;
; How to build a .TUN file with a Z80 assembler
; This is designed for z80asm under Linux, but it's all pretty 
; standard stuff.
;
; The actual notes for ITHOTMK come from the .MID file on Arsen Torbarina's 
; Ultimate JSW Fan Page.
;
CROTCHET EQU 10		; Note durations
MINIM    EQU 20
SEMIBR   EQU 40

;
; Tune command bytes
;
REST	EQU	0	
;
; Bytes for the different notes
;
CNAT	EQU	48	;Middle C
CSHARP	EQU	49	;C#
DNAT	EQU	50	;D
DSHARP	EQU	51	;D#
ENAT	EQU	52	;E
FNAT	EQU	53	;F
FSHARP	EQU	54	;F#
GNAT	EQU	55	;G
GSHARP	EQU	56	;G#
ANAT	EQU	57	;A
ASHARP	EQU	58	;A#
BNAT	EQU	59	;B

TUNECALL EQU	254	;Call a sub-tune
TUNERET	EQU	253	;Return from a sub-tune
TUNEHLT	EQU	255	;End of tune

OCTAVE	EQU	12	;Add "OCTAVE" to the notes to move up by 1 octave

	org	0F700h	;Address for in-game tune

	DEFW	channel1	;The 3 channels
	DEFW	channel2
	DEFW	channel3

channel1:
;
; Bars 1-4 repeat as bars 9-12, so they are in a subroutine.
;
	DEFB	TUNECALL
	DEFW	first4
;
; Bars 5-6 are the same as bars 1-2, so they are also in a subroutine.
;
	DEFB	TUNECALL
	DEFW	first2
;
; Bars 7-8.
;
	DEFB    DNAT+OCTAVE, CROTCHET
	DEFB    BNAT, CROTCHET
	DEFB    DNAT+OCTAVE, MINIM
	DEFB	CSHARP+OCTAVE, 	SEMIBR	;Second 4 bars
;
; Bars 9-12 are a repeat of 1-4.
;
	DEFB	TUNECALL
	DEFW	first4		;Third 4 bars
;
; Bars 13-16.
;
        DEFB    FSHARP, CROTCHET
        DEFB    GSHARP, CROTCHET
        DEFB    ASHARP, CROTCHET
        DEFB    BNAT,   CROTCHET
        DEFB    CSHARP+OCTAVE, CROTCHET
        DEFB    ASHARP, CROTCHET
        DEFB    CSHARP+OCTAVE, CROTCHET
	DEFB	FSHARP+OCTAVE, CROTCHET
	DEFB	CSHARP+OCTAVE, CROTCHET
	DEFB	ASHARP, CROTCHET
	DEFB	FSHARP, CROTCHET
	DEFB	ASHARP, CROTCHET
	DEFB	CSHARP+OCTAVE, SEMIBR
	DEFB	TUNEHLT
;
; Subroutine for the first 2 bars
;
first4:
	DEFB	TUNECALL
	DEFW	first2
	DEFB	DNAT+OCTAVE, CROTCHET
	DEFB	BNAT, CROTCHET
	DEFB	DNAT+OCTAVE, MINIM
	DEFB	CSHARP+OCTAVE, CROTCHET
	DEFB	ASHARP, CROTCHET
	DEFB	CSHARP+OCTAVE, MINIM
	DEFB	TUNERET
;
first2:
	DEFB	FSHARP, CROTCHET
	DEFB	GSHARP, CROTCHET
	DEFB	ASHARP, CROTCHET
	DEFB	BNAT,   CROTCHET
	DEFB	CSHARP+OCTAVE, CROTCHET
	DEFB	ASHARP, CROTCHET
	DEFB	CSHARP+OCTAVE, MINIM
	DEFB	TUNERET
channel2:
	defb	TUNEHLT
channel3:
	defb	TUNEHLT