How to build MSX Audio ROM into Music Module?

Door ssfony

Expert (69)

afbeelding van ssfony

23-08-2004, 12:38

Hi all,

I was thinking that it would be cool to have the real MSX Audio ROM in my Music Module. In openmsx i see the 'Panasonic FS-CA1 MSX-Audio' extension, so it seems there is finally some documentation about it.
Who has this documentation, specially about what kind of rom it is?
A copy of the ROM would be nice too.

Maybe someone else allready did this???
It seems like a nice hobby project Smile


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Van karloch

Prophet (2068)

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23-08-2004, 13:20

Yeah, It would be nice so we won't have to use pokes anymore to play Compile games with Music Module. I tried to burn to the Megaflash cartridge, but... ok, no success at all.

It would be cool to change the crappy internal Music Module program for the MSX Audio ROM, but it looks that the ROM inside Music Module can't be more that 32 kB while MSX Audio is 128 kB...

Van Sonic_aka_T

Enlighted (4130)

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23-08-2004, 14:54

I know nothing about hardware, but shouldn't a couple of extra address lines solve that problem?

Van Vincent van Dam

Hero (513)

afbeelding van Vincent van Dam

23-08-2004, 16:00

It's not just adding a few address lines; you need to add the msx audio rom mapper to enable the msx to address the entire 128k Sad

Van jpgrobler

Master (155)

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23-08-2004, 17:10


So lets get the schematic of the mapper in question. Anybody have it?

Van ssfony

Expert (69)

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23-08-2004, 23:28

Yeah! I'm not afraid of a little mapperlogic...
My music module is filled with extra ic's and wires anyway for 256kb ram and a audio1/2 switch. And it would be nice to use a flashrom, coze it's easier programming that. Just rip it of an old PC board Smile

Van BiFi

Enlighted (4348)

afbeelding van BiFi

24-08-2004, 07:30

It seems pc is good for something after all Wink

Van jpgrobler

Master (155)

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24-08-2004, 13:24


Some info from someone that dumped the roms:
Seems the original is a 128k megarom mapped IC. But there is a 32k non mapped) copy of the bios only!

Do we want both the bios an Synth soft or only the bios?
Bios only would be easy to implement - a 32k rom

PS Full download links removed for obvious reasons (

Readme.txt from

Ripped by Fabio R. Schmidlin <>

This file contais the MSX-Audio BIOS of the Panasonic FS-CA1 without the anoying SYNTHE program. It's a 32KB plain ROM, starting at 0000h, so it must be mapped to frames 0 and 1 (0000h-3FFFh and 4000h-7FFFh) of your cartridge.

It doesn't look like so, but the two blocks of 16Kb are not swapped. The cartridge signature 4142h really must be at 4000h.

Readme.txt form

MSX-Audio full ROM with SYNTHE disabled on boot
Modified by Fabio R. Schmidlin <>

This file contais the full ROM of the Panasonic FS-CA1 MSX-Audio, but slightly modified to never boot the anoying SYNTHE Music editor on the boot. You can still use the editor by typing "CALL SYNTHE" on BASIC.

It doesn't look like so, but the of 16Kb are not swapped. The cartridge signature 4142h really must be at 4000h. This is a MegaROM, 16Kb pages, switched at adresses 7FFEH and 7FFFH.

Van SMDNearDark

Master (136)

afbeelding van SMDNearDark

08-02-2005, 13:21

I tried using the 32kb rom.

I burnt it into a 32kb eprom and adapted the music module to put that rom on addresses &H0000 - &H7FFF but it doesn't work so no need to try it.

The initialisation goes fine, the Msx-Audio will be found, but all the compile games hang at bootup so there must be more differences.

Normally the peek(&HFFCA) returns 0 but with the rom in the mmod there will be a RST 30.


Rookie (26)

afbeelding van MTC

13-02-2005, 00:02

There's also a 2 or 4 KB SRAM in the Panasonic MSXAudio. Only thing is I forgot how it works exactly (it's been too long ago). The original ROM also contains ADPCM samples.
Another thing: Once you install the original ROM, you can only add another 128KB sample RAM to the MSXAudio.