Mic, 2008

Website: http://jiggawatt.org/muzak/xpmck/
Contact: micol972@gmail.com


What you will need

	Some basic knowledge of MML. For syntax information in english, see these guides:

	http://www.nullsleep.com/treasure/mck_guide/
	http://www.geocities.co.jp/Playtown-Denei/9628/mck/mckc-e.txt (mirror)


	To build the SEGA Master System / Game Gear version of the player you need WLA-DX:

	http://www.villehelin.com/wla.html


	To build the SEGA Genesis version of the player you need the GNU binutils for M68000.
	You can find prebuilt binaries for Windows here.
	The Genesis Z80 driver source builds with WLA-DX, although it isn't necessary to rebuild
	it unless you want to make changes to it.


	To build the Gameboy / Gameboy Color version of the player you need WLA-DX:

	http://www.villehelin.com/wla.html


P(P)MCK commands supported in XPMCK

	&, ^, <, >, [], {}, D, l, o, q, t, v, v-, v+, @, @@, @EN, @EP, @MP, @q, @v


New commands added in XPMCK

	@ADSR, @CS, @FBM, @MOD, @WT, @te, @ve, $, !, AM, FB, M, MF, OP, RS


Commandline options

	-h 		Show help
	-v		Verbose mode
	-w		Treat warnings as errors
	-gbc		Output data suitable for the Gameboy / Gameboy Color
	-gen		Output data suitable for the SEGA Genesis
	-sgg		Output data suitable for the SEGA Game Gear
	-sms		Output data suitable for the SEGA Master System

	If no output filename is specified it will be given the name .asm by
	default.

	If the output filename has a .vgm extension and the target is gen, sms or sgg the
	compiler will generate a .vgm file (uncompressed) instead of an .asm file.



Compiler directives

	These are the XPMCK-specific preprocessor commands available:

		#ELSE			Used together with IFDEF/IFNDEF.

		#ELSIFDEF		Used together with IFDEF/IFNDEF.

		#ENDIF			Used together with IFDEF/IFNDEF.

		#EN-REV num		If num==0 EN macros work similar to other
					MML implementations.
					If num==1 EN is not cumulative, meaning that
					instead of {| 3 4 -7} you write {| 3 7 0}.

		#ERROR "message"	Output an error message and abort compilation.

		#IFDEF, #IFNDEF		Conditional compilation depending on if a
					symbol is defined or not.

					Currently the only symbol defined is the selected
					target, so this check would be valid:

						#IFDEF SMS
							; blah
						#ELSIFDEF SGG
							; blah
						#ENDIF

					The boolean operators & (AND) and | (OR) can be
					used:

						#IFDEF SMS | SGG
							; blah
						#ENDIF

					Note that the boolean operators take opposite
					meanings when IFNDEF is used, i.e.:

						#IFNDEF SMS | SGG	; Means "If not defined SMS or not defined SGG"

		#INCLUDE "filename"	Include the contents of another MML file.

		#NTSC			Inform the compiler that you are going to play the
					song with an update frequency of ~60 Hz. Along with
					the tempo and the note lengths this is used to
					calculate how long each note should be played.

		#PAL			Specify a 50 Hz update frequency. Mutually exclusive
					to #NTSC. Some targets only support 60 Hz playback -
					for these targets this command is ignored.

		#TUNE			Use an alternative frequency table on the SEGA Master
					System to lower the error percentage on higher octaves.

		#WARNING "message"	Output a warning. Aborts compilation if the -w switch has been used.

		#UNIFORM-VOLUME num	Specify a custom maximum volume for all channels.
					The volumes will be scaled to the valid range of
					the target machine.


Syntax

Comment
		Single line comments start with a ; (semi-colon).
		Multiline comments start with /* and end with */


Instrument / algorithm selection
	@num
		Apart from selecting the duty cycle for channels that support it,
		@ also has another purpose in XPMCK. For FM channels it is used to
		select the instrument or algorithm for the channel.
		On the SEGA Master System (YM2413) the valid range depends on the
		channel's current output mode:

			M0 (melody):
				@0  = Custom
				@1  = Violin
				@2  = Guitar
				@3  = Piano
				@4  = Flute
				@5  = Clarinet
				@6  = Oboe
				@7  = Trumpet
				@8  = Organ
				@9  = Horn
				@10 = Synthesizer
				@11 = Harpsichord
				@12 = Vibraphone
				@13 = Synthesizer bass
				@14 = Acoustic bass
				@15 = Electric guitar

			M1 (rhythm):
				@0  = Bass drum
				@1  = Snare drum
				@2  = Hi-hat
				@3  = Top cymbal
				@4  = Tom-tom

		When in rhythm mode, each instrument has a global volume that is shared by
		all channels. This means that a channel modifying the volume for one of the
		rhythm instruments will affect all other channels that are using the same
		instrument.

		On the SEGA Genesis (YM2612) the valid range is 0-7 and selects a range
		of instrument sounds according to the following table:

			@0 = Distortion guitar, high hat chopper bass
			@1 = Harp, PSG-like sound
			@2 = Bass, electric guitar, brass, piano, woods
			@3 = Strings, folk guitar, chimes
			@4 = Flute, bells, chorus, bass drum, snare drum, tom-tom
			@5 = Brass, organ
			@6 = Xylophone, tom-tom, organ, vibraphone, snare drum, bass drum
			@7 = Pipe organ

		The type of sound generated on the SEGA Genesis also depends on the
		current feedback setting (see the FB command).



FM channel ADSR envelope
	@ADSRnum = { attack decay sustain release } or
	           { attack decay1 decay2 sustain release }
		Specify attack rate, decay rate, sustain level and release rate.

		On the SEGA Master System (YM2413) the four-parameter version
		is used and all values have a range of 0-15 (15 being the fastest
		rate / maximum level). Only the custom instrument (@0) uses the
		ADSR parameters, all other instruments have fixed ADSR envelopes.

		On the SEGA Genesis (YM2612) the five-parameter version is used
		and all values have a range of 0-31 (the LSB of sustain and release
		is ignored since they are stored as 4-bit values in the YM2612
		registers). decay1 is the initial fast decay rate, while decay2 is
		the secondary slower decay rate. This command is operator-specific.

		Example:

			#IFDEF GEN
				@ADSR1 = {28 29 4 25 10}
			#ELSIFDEF SMS
				@ADSR1 = {12 13 11 9}
			#ENDIF

			F v10 OP0 ADSR1 c4


Channel separation (pan) macro
	@CSnum = { ... | ...}
		Pans the sound on targets that support it. Valid range is -63-63.
		-63 means full left, 0 means center and 63 means full right.

		The macro is applied to a channel with CSnum and disabled with CSOF.


FM feedback macro
	@FBMnum = { ... | ...}
		Specifies the amount of self-feedback for operator 1. This command
		is used in combination with the @ command on the SEGA Genesis FM
		channels to select the type of sound generated.
		This is the macro version of FB, and allows for rapid changes of
		the feedback value.
		Valid range is 0-7.

		Example:

			@FBM0 = { | 0 0 3 3 7 7}

			E v9 @2 FBM0 c1


Modulator
	@MODnum = { lfo ams fms }
		Specifies a modulator to be used for modulating the amplitude and/or
		frequency of a channel.
		lfo selects the frequency of the modulator LFO. Valid range is 0-7
		(7 being the maximum frequency). Note that the LFO is shared for all channels,
		so issuing a MOD command on one channel will affect all other channels that
		are using a modulator.
		ams selects the amplitude modulation sensitivity. Valid range is 0-7
		(7 being the maximum sensitivity). Amplitude modulation also has to be separately
		enabled with the AM command. This can be done per operator.
		fms selects the frequency modulation sensitivity. Valid range is 0-3
		(3 being the maximum sensitivity).

		This command is currently only supported for the FM channels on the SEGA Genesis.

		The macro is applied to a channel with MODnum and disabled with MODOF.

		Example:

			@MOD0 = {4 2 2}

			E v100 MOD0 OP0 AM1 c1


Waveform definition
	@WTnum = { sample sample sample ... } or
	         { "filename.wav" resample volume }
		Defines a waveform for playback on channels that supports it.
		In the first case the sequence should contain 32 unsigned samples in the
		range 0..MAX-VOLUME.
		In the second case the first value should be a string specifying a
		.wav file to convert. The resample parameter is the frequency to
		resample the .wav file to, and volume specifies the upper limit
		of the volume range the sample data will be scaled to.

		Example:

			@WT0 = {"kickdrum.wav" 8000 15}
			@WT1 = {0 0 0 15 0 0 0 15 0 0 0 15 0 0 0 15 0 0 0 15 0 0 0 15 0 0 0 15 0 0 0 15}

			C v3 WT1 c4


Tone envelope
	@tenum
		Specifies the current tone envelope (frequency sweep).
		Valid range of num is -7-7. Positive numbers make the frequency
		gradually increase, negative numbers make the frequency gradually
		decrease, and zero disables the effect.
		This command is currently only supported when the target is Gameboy /
		Gameboy Color.

		Example:

			A @te2 c1


Volume envelope
	@venum
		Specifies the current volume envelope.
		Valid range of num is -7-7. Positive numbers make the volume
		gradually increase, negative numbers make the volume gradually
		decrease, and zero disables the effect.
		This command is currently only supported when the target is Gameboy /
		Gameboy Color.

		Example:

			A @ve-5 c1


General macro
	$id { ... } 
		Define/use a general macro. These can be used to save typing if a
		lot of smilar patterns are used in a song. Parameters are dereferenced
		with %num% (%1% being the first parameter).

		Example:

			$1 { [%1%]4 %2%.. }

			A $1(c, a)

		The macro invokation on channel A will expand to [c]4 a..


Callback
	!id(frequency)
		Call a function on the host CPU. E.g. if playing a song on the
		SEGA Master System this command would call a function in your
		Z80 code. This can be used to synchronize the visual output
   		of your program with the music.
		The frequency parameter specifies how often the function should be
		called. The available values are:

		0			Never (disable the callback).

		1			Once (called during the next update).

		EVERY-NOTE		Called for every new note that is
					played on the channel(s).

		Example:

			AD !foo(EVERY-NOTE)
			A l16 cdef
			D l32 [g]8

		Here the function foo will be called each time a new note is
		played on channel A or D.


Amplitude modulation enable
	AMnum
		Used for the FM channels on the SEGA Genesis (channels E..J).
		Enable/disable amplitude modulation for the currenly selected operator(s).
		Valid range of num is 0-1 (0=OFF, 1=ON).
		This command is used in conjunction with MOD.


Detune
	Dnum
		For most targets this command works as usual (num specifies number of semitones
		to detune by).
		For the FM channels on the SEGA Genesis (channels E..J) the detune
		command has a more limited range of -3-3. The reason for this is that
		the value is written to the DT1 bits of the selected operator(s).
		Detuning for these channels is also controlled by the MF command.


FM feedback
	FBnum
		Specifies the amount of self-feedback for operator 1. This command
		is used in combination with the @ command on the SEGA Genesis FM
		channels to select the type of sound generated.
		Valid range is 0-7.

		Example:

			E v9 @2 FB6 c1


Output mode
	Mnum
		Specifies the output mode for channels that support more than one
		output mode.
		For the SEGA Master System this command is used for the FM channels
		to select melody or rhythm mode (M0 = melody (default), M1 = rhythm).

		Example:

			E v8 M0 @7 c1
			F v9 M1 @0 [d32r32]16


FM detuning multiplier
	MFnum
		Specifies the amount of detuning together with the D command for the FM
		channels on the SEGA Genesis.
		Valid range is 0-15.
		This command is operator specific.

		Example:

			E OP1 D1 MF7	; Set detune and multiplier for operator 1 on channel E


FM Operator select
	OPnum
		Used for the FM channels on the SEGA Genesis (channels E..J).
		Each channel has four operators, which are set up in various configurations
		depending on the selected algorithm. Some commands are applied on the channel
		while others can be applied per operator. OP selects the operator to apply
		subsequent operator-specific commands to.
		Valid range of num is 0-4. If num==0 all operators are selected.

		Example:

			E OP0 ADSR1		; Set ADSR envelope for all operators on channel E



FM rate scaling
	RSnum
		Used for the FM channels on the SEGA Genesis (channels E..J).
		Specifies the amount with which envelopes scale to the note's pitch,
		creating narrower envelopes as the pitch rises.
		Valid range of num is 0-3 (3 being the maximum amount of scaling).
		The command is operator specific.

		Example:

			E OP1 RS2	; Set rate scaling for operator 1 on channel E


Implementation specific notes

	SEGA Game Gear

		Volume range is 0..15. The lowest playable note is A in octave 2.
		Channels A, B, C are tone channels that output square waves.

		Channel D is used for noise. @0 selects white noise and @1 selects periodic
		noise.

		Limited panning is supported (negative values means full left, zero means center,
		positive values means full right).

		EP and MP can be used together, but they will interfere with eachother.

		For the noise channel the octave setting is irrelevant. The noise generator has
		four different clock settings that is determined by the current note MOD 4. Below
		is a list of what each note corresponds to:

			c, e, g+:	High pitch
			c+, f, a:	Medium pitch
			d, f+, a+:	Low pitch
			d+, g, b:	Pitch determined by channel C.

		By selecting periodic noise generation with pitch determined by channel C it is
		possible to use the noise channel as a kind of extra tone channel.


	SEGA Master System

		Volume range is 0..15.
		The lowest playable note is A in octave 2 for channels A..D, and C in octave 1 for
		channels E..G.

		Channels A, B, C are tone channels that output square waves.

		Channel D is used for noise. @0 selects white noise and @1 selects periodic
		noise. The noise's pitch is determined in the same way as for the SEGA Game Gear.

		Channels E, F, G are FM channels that can output a variety and sounds. Note
		that if you want to play a song using these channels on an actual console
		you will need a modified SMS / Mark-III with an added YM2413 (or a japanese SMS).

		EP and MP can be used together, but they will interfere with eachother.


	SEGA Genesis

		Volume range is 0..15 for channels A..D, and 0..127 for channels E..J.
		The lowest playable note is A in octave 2 for channels A..D, and C in ocatve 1 for
		channels E..J.
		Channels A, B, C are tone channels that output square waves.

		Channel D is used for noise. @0 selects white noise and @1 selects periodic
		noise. The noise's pitch is determined in the same way as for the SEGA Game Gear.

		Channels E, F, G, H, I, J are FM channels that can output a variety and sounds.

		Due to the fact that effect tables are copied to the limited audio RAM, you've got
		harder restrictions on the number of effect macros you can declare. These limits are
		as follows:

			@:	20
			@v:	32
			@EN:	32
			@EP:	16
			@MP:	16
			@ADSR:	16
			@MOD:	10
			@FBM:	7

		EP and MP can be used together, but they will interfere with eachother.
		MP is ignored for channels E..J since MOD can achieve pretty much the same thing.


	Gameboy / Gameboy Color

		Volume range is 0..15 for channels A, B, D and 0..3 for channel C.
		The lowest playable note is C in octave 2.
		Channels A, B are tones channels that output square waves with
		controllable duty cycle (0..3, representing 12.5..75%).

		Channel C is used for Wave playback. You must execute at least one
		WT command on channel C to load a waveform, or the channel will not
		be activated.

		Channel D is used for noise.

		It is preferred to use @ve rather than @v on channels A, B and D.
		The reason for that being that the envelope effect specified by the @ve command is handled
		by the Gameboy hardware, while an @v command causes the player to update the volume bits for
		the selected channel(s) and reset the waveform, which causes distortion.


	General

		Effects are stepped through once per frame.



TODO

Things that would be nice to do, time permitting:

Fix bugs.
Write playback libraries for other platforms.
Implement more effects.
Create a player for Windows.
Optimize the playback libraries.