HW_Expansion_Data = $A10007
HW_Port_1_Control = $A10009
HW_Port_2_Control = $A1000B
HW_Expansion_Control =  $A1000D
Z80_RAM =       $A00000 ; start of Z80 RAM
Z80_RAM_end =       $A02000 ; end of non-reserved Z80 RAM
Z80_bus_request =   $A11100
Z80_reset =     $A11200


        lea HW_Port_1_Control,a1
        move.b  -8(a1),d0
        andi.b  #$F,d0
        beq.s   .SkipSecurity
        move.l  Console.w,$A14000-HW_Port_1_Control(a1)

    ; put z80 reset program in
.SkipSecurity   lea $2D0.w,a4
        lea Z80_RAM,a0
        move.w  #$100,Z80_bus_request-HW_Port_1_Control(a1)
        move.w  #$100,Z80_reset-HW_Port_1_Control(a1)
.waitz80    btst    #0,Z80_bus_request-HW_Port_1_Control(a1)
        bne.s   .waitz80

        moveq   #$26-1,d2
.loadz80    move.b  (a4)+,(a0)+
        dbf d2,.loadz80

    ; reset PSG
        add.w   #12,a4          ; advance by 12 bytes
    rept 4
        move.b  (a4)+,$C00011       ; send command
    endr
        move.w  #0,Z80_reset-HW_Port_1_Control(a1)
    rept 4
        nop
    endr
        move.w  #$100,Z80_reset-HW_Port_1_Control(a1)
        move.w  #0,Z80_bus_request-HW_Port_1_Control(a1)



    [ some code here ]

SndDrvInit:
        nop
        move.w  #$100,Z80_bus_request
        move.w  #$100,Z80_reset     ; release Z80 reset

        lea kos_z80,a0
        lea Z80_RAM,a1
        jsr KosDec.w

        move.b  #$11,Z80_RAM+$1C03
        move.b  #$F2,Z80_RAM+$106C
        move.w  #0,Z80_reset        ; reset Z80
        nop
        nop
        nop
        nop
        move.w  #$100,Z80_reset     ; release reset
        move.w  #0,Z80_bus_request  ; start the Z80
        rts