Top secrets sources NedoPC ngs

        CPU     Z80UNDOC
        RELAXED ON

        include "ports.inc"


halfper equ     3000000

        org     0x4000


        ld      a,M_NOROM+C_24MHZ
        out     (GSCFG0),a

        im      0

        ld      hl,0x28
        ld      (hl),0xc3
        inc     l
        ld      (hl),cnt1&255
        inc     l
        ld      (hl),cnt1/256

        ld      l,0x30
        ld      (hl),0xc3
        inc     l
        ld      (hl),cnt2&255
        inc     l
        ld      (hl),cnt2/256

        ld      a,0x7F
        out     (INTENA),a
        out     (INTREQ),a

        ld      a,M_SETNCLR+M_MP3_DMA_INT
        out     (INTENA),a
        out     (INTREQ),a
        ei
        jr      $
cnt1
        ld      a,M_MP3_DMA_INT
        out     (INTENA),a

        ld      a,M_SETNCLR+M_SD_DMA_INT
        out     (INTENA),a
        out     (INTREQ),a
        ei
        jr      $
cnt2
        ld      a,M_SD_DMA_INT
        out     (INTENA),a

        ld      a,M_SETNCLR+M_TIMER_INT
        out     (INTENA),a
        ld      a,0x7F
        out     (INTREQ),a


        ld      l,0x38
        ld      (hl),0xc3
        inc     l
        ld      (hl),intt&255
        inc     l
        ld      (hl),intt/256


        ld      hl,0
        ld      (counter),hl
        xor     a
        ld      (counter+2),a
        ld      (mode),a


        ei


loop
        ld      hl,65535
        ld      d,h
        ld      e,l
wai
        ld      b,15
        djnz    $
        add     hl,de
        jp      c,wai

        ld      a,(mode)
        inc     a
        and     7
        ld      (mode),a
        out     (TIM_FRQ),a

        jr      loop


intt
        exx
        ex      af,af'

        ld      a,(mode)
        add     a,a
        add     a,a
        add     a,tbladd&255
        ld      e,a
        adc     a,tbladd/256
        sub     e
        ld      d,a

        ld      hl,counter

        ld      a,(de)
        add     a,(hl)
        ld      (hl),a
        inc     de
        inc     hl
        ld      a,(de)
        adc     a,(hl)
        ld      (hl),a
        inc     de
        inc     hl
        ld      a,(de)
        adc     a,(hl)
        ld      (hl),a

        dec     hl
        dec     hl

        ld      a,(hl)
        sub     halfper&255
        ld      c,a
        inc     hl
        ld      a,(hl)
        sbc     a,(halfper>>8)&255
        ld      b,a
        inc     hl
        ld      a,(hl)
        sbc     a,(halfper>>16)&255

        jp      c,eintt

        ld      (hl),a
        dec     hl
        ld      (hl),b
        dec     hl
        ld      (hl),c

        ld      a,0
        inc     a
        ld      ($-2),a
        out     (LEDCTR),a

eintt
        exx
        ex      af,af'
        ei
        ret

tbladd
        dw      640,0
        dw      1280,0
        dw      2560,0
        dw      5120,0
        dw      10240,0
        dw      40960,0
        dw      32768,2
        dw      0,10


counter equ     $

mode    equ     counter+3