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< p > < span class = "rvts28" > NES Music Format Spec< / span > < / p >
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< p > ---------------------< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > By: Kevin Horton khorton@iquest.net< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > NOTE:< / p >
< p > -----< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > Remember that I am very willing to add stuff and update this spec. If< / p >
< p > you find a new sound chip or other change let me know and I will get back< / p >
< p > with you. E-mail to the above address. < / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > V1.61 - 06/27/2000 Updated spec a bit< / p >
< p > V1.60 - 06/01/2000 Updated Sunsoft, MMC5, and Namco chip information< / p >
< p > V1.50 - 05/28/2000 Updated FDS, added Sunsoft and Namco chips< / p >
< p > V1.32 - 11/27/1999 Added MMC5 register locations< / p >
< p > V1.30 - 11/14/1999 Added MMC5 audio bit, added some register info< / p >
< p > V1.20 - 09/12/1999 VRC and FDS prelim sound info added< / p >
< p > V1.00 - 05/11/1999 First official NSF specification file< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
< p > < br / > < / p >
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< p > This file encompasses a way to transfer NES music data in a small, easy to< / p >
< p > use format.< / p >
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< p > < br / > < / p >
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< p > The basic idea is one rips the music/sound code from an NES game and prepends< / p >
< p > a small header to the data.< / p >
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< p > < br / > < / p >
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< p > A program of some form (6502/sound emulator) then takes the data and loads< / p >
< p > it into the proper place into the 6502's address space, then inits and plays< / p >
< p > the tune.< / p >
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< p > < br / > < / p >
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< p > Here's an overview of the header:< / p >
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< p > < br / > < / p >
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< p > offset # of bytes Function< / p >
< p > ----------------------------< / p >
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< p > < br / > < / p >
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< p > 0000 5 STRING "NESM",01Ah ; denotes an NES sound format file< / p >
< p > 0005 1 BYTE Version number (currently 01h)< / p >
< p > 0006 1 BYTE Total songs (1=1 song, 2=2 songs, etc)< / p >
< p > 0007 1 BYTE Starting song (1= 1st song, 2=2nd song, etc)< / p >
< p > 0008 2 WORD (lo/hi) load address of data (8000-FFFF)< / p >
< p > 000a 2 WORD (lo/hi) init address of data (8000-FFFF)< / p >
< p > 000c 2 WORD (lo/hi) play address of data (8000-FFFF)< / p >
< p > 000e 32 STRING The name of the song, null terminated< / p >
< p > 002e 32 STRING The artist, if known, null terminated< / p >
< p > 004e 32 STRING The Copyright holder, null terminated< / p >
< p > 006e 2 WORD (lo/hi) speed, in 1/1000000th sec ticks, NTSC (see text)< / p >
< p > 0070 8 BYTE Bankswitch Init Values (see text, and FDS section)< / p >
< p > 0078 2 WORD (lo/hi) speed, in 1/1000000th sec ticks, PAL (see text)< / p >
< p > 007a 1 BYTE PAL/NTSC bits:< / p >
< p > bit 0: if clear, this is an NTSC tune< / p >
< p > bit 0: if set, this is a PAL tune< / p >
< p > bit 1: if set, this is a dual PAL/NTSC tune< / p >
< p > bits 2-7: not used. they *must* be 0< / p >
< p > 007b 1 BYTE Extra Sound Chip Support< / p >
< p > bit 0: if set, this song uses VRCVI< / p >
< p > bit 1: if set, this song uses VRCVII< / p >
< p > bit 2: if set, this song uses FDS Sound< / p >
< p > bit 3: if set, this song uses MMC5 audio< / p >
< p > bit 4: if set, this song uses Namco 106< / p >
< p > bit 5: if set, this song uses Sunsoft FME-07< / p >
< p > bits 6,7: future expansion: they *must* be 0< / p >
< p > 007c 4 ---- 4 extra bytes for expansion (must be 00h)< / p >
< p > 0080 nnn ---- The music program/data follows< / p >
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< p > < br / > < / p >
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< p > This may look somewhat familiar; if so that's because this is somewhat< / p >
< p > sorta of based on the PSID file format for C64 music/sound.< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > Loading a tune into RAM< / p >
< p > -----------------------< / p >
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< p > < br / > < / p >
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< p > If offsets 0070h to 0077h have 00h in them, then bankswitching is *not*< / p >
< p > used. If one or more bytes are something other than 00h then bankswitching< / p >
< p > is used. If bankswitching is used then the load address is still used,< / p >
< p > but you now use (ADDRESS AND 0FFFh) to determine where on the first bank< / p >
< p > to load the data.< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > Each bank is 4K in size, and that means there are 8 of them for the< / p >
< p > entire 08000h-0ffffh range in the 6502's address space. You determine where< / p >
< p > in memory the data goes by setting bytes 070h thru 077h in the file.< / p >
< p > These determine the inital bank values that will be used, and hence where< / p >
< p > the data will be loaded into the address space.< / p >
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< p > < br / > < / p >
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< p > Here's an example:< / p >
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< p > < br / > < / p >
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< p > METROID.NSF will be used for the following explaination.< / p >
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< p > < br / > < / p >
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< p > The file is set up like so: (starting at 070h in the file)< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > 0070: 05 05 05 05 05 05 05 05 - 00 00 00 00 00 00 00 00< / p >
< p > 0080: ... music data goes here...< / p >
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< p > < br / > < / p >
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< p > Since 0070h-0077h are something other than 00h, then we know that this< / p >
< p > tune uses bankswitching. The load address for the data is specified as< / p >
< p > 08000h. We take this AND 0fffh and get 0000h, so we will load data in< / p >
< p > at byte 0 of bank 0, since data is loaded into the banks sequentially< / p >
< p > starting from bank 0 up until the music data is fully loaded.< / p >
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< p > < br / > < / p >
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< p > Metroid has 6 4K banks in it, numbered 0 through 5. The 6502's address< / p >
< p > space has 8 4K bankswitchable blocks on it, starting at 08000h-08fffh,< / p >
< p > 09000h-09fffh, 0a000h-0afffh ... 0f000h-0ffffh. Each one of these is 4K in< / p >
< p > size, and the current bank is controlled by writes to 05ff8h thru 05fffh,< / p >
< p > one byte per bank. So, 05ff8h controls the 08000h-08fffh range, 05ff9h < / p >
< p > controls the 09000h-09fffh range, etc. up to 05fffh which controls the < / p >
< p > 0f000h-0ffffh range. When the song is loaded into RAM, it is loaded into< / p >
< p > the banks and not the 6502's address space. Once this is done, then the< / p >
< p > bank control registers are written to set up the inital bank values.< / p >
< p > To do this, the value at 0070h in the file is written to 05ff8h, 0071h< / p >
< p > is written to 05ff9h, etc. all the way to 0077h is written to 05fffh.< / p >
< p > This is should be done before every call to the init routine.< / p >
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< p > < br / > < / p >
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< p > If the tune was not bankswitched, then it is simply loaded in at the < / p >
< p > specified load address, until EOF< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > Initalizing a tune< / p >
< p > ------------------< / p >
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< p > < br / > < / p >
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< p > This is pretty simple. Load the desired song # into the accumulator,< / p >
< p > minus 1 and set the X register to specify PAL (X=1) or NTSC (X=0).< / p >
< p > If this is a single standard tune (i.e. PAL *or* NTSC but not both)< / p >
< p > then the X register contents should not matter. Once the song # and< / p >
< p > optional PAL/NTSC standard are loaded, simply call the INIT address.< / p >
< p > Once init is done, it should perform an RTS.< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > Playing a tune< / p >
< p > --------------< / p >
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< p > < br / > < / p >
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< p > Once the tune has been initalized, it can now be played. To do this,< / p >
< p > simply call the play address several times a second. How many times< / p >
< p > per second is determined by offsets 006eh and 006fh in the file.< / p >
< p > These bytes denote the speed of playback in 1/1000000ths of a second. < / p >
< p > For the "usual" 60Hz playback rate, set this to 411ah. < / p >
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< p > < br / > < / p >
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< p > To generate a differing playback rate, use this formula:< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > 1000000< / p >
< p > PBRATE= ---------< / p >
< p > speed< / p >
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< p > < br / > < / p >
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< p > Where PBRATE is the value you stick into 006e/006fh in the file, and< / p >
< p > speed is the desired speed in hertz. < / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > "Proper" way to load the tune< / p >
< p > -----------------------------< / p >
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< p > < br / > < / p >
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< p > 1) If the tune is bankswitched, go to #3.< / p >
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< p > < br / > < / p >
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< p > 2) Load the data into the 6502's address space starting at the specified< / p >
< p > load address. Go to #4.< / p >
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< p > < br / > < / p >
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< p > 3) Load the data into a RAM area, starting at (start_address AND 0fffh).< / p >
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< p > < br / > < / p >
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< p > 4) Tune load is done.< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > "Proper" way to init a tune< / p >
< p > ---------------------------< / p >
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< p > < br / > < / p >
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< p > 1) Clear all RAM at 0000h-07ffh.< / p >
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< p > < br / > < / p >
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< p > 2) Clear all RAM at 6000h-7fffh.< / p >
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< p > < br / > < / p >
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< p > 3) Init the sound registers by writing 00h to 04000-0400Fh, 10h to 4010h,< / p >
< p > and 00h to 4011h-4013h.< / p >
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< p > < br / > < / p >
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< p > 4) Set volume register 04015h to 00fh.< / p >
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< p > < br / > < / p >
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< p > 5) If this is a banked tune, load the bank values from the header into< / p >
< p > 5ff8-5fffh.< / p >
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< p > < br / > < / p >
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< p > 6) Set the accumulator and X registers for the desired song.< / p >
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< p > < br / > < / p >
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< p > 7) Call the music init routine.< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > "Proper" way to play a tune< / p >
< p > ---------------------------< / p >
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< p > < br / > < / p >
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< p > 1) Call the play address of the music at periodic intervals determined< / p >
< p > by the speed words. Which word to use is determined by which mode< / p >
< p > you are in- PAL or NTSC.< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > Sound Chip Support< / p >
< p > ------------------< / p >
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< p > < br / > < / p >
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< p > Byte 007bh of the file stores the sound chip flags. If a particular flag< / p >
< p > is set, those sound registers should be enabled. If the flag is clear,< / p >
< p > then those registers should be disabled.< / p >
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< p > < br / > < / p >
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< p > * VRCVI Uses registers 9000-9002, A000-A002, and B000-B002, write only.< / p >
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< p > < br / > < / p >
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< p > Caveats: 1) The above registers are *write only* and must not disrupt music< / p >
< p > code that happens to be stored there.< / p >
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< p > < br / > < / p >
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< p > 2) Major caveat: The A0 and A1 lines are flipped on a few games!!< / p >
< p > If you rip the music and it sounds all funny, flip around < / p >
< p > the xxx1 and xxx2 register pairs. (i.e. 9001 and 9002) 9000< / p >
< p > and 9003 can be left untouched. I decided to do this since it < / p >
< p > would make things easier all around, and this means you only < / p >
< p > will have to change the music code in a very few places (6).< / p >
< p > Esper2 and Madara will need this change, while Castlevania 3j< / p >
< p > will not for instance.< / p >
< p > < / p >
< p > 3) See my VRCVI.TXT doc for a complete register description.< / p >
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< p > < br / > < / p >
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< p > * VRCVII Uses registers 9010 and 9030, write only.< / p >
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< p > < br / > < / p >
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< p > Caveats: 1) Same caveat as #1, above.< / p >
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< p > < br / > < / p >
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< p > 2) See my VRCVII.TXT doc for a complete register description.< / p >
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< p > < br / > < / p >
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< p > * FDS Sound uses registers from 4040 through 4092.< / p >
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< p > < br / > < / p >
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< p > Caveats: 1) 6000-DFFF is assumed to be RAM, since 6000-DFFF is RAM on the< / p >
< p > FDS. E000-FFFF is usually not included in FDS games because< / p >
< p > it is the BIOS ROM. However, it can be used on FDS rips to help< / p >
< p > the ripper (for modified play/init addresses).< / p >
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< p > < br / > < / p >
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< p > 2) Bankswitching operates slightly different on FDS tunes. < / p >
< p > 5FF6 and 5FF7 control the banks 6000-6FFF and 7000-7FFF < / p >
< p > respectively. NSF header offsets 76h and 77h correspond to< / p >
< p > *both* 6000-7FFF *AND* E000-FFFF. Keep this in mind!< / p >
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< p > < br / > < / p >
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< p > * MMC5 Sound Uses registers 5000-5015, write only as well as 5205 and 5206,< / p >
< p > and 5C00-5FF5< / p >
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< p > < br / > < / p >
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< p > Caveats: 1) Generating a proper doc file. Be patient. < / p >
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< p > < br / > < / p >
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< p > 2) 5205 and 5206 are a hardware 8*8 multiplier. The idea being< / p >
< p > you write your two bytes to be multiplied into 5205 and 5206< / p >
< p > and after doing so, you read the result back out. Still working< / p >
< p > on what exactly triggers it (I think a write to either 5205< / p >
< p > or 5206 triggers the multiply).< / p >
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< p > < br / > < / p >
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< p > 3) 5C00-5FF5 should be RAM to emulate EXRAM while in MMC5 mode.< / p >
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< p > < br / > < / p >
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< p > Note: Thanks to Mamiya for the EXRAM info.< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > * Namco 106 Sound Uses registers 4800 and F800. < / p >
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< p > < br / > < / p >
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< p > This works similar to VRC7. 4800 is the "data" port which is< / p >
< p > readable and writable, while F800 is the "address" port and is< / p >
< p > writable only.< / p >
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< p > < br / > < / p >
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< p > The address is 7 bits plus a "mode" bit. Bit 7 controls< / p >
< p > address auto-incrementing. If bit 7 is set, the address will< / p >
< p > auto-increment after a byte of data is read or written from/to< / p >
< p > 4800.< / p >
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< p > < br / > < / p >
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< p > $40 ffffffff f:frequency L< / p >
< p > $42 ffffffff f:frequency M< / p >
< p > $44 ---sssff f:frequency H s:tone length (8-s)*4 in 4bit-samples< / p >
< p > $46 tttttttt t:tone address(4bit-address,$41 means high-4bits of $20)< / p >
< p > $47 -cccvvvv v:linear volume 1+c:number of channels in use($7F only)< / p >
< p > $40-47:ch1 $48-4F:ch2 ... $78-7F:ch8< / p >
< p > ch2-ch8 same to ch1< / p >
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< p > < br / > < / p >
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< p > $00-3F(8ch)...77(1ch) hhhhllll tone data< / p >
< p > h:odd address data(signed 4bit)< / p >
< p > l:even address data(signed 4bit)< / p >
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< p > < br / > < / p >
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< p > real frequency = (f * NES_BASECYCLES) / (40000h * (c+1) * (8-s)*4 * 45)< / p >
< p > NES_BASECYCLES 21477270(Hz)< / p >
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< p > < br / > < / p >
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< p > Note: Very Special thanks to Mamiya for this information!< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > * Sunsoft FME-07 Sound uses registers C000 and E000< / p >
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< p > < br / > < / p >
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< p > This is similar to the common AY 3-8910 sound chip that is< / p >
< p > used on tons of arcade machines, and in the Intellivision.< / p >
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< p > < br / > < / p >
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< p > C000 is the address port< / p >
< p > E000 is the data port< / p >
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< p > < br / > < / p >
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< p > Both are write-only, and behave like the AY 3-8910.< / p >
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< p > < br / > < / p >
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< p > Note: Special thanks to Mamiya for this information as well< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
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< p > Caveats< / p >
< p > -------< / p >
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< p > < br / > < / p >
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< p > 1) The starting song number and maximum song numbers start counting at< / p >
< p > 1, while the init address of the tune starts counting at 0. To< / p >
< p > "fix", simply pass the desired song number minus 1 to the init< / p >
< p > routine.< / p >
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< p > < br / > < / p >
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< p > 2) The NTSC speed word is used *only* for NTSC tunes, or dual PAL/NTSC tunes.< / p >
< p > The PAL speed word is used *only* for PAL tunes, or dual PAL/NTSC tunes.< / p >
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< p > < br / > < / p >
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< p > 3) The length of the text in the name, artist, and copyright fields must < / p >
< p > be 31 characters or less! There has to be at least a single NULL byte< / p >
< p > (00h) after the text, between fields.< / p >
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< p > < br / > < / p >
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< p > 4) If a field is not known (name, artist, copyright) then the field must< / p >
< p > contain the string "< ?> " (without quotes). < / p >
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< p > < br / > < / p >
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< p > 5) There should be 8K of RAM present at 6000-7FFFh. MMC5 tunes need RAM at< / p >
< p > 5C00-5FF7 to emulate its EXRAM. 8000-FFFF Should be read-only (not < / p >
< p > writable) after a tune has loaded. The only time this area should be < / p >
< p > writable is if an FDS tune is being played.< / p >
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< p > < br / > < / p >
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< p > 6) Do not assume the state of *anything* on entry to the init routine< / p >
< p > except A and X. Y can be anything, as can the flags. < / p >
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< p > < br / > < / p >
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< p > 7) Do not assume the state of *anything* on entry to the play routine either.< / p >
< p > Flags, X, A, and Y could be at any state. I've fixed about 10 tunes< / p >
< p > because of this problem and the problem, above.< / p >
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< p > < br / > < / p >
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< p > 8) The stack sits at 1FFh and grows down. Make sure the tune does not< / p >
< p > attempt to use 1F0h-1FFh for variables. (Armed Dragon Villigust did and< / p >
< p > I had to relocate its RAM usage to 2xx)< / p >
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< p > < br / > < / p >
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< p > 9) Variables should sit in the 0000h-07FFh area *only*. If the tune writes< / p >
< p > outside this range, say 1400h this is bad and should be relocated. < / p >
< p > (Terminator 3 did this and I relocated it to 04xx).< / p >
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< p > < br / > < / p >
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< p > That's it!< / p >
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< p > < br / > < / p >
< p > < br / > < / p >
< p > < br / > < / p >
< p > < br / > < / p >
< p class = "rvps2" > < span class = "rvts13" > Created with the Personal Edition of HelpNDoc: < / span > < a class = "rvts14" href = "http://www.helpndoc.com/feature-tour/iphone-website-generation" > Free iPhone documentation generator< / a > < / p >
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