; moe-bius - zx/tsfm player
        ; --atemka 14.o8.2o25 
        
        device zxspectrum128

ivt         equ     0x8000
isr         equ     0x8181
codestart   equ     0x8080

reg_buffer  equ     0x5B00  ; basic variables :meatjob:

        EMPTYTAP "player.tap"

        ; IM2 vector table - all 257 values for floating bus condition
        org ivt
        block 257, (isr >> 8)                 ; isr at 0x8181

        ; dummy ISR (vblank synchronization is done by HALT)
        org isr
stack_top:
        ei
        ret

        ; entrypoint
start:
        di
        ld          sp, stack_top

        ; set IM2 vector table to 0x80
        ld          a, high ivt
        ld          i, a
        im          2

        ; prefill register buffer to prevent crashes
        ld          hl, reg_buffer
        ldi         [hl], 0x2F :  ldi [hl], 0xFF
        ldi         [hl], 0x2D :  ldi [hl], 0xFF
        ld          [hl], -1

        ; enable interrupts
        ei
.loop:
        halt
        ld          a, 1 : out (0xfe), a
        ld          bc, 0xFFFD
        ld          de, 0x00C0
        ld          a,  0b11111000
        out         (c), a
        ld          hl, reg_buffer
        call        player.reg_out
        ld          a, 2 : out (0xfe), a
        ld          a,  0b11111001
        ld          b,  0xFF
        out         (c), a
        inc         hl
        call        player.reg_out
        ld          a, 3 : out (0xfe), a
        ld          iy, reg_buffer
        call        player.play_tick
        xor         a    : out (0xfe), a

        ; and jump to next frame
        xor a       : ld  bc, 0x7FFD : out (c), a   ; map fast page to fix 128k AY ports contention
        jp          .loop

; ----------------------------------------------------
        ; vu meters
        ; orig by natt, rewritten by me

vumeter:
        ld      a, 0
        call    .get_address
        ld      [start.vu0], hl
        ld      a, 1
        call    .get_address
        ld      [start.vu1], hl
        ld      a, 2
        call    .get_address
        ld      [start.vu2], hl
        ld      a, 3
        call    .get_address
        ld      [start.vu3], hl
        ld      a, 4
        call    .get_address
        ld      [start.vu4], hl
        ld      a, 5
        call    .get_address
        ld      [start.vu5], hl

        ret

        ; DE - screen pos, A - register value
.get_address:
        bit     4, a
        jp      nz, .get_e
        and     0x0E
        ld      h, high .calltab
        ld      l, a
        ld      e, [hl] : inc l
        ld      d, [hl]
        exd
        ret
.get_e:
        ld      hl, .draw_e
        ret

        ; ------------------
        ; drawing routines
        ; DE - dst
.draw_e:
        ld      a, 0b00000000 : ld [bc], a : inc b  ; 18
        ld      a, 0b11111111 : ld [bc], a : inc b  ; 18
        ld      a, 0b11000011 : ld [bc], a : inc b  ; 18
        ld      a, 0b11011111 : ld [bc], a : inc b  ; 18
        ld      a, 0b11000111 : ld [bc], a : inc b  ; 18
        ld      a, 0b11011111 : ld [bc], a : inc b  ; 18
        ld      a, 0b11000011 : ld [bc], a : inc b  ; 18
        ld      a, 0b11111111 : ld [bc], a : ret    ; 24    = 150t per char

.draw_0:
.draw_1:
        dup 7 : ld a, 0x00 : ld [bc], a : inc b : edup ; 18*7
        dup 1 : ld a, 0x00 : ld [bc], a : ret   : edup ; 24*1
.draw_2:
        dup 6 : ld a, 0x00 : ld [bc], a : inc b : edup ; 18*6
        dup 1 : ld a, 0xFF : ld [bc], a : inc b : edup ; 18*1
        dup 1 : ld a, 0xFF : ld [bc], a : ret   : edup ; 24
.draw_3:
        dup 5 : ld a, 0x00 : ld [bc], a : inc b : edup ; 18*5
        dup 2 : ld a, 0xFF : ld [bc], a : inc b : edup ; 18*2
        dup 1 : ld a, 0xFF : ld [bc], a : ret   : edup ; 24
.draw_4:
        dup 4 : ld a, 0x00 : ld [bc], a : inc b : edup ; 18*4
        dup 3 : ld a, 0xFF : ld [bc], a : inc b : edup ; 18*3
        dup 1 : ld a, 0xFF : ld [bc], a : ret   : edup ; 24
.draw_5:
        dup 3 : ld a, 0x00 : ld [bc], a : inc b : edup ; 18*3
        dup 4 : ld a, 0xFF : ld [bc], a : inc b : edup ; 18*4
        dup 1 : ld a, 0xFF : ld [bc], a : ret   : edup ; 24
.draw_6:
        dup 2 : ld a, 0x00 : ld [bc], a : inc b : edup ; 18*2
        dup 5 : ld a, 0xFF : ld [bc], a : inc b : edup ; 18*5
        dup 1 : ld a, 0xFF : ld [bc], a : ret   : edup ; 24
.draw_7:
        dup 1 : ld a, 0x00 : ld [bc], a : inc b : edup ; 18*1
        dup 6 : ld a, 0xFF : ld [bc], a : inc b : edup ; 18*6
        dup 1 : ld a, 0xFF : ld [bc], a : ret   : edup ; 24

        align 256
.calltab:
        dw      .draw_0, .draw_1, .draw_2, .draw_3, .draw_4, .draw_5, .draw_6, .draw_7

        ; player include
        include "player.asm"

        ; music include
music_p0_ch4:
        incbin  "ay_env/ay_env_ch4.bin"
music_p0_ch5:
        incbin  "ay_env/ay_env_ch5.bin"
music_p0_ch6:
        incbin  "ay_env/ay_env_ch6.bin"
music_p0_ch7:
        incbin  "ay_env/ay_env_ch7.bin"
music_p0_ch12:
        incbin  "ay_env/ay_env_ch12.bin"
music_p0_ch13:
        incbin  "ay_env/ay_env_ch13.bin"
music_p0_ch14:
        incbin  "ay_env/ay_env_ch14.bin"
music_p0_ch15:
        incbin  "ay_env/ay_env_ch15.bin"


code_end

        ; -------------------------------------------------
        ; music pages
        page 0
        emptytap "page0.tap"
        org 0xC000
        align   256
        savetap "page0.tap",CODE,"page0",0xC000,$-0xC000


        ; splash screen
        emptytap "splash.tap"
        org  0x4000
splash: 
        block 6144, 0
        block 768,  (0<<3)|(7<<0)
        ;incbin "200a.scr"
        savetap "splash.tap",CODE,"splash",0x4000,$-0x4000

endmodule
; ----------------------------------------------------
total_codelength    equ     code_end-codestart

	display "total:  ", /a, total_codelength, " bytes"

    savesna "moebius.sna", start
    savetap "player.tap",CODE,"moebius",codestart,total_codelength