00

    ; we run out of space before the fixed location vector return now
    jmp part_10

drawrow:
    ldy #0
charloop:
    sty temp
    lda #$70>>3
    sta bmp_addr+1
    jsr LZ_get_byte
    tax
    asl a
    rol bmp_addr+1
    asl a
    rol bmp_addr+1
    asl a
    rol bmp_addr+1
    sta bmp_addr
    ldy #0
    .repeat 8, I
        lda (bmp_addr),y
        sta (bmp_ptr),y
        iny
    .endrepeat
    clc
    lda bmp_ptr
    adc #8
    sta bmp_ptr
    bne :+
    inc bmp_ptr+1
:
    ldy temp
    lda $7800,x
    sta (scr_ptr),y
    lda $7900,x
    sta (cram_ptr),y
    iny
    cpy #24
    bne charloop
    rts

intro:
    lda #0
    jsr sfx_init

    lda #7
    sta frame_until
    jsr wait_frame_until

    lda #64
    sta frame_delay
    jsr wait_loop

    lda #1
    jsr sfx_init

    ldx #<darmtower_txt
    ldy #>darmtower_txt
    jsr upload_text
    ldx #<(darmtower_txt+40)
    ldy #>(darmtower_txt+40)
    jsr upload_text_bottom

    lda #50*5
    sta frame_delay
    jsr wait_loop

    jsr clear_text

    lda #$0d
    sta frame_until
    jsr wait_frame_until

    ldx #<adol_win
    ldy #>adol_win
    jsr upload_text
    ldx #<(adol_win+40)
    ldy #>(adol_win+40)
    jsr upload_text_bottom

    lda #50*5
    sta frame_delay
    jsr wait_loop

    jsr clear_text
    ldx #<too_bad_txt
    ldy #>too_bad_txt
    jsr upload_text

    lda #50*5
    sta frame_delay
    jsr wait_loop

    jsr clear_text

    lda #$13
    sta frame_until
    jsr wait_frame_until

    lda #0
    jsr sfx_init

    lda #$1a
    sta frame_until
    jsr wait_frame_until

    lda #120
    sta frame_delay
    jmp wait_loop

wait_frame:
@loop:
    bit $d011
    bpl @loop
@loop2:
    bit $d011
    bmi @loop2
    rts

init_2x:
    lda #127
    sta $dc0d

    and $d011
    sta $d011

    lda $dc0d
    lda $dd0d

    lda #<irq_music
    sta $fffe
    lda #>irq_music
    sta $ffff

    lda #$0b
    sta $d011
    lda #$00
    sta $d012

position_2x_to_display:
    lda #50
position_2x:
:
    bit $d011
    bpl :-
:
    bit $d011
    bmi :-
:
    cmp $d012
    bne :-

    lda #0
    sta $d01a
    sta $dc0e

    lda #$63; <(985248/100)
    sta $dc04
    lda #$26; >(985248/100)
    sta $dc05
    lda #$11
    sta $dc0e

    lda $dc0d
    and #$81
    sta $dc0d

    lda #$40
    sta $dc0c

    lda #$81
    sta $dc0d

@loop:
    bit $d011
    bpl @loop
@loop2:
    bit $d011
    bmi @loop2
    cli
    rts

init_timer:
    lda #0
    sta timer_reached
    sta timer_mode
    sta timer
    sta timer+1
    stx timer_limit
    sty timer_limit+1
    rts

fade_cols:
    .byte 0, 0
    .byte $0, $0, $0, $0, $b, $c, $f, $1
    .res 32-10, $1

irq_music:
	pha
    txa
    pha
    tya
    pha

    lda $dd00
    and #3
    sta @dd00_arc+1
    and #3
    sta $dd00

    inc vbl

    ;inc $d020
    lda enable_music
    beq :+
    jsr $a003
:
    ;dec $d020

    lda timer_mode
    cmp #1
    bne :+
    lda timer+1
    bne :+
    lda timer
    lsr
    lsr
    lsr
    tax
    lda fade_cols, x
    sta $d021
:
    lda timer_mode
    cmp #2
    bne :+
    lda timer+1
    bne :+
    lda timer
    lsr
    lsr
    lsr
    eor #31
    tax
    lda fade_cols, x
    sta $d021
:

    inc timer
    bne :+
    inc timer+1
:
    lda timer
    sec
    sbc timer_limit
    lda timer+1
    sbc timer_limit+1
    bcc :+
    lda #1
    sta timer_reached
:
    lda timer_mode
    cmp #3
    bne @timer_done
    lda vbl
    lsr a
    bcs @timer_done
    lsr a
    and #7
    ora #$38
    sta $d011

@timer_done:

@dd00_arc:
    lda #0
    sta $dd00

    pla
    tay
    pla
    tax
    pla
    jmp $dc0c
  

fake_kernal_irq:
	pha
    txa
    pha
    tya
    pha
    tsx
    lda $0104, x
    and #$10
    beq :+
    jmp ($0314)
:
    jmp ($0314) ; fuck you

wait_loop:
@loop2:
    lda vbl
    beq @loop2

    lda #0
    sta vbl

    jsr sfx_play

    dec frame_delay
    lda frame_delay
    beq :+
    jmp @loop2
:
    rts

wait_frame_until:
@loop:
    lda vbl
    beq @loop

    lda #0
    sta vbl

    lda cur_frame
    cmp #2
    bcc :+
    jsr sfx_play
:

    dec bmp_delay
    bpl :+
    jsr update_bmp
:

    lda cur_frame
    cmp frame_until
    beq :+

    jmp @loop
:
    rts

wait_frame_until_2x:
@loop:
    lda vbl
    cmp #2
    bcc @loop

    lda #0
    sta vbl

    dec bmp_delay
    bpl :+
    jsr update_bmp
:

    lda cur_frame
    cmp frame_until
    beq :+
    jmp @loop
:
    rts

init_bmp:
    lda #$0b
    sta $d011
    lda #$19
    sta $d018
    lda #$d8
    sta $d016

    lda $4710
    lsr
    lsr
    lsr
    lsr
    sta $d020

    lda $4710
    and #$0f
    sta $d021

    lda #0
    sta cur_frame
    sta bmp_delay

    lda #$11
    sta bmp_addr
    lda #$47
    sta bmp_addr+1

    ldx #0
:
    .repeat 4, I
        lda $3f40+(I*250), x
        sta $400+(I*250), x
        lda $4328+(I*250), x
        sta $d800+(I*250), x
    .endrepeat
    inx
    cpx #250
    bne :-

    lda #$3b
    sta $d011
    rts

inc_bmp_addr:
    inc bmp_addr
    bne :+
    inc bmp_addr+1
:
    rts

update_bmp:
    ldy #0
    sty scr_ptr
    sty cram_ptr
    lda (bmp_addr), y
    jsr inc_bmp_addr
    sta chr_count
    cmp #0 ; tfw flags update in inc_bmp_addr
    bne @skip_frame_end
    lda (bmp_addr), y
    jsr inc_bmp_addr
    sta bmp_delay
    inc cur_frame
    rts    
@skip_frame_end:

    lda (bmp_addr), y   
    sta bmp_ptr
    iny
    lda (bmp_addr), y   
    clc
    adc #$20
    sta bmp_ptr+1

    iny
    lda (bmp_addr), y   
    sta scr_ptr_lo
    iny
    lda (bmp_addr), y   
    clc
    adc #$04
    sta scr_ptr+1
    clc
    adc #$d8-$04
    sta cram_ptr+1

    ldy #0
    lda bmp_addr
    clc 
    adc #4
    sta bmp_addr
    bcc :+
    inc bmp_addr+1
:

    ldx #0
@loop:
    ldy #0
    lda (bmp_addr), y
    sta (bmp_ptr), y
    iny 
    lda (bmp_addr), y
    sta (bmp_ptr), y
    iny 
    lda (bmp_addr), y
    sta (bmp_ptr), y
    iny 
    lda (bmp_addr), y
    sta (bmp_ptr), y
    iny 
    lda (bmp_addr), y
    sta (bmp_ptr), y
    iny 
    lda (bmp_addr), y
    sta (bmp_ptr), y
    iny 
    lda (bmp_addr), y
    sta (bmp_ptr), y
    iny 
    lda (bmp_addr), y
    sta (bmp_ptr), y

    lda bmp_ptr
    clc
    adc #8
    sta bmp_ptr
    bcc :+
    inc bmp_ptr+1
:

    ldy #8
    lda (bmp_addr), y
    ldy scr_ptr_lo
    sta (scr_ptr), y
    
    ldy #9
    lda (bmp_addr), y
    ldy scr_ptr_lo
    sta (cram_ptr), y

    inc scr_ptr_lo
    bne :+
    inc scr_ptr+1
    inc cram_ptr+1
:

    lda bmp_addr
    clc
    adc #10
    sta bmp_addr
    bcc :+
    inc bmp_addr+1
:

    dec chr_count
    ldx chr_count
    bne @loop
    jmp update_bmp

irq_badguy:
    pha

    pha
    pla
    pha
    pla
    pha
    pla
    lda #$1b
    sta $d011
    lda #$c8
    sta $d016
    lda #$13
    sta $d018
    lda #1
    sta $d021

    lda #<irq_badguy2
    sta $fffe
    lda #>irq_badguy2
    sta $ffff
    lda #$fb
    sta $d012

    asl $d019
    pla
    rti

irq_badguy2:
    pha

    inc vbl
    lda #$3b
    sta $d011
    lda #$d8
    sta $d016
    lda #$19
    sta $d018
    lda #0
    sta $d021

    lda #<irq_badguy
    sta $fffe
    lda #>irq_badguy
    sta $ffff
    lda #$d2
    sta $d012

    asl $d019
    pla
    rti

set_irq_badguy:
    lda #127
    sta $dc0d

    and $d011
    sta $d011

    lda $dc0d
    lda $dd0d

    lda #<irq_badguy
    sta $fffe
    lda #>irq_badguy
    sta $ffff
    
    lda #$1b
    sta $d011
    lda #$d2
    sta $d012
    rts

badguy:             .byte "badguy",0
fontname:           .byte "font",0
song0name:          .byte "song0", 0
song1name:          .byte "song1", 0
introname:          .byte "intrbmp", 0
towername:          .byte "tower", 0
towerbeamname:      .byte "towerbm", 0
fieldname:          .byte "field", 0
fallingstarname:    .byte "fallstar", 0
lilianame:          .byte "lilia", 0
liliaheroname:      .byte "lilhero", 0
islandname:         .byte "island", 0
islandmapname:      .byte "islandmap", 0
cloudsname:         .byte "clouds", 0


darmtower_txt:
    .byte "    darm's tower has fallen silent.     "
    .byte "    what should we do?                  "

adol_win:
    .byte "      ", 34, "it must be adol, let's see       "
    .byte "      how far he'll get!", 34, "               "

too_bad_txt:
    .byte "            as you command.             "

upload_text:
    stx text_ptr
    sty text_ptr+1

    ldy #39
:
    lda (text_ptr), y
    clc
    adc #$60
    sta $748, y
    dey
    bpl :-
    rts

upload_text_bottom:
    stx text_ptr
    sty text_ptr+1

    ldy #39
:
    lda (text_ptr), y
    clc
    adc #$60
    sta $748+40+40, y
    dey
    bpl :-
    rts

clear_text:
    lda #$80
    ldy #39
:
    sta $748, y
    sta $748+40+40, y
    dey
    bpl :-
    rts

run_nufli_bmp:
    lda #$01
    sta $81
    lda #$29
    sta $80
    lda #0
    sta $d01a
    asl $d019
    jsr $a000
    cli
    jsr $3000
@loop:
    bit $d011
    bpl @loop
    jsr $a003
@loop2:
    bit $d011
    bmi @loop2
    lda #0
    sta $d020
    sta $d021
    jsr $a003
    lda $80
    bne :+
    dec $81
:
    dec $80
    lda $81
    cmp #$ff
    beq :+
    jmp @loop
:
    lda #0
    sta $d015
    rts


.res $ea31-*, $ff
    ;asl $d019
    pla
    tay
    pla
    tax
    pla
    rti

.res $ea81-*, $ff
    ;asl $d019
    pla
    tay
    pla
    tax
    pla
    rti

.include "sfx.asm"
.include "zx02.asm"
.include "thcmod_lz.asm"

zx02_8000:
    pha
    jmp :+

load_8000_zx02_2000:
    lda #$20
load_8000_zx02:
    pha
    jsr loadraw
:
    lda #0
    sta ZX0_src
    sta ZX0_dst
    lda #$80
    sta ZX0_src+1
    pla
    jmp zx02

load_font:
    beq :+
    pha
:
    ldx #<fontname
    ldy #>fontname
    jsr fileexists
    bcs :-
    ldx #<fontname
    ldy #>fontname
    jmp loadraw

part_10:
    ; the sprite data is embedded into first few bitmap pixels
    ; which are hidden by black border attributes
@y = 93
    jsr clr_txt
    ldx #<total_direct
    ldy #>total_direct
    jsr write_txt2
    ldx #$c0
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode

    ldx #<cloudsname
    ldy #>cloudsname
    jsr load_8000_zx02_2000
:
    lda timer_reached
    beq :-

    ldx #$48
    ldy #$01
    lda #$40
    jsr txt_fade_out_offset

    jsr init_bmp
    ldx #0
    stx $d010
    stx $d017
    stx $d01d
    stx $d025
    stx frame
    dex
    stx $d01b
    stx $d01c
    lda #11
    sta $d026
    lda #@y+48
    jsr position_2x
    lda #0
    sta vbl
    ; draw top half
@loop:
    bit $d011
    bpl @loop
    ldx #0
    ldy #0
    lda frame
    bpl :+
    jmp @finish
:
    cmp #$74
    bcc :+
    lda #$74
:
    pha
:
    clc
    adc @sprxs,x
    sta $d000,y
    sta temp
    lda @sprys,x
    sta $d001,y
    txa
    ora #$80
    sta $7f8,x
    lda @sprcols,x
    sta $d027,x
    lda temp
    iny
    iny
    inx
    cpx #8
    bcc :-
    lda #$ff
    sta $d015

    ; draw bottom half
:
    bit $d011
    bmi :-
    lda #@y+37
:
    cmp $d012
    bcs :-

    ldx #0
    ldy #0
    pla
    clc
:
    adc @sprxs+8,x
    sta $d000,y
    sta temp
    lda @sprys+8,x
    sta $d001,y
    txa
    ora #$88
    sta $7f8,x
    lda @sprcols+8,x
    sta $d027,x
    lda temp
    iny
    iny
    inx
    cpx #6
    bcc :-

    lda vbl
    and #15
    bne :+
    inc frame
:
    jmp @loop

@sprxs:
    .byte 48, <-24, 24, 24, <-64, 24, 24, 24
    .byte 48-40, 24, 24, 24, <-44, 24

@sprys:
    .byte @y-8, @y, @y, @y, @y+21, @y+21, @y+21, @y+21
    .byte @y+42, @y+42, @y+42, @y+42, @y+63, @y+63

@sprcols:
    .byte 2, 5, 5, 5, 14, 14, 14, 6
    .byte 2, 2, 2, 9, 2, 2

@finish:
    lda #$0b
    sta $d011
    lda #0
    sta $d015

    jsr clr_txt
    ldx #<produced
    ldy #>produced
    jsr write_txt2
    ldx #$c0
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode
:
    lda timer_reached
    beq :-

    ldx #$48
    ldy #$01
    lda #8*11
    jsr txt_fade_out_offset

part_11:
    jsr clr_txt
    ldx #<presented
    ldy #>presented
    jsr write_txt1
    ldx #$c0
    ldy #$01
    jsr init_timer
    lda #1
    sta timer_mode

    ; ldx #<liliatalkname
    ; ldy #>liliatalkname
    ; jsr load_8000_zx02_2000
:
    lda timer_reached
    beq :-

    ; tell the music to end and wait
:
    lda #1
    jsr $a006
    cmp #17
    bne :-

    ldx #$00
    ldy #$01
    lda #8*11
    jsr txt_fade_out_offset
:
    lda timer_reached
    beq :-

    jmp * ; TEMP

    ; load new music
    lda #0
    sta enable_music
    ldx #<song1name
    ldy #>song1name
    lda #$a0
    jsr load_8000_zx02

    sei
    jsr set_irq_badguy
    inc enable_music
    cli

    jsr clr_txt
    ldx #<turn_disk
    ldy #>turn_disk
    jsr write_txt1
    
    jmp end

clear_2bufs:
    ldy #$44
    .byte $2c ; skip next instruction
clear_buf:
    ldy #$20
    lda #$20
    sta @dst+2
    lda #0
    tax
:
    sta $400,x
    sta $500,x
    sta $600,x
    sta $700,x
    inx
    bne :-
@dst:
    sta $2000,x
    inx
    bne @dst
    inc @dst+2
    dey
    bne @dst
    rts

copybuf:
    lda @bsrclo,x
    sta bmp_addr
    lda @bsrchi,x
    sta bmp_addr+1
    lda @bdstlo,x
    sta bmp_ptr
    lda @bdsthi,x
    sta bmp_ptr+1
    lda @tsrclo,x
    sta text_ptr
    lda @tsrchi,x
    sta text_ptr+1
    lda @tdstlo,x
    sta scr_ptr
    lda @tdsthi,x
    sta scr_ptr+1
    ldx #16
@loop:
    ldy #23
:   lda (text_ptr),y
    sta (scr_ptr),y
    dey
    bpl :-
    ldy #191
:   lda (bmp_addr),y
    sta (bmp_ptr),y
    dey
    bne :-
    lda (bmp_addr),y
    sta (bmp_ptr),y
    ; math dumb cpu be struggling a lot here
    lda text_ptr
    sec
    sbc #40
    sta text_ptr
    bcs :+
    dec text_ptr+1
:
    lda scr_ptr
    sec
    sbc #40
    sta scr_ptr
    bcs :+
    dec scr_ptr+1
:
    lda bmp_addr
    sec
    sbc #<320
    sta bmp_addr
    bcs :+
    dec bmp_addr+1
:
    dec bmp_addr+1
    lda bmp_ptr
    sec
    sbc #<320
    sta bmp_ptr
    bcs :+
    dec bmp_ptr+1
:
    dec bmp_ptr+1
    dex
    bne @loop
    rts

@bsrclo:    .lobytes (15+4)*320+$2040, (15+4)*320+$4040
@bsrchi:    .hibytes (15+4)*320+$2040, (15+4)*320+$4040
@bdstlo:    .lobytes (16+4)*320+$4040, (16+4)*320+$2040
@bdsthi:    .hibytes (16+4)*320+$4040, (16+4)*320+$2040
@tsrclo:    .lobytes (15+4)*40+$0408, (15+4)*40+$6008
@tsrchi:    .hibytes (15+4)*40+$0408, (15+4)*40+$6008
@tdstlo:    .lobytes (16+4)*40+$6008, (16+4)*40+$0408
@tdsthi:    .hibytes (16+4)*40+$6008, (16+4)*40+$0408

copyright:
.byte "                  ys ^                  "
.byte "         copyright 1988 falcom          "
.byte "           all right reserved           "

story_writ:
.byte "           story written by             "
.byte "                takahiro ohura          "
.byte "                tomoo yamane            "

scenario_writ:
.byte "         scenario written by            "
.byte "              tomoyoshi miyazaki        "

prog_writ:
.byte "          programmed by                 "
.byte "               masaya hashimoto         "

gart_writ:
.byte "        graphic arts designed by        "
.byte "              takahiro ohura            "
.byte "              ayano koshiro             "
.byte "              kazuhiko tsuzuki          "
.byte "              tomoo yamane              "

music_writ:
.byte "           music composed by            "
.byte "                mieko ishikawa          "
.byte "                yuzo koshiro            "
.byte "                hideya nagata           "

scene_writ:
.byte "         scene set by                   "
.byte "               seigo oketani            "
.byte "               yoshihiko kurata         "

art_direct:
.byte "           art directed by              "
.byte "                seigo oketani           "

total_direct:
.byte "          total directed by             "
.byte "               masaya hashimoto         "

produced:
.byte "           produced by                  "
.byte "                masayuki katoh          "

presented:
.byte "          presented by falcom           "

turn_disk:
.byte "       insert datadisk in drive 8       "

clr_txt:
    lda #$80
    ldx #0
:
    .repeat 4, I
        sta $400+(I*250), x
    .endrepeat
    inx
    cpx #250
    bne :-
    lda #0
    ldx #0
:
    .repeat 4, I
        sta $d800+(I*250), x
    .endrepeat
    inx
    cpx #250
    bne :-
    lda #$13
    sta $d018
    lda #$1b
    sta $d011
    rts

write_txt5:
    stx text_ptr
    sty text_ptr+1
    ldy #0
    lda #<($400+8*40)
    ldx #>($400+8*40)
    jsr write_txt_to
    lda #<($400+10*40)
    ldx #>($400+10*40)
    jsr write_txt_to
    lda #<($400+12*40)
    ldx #>($400+12*40)
    jsr write_txt_to
    lda #<($400+14*40)
    ldx #>($400+14*40)
    jsr write_txt_to
    lda #<($400+16*40)
    ldx #>($400+16*40)
    jmp write_txt_to

write_txt4:
    stx text_ptr
    sty text_ptr+1
    ldy #0
    lda #<($400+9*40)
    ldx #>($400+9*40)
    jsr write_txt_to
    lda #<($400+11*40)
    ldx #>($400+11*40)
    jsr write_txt_to
    lda #<($400+13*40)
    ldx #>($400+13*40)
    jsr write_txt_to
    lda #<($400+15*40)
    ldx #>($400+15*40)
    jmp write_txt_to

write_txt3:
    stx text_ptr
    sty text_ptr+1
    ldy #0
    lda #<($400+10*40)
    ldx #>($400+10*40)
    jsr write_txt_to
    lda #<($400+12*40)
    ldx #>($400+12*40)
    jsr write_txt_to
    lda #<($400+14*40)
    ldx #>($400+14*40)
    jmp write_txt_to

write_txt2:
    stx text_ptr
    sty text_ptr+1
    ldy #0
    lda #<($400+11*40)
    ldx #>($400+11*40)
    jsr write_txt_to
    lda #<($400+13*40)
    ldx #>($400+13*40)
    jmp write_txt_to

write_txt1:
    stx text_ptr
    sty text_ptr+1
    ldy #0
    lda #<($400+12*40)
    ldx #>($400+12*40)
    ; fall through

write_txt_to:
    sta @dst+1
    stx @dst+2
    ldx #0
:
    lda (text_ptr), y
    sec
    sbc #$20
    ora #$80
@dst:
    sta $400, x
    iny
    inx
    cpx #40
    bne :-
    rts

txt_fade_out:
    lda #0
txt_fade_out_offset:
    pha
    jsr init_timer
    pla
    sta timer
    lda #2
    sta timer_mode
:
    lda timer_reached
    beq :-
    rts

    .res ((*+$ff)&$ff00|2)-*
end:
    ldx #<fontname
    ldy #>fontname
    jsr fileexists
    bcc end
    jmp code_start

code_end: