yeah?
then what?

Looks very nice And I am a Music Module fan

Count me in for option 2 or 3

Well it is more obvious what the people want , but sander please be a little more specific.
Can you tell e.g. the question asked by dhau -since that is only as reference to a adaption but not to the pcb in a way that I can use it for a toshiba also. Look if there is a general board you can satisfy more people.
By the way what is the size of the pcb and can you close the housing of philips and /or toshiba module if it is adpated

Quote:

http://www.msx.org/256KB-SampleRAM-and-MSX-Audio-BIOS-on-Toshiba-HX-MU900.newspost4458.html FRS made a schematic for the Toshiba, I believe it suffers from background noise and has to be adjusted by someone with knowledge of analogue audio. I guess owning a Toshiba module helps too.

Don't worry, the following Toshiba upgrades work without any problems and do not produce any background noise:

• 256KB SampleRAM
  
• MSX-Audio BIOS
  

The only upgrade that suffers from background noise is the "audio-in upgrade" (that would allow you to record samples too).

The three upgrades are modular and completely independent. You can just do the SampleRAM and BIOS upgrades and forget the audio-in upgrade. And the better news is: You don't need any extra board for that. The upgrade is very cheap and you only need:

• SIMM30 DRAM module (256KB or 1MB on two or three chips)
  
• SIMM30 socket
  
• PATA-IDE flatcable
  
• 32KB EPROM
  
• 8KB SRAM
  
• 74LS139 or 74HCT139 chip
  
• Do the connections as described.
  

Quote:

Why is there also an 8k SRAM, where is it used for?

As NYYRIKKI correctly answered, the MSX-Audio BIOS uses 4KB of RAM as work-area and this way it doesn't need to allocate any buffer on the precious system memory. This is a main advantage over the MSX-Music BIOS (which itself is a hacked subset of the MSX-Audio BIOS).

On the Music Module upgrade board, I leaved the option for the user to install a 64KB EPROM (instead of the original 32KB needed). When used on this configuration, the board will allow access to the full 8KB of SRAM also. Curiously enough, the standard had space for that, but on the FS-CA1 (the Panasonic MSX-Audio), Panasonic did choose to use the extra 32KB of ROM to install the Synthe Music Editor.

I designed it to support 64KB of EPROM and the full 8KB of SRAM to allow some programmer to use the extra space to code a driver for the Music Module MIDI interface.

The MSX-Audio BIOS do have native MIDI support built-in, but it don't have a driver for the Music Module MIDI interface. This way the compatibility in BASIC with the FS-A1GT MIDI interface could be very possible, only requiring the said driver and the backport of some MML extensions that Panasonic added to the MSX-Music BIOS of the FS-A1GT.

Sadly, RealLife (TM) now got very troublesome and all my MSX projects are halted for good until things get better. So I can't to code such driver and backport the MML extensions.

Sorry, i don't remember, does the original Toshiba audio module have samples in e.g. Moonblaster, i mean playing back samples? I seem to remember that there was no sample memory at all in the Toshiba, maybe that's the first upgrade sd_snatcher is talking about. I don't have schematics of the Toshiba version.

DD, yes, that's the first upgrade. He directly goes for 256kB though (And why not...)

DD: the schematics of the Toshiba version are here: http://msx.retro8bits.com/msxarchives/toshibahx900upgrades.zip

It doesn't uses a print! It uses a SIMM30 module for memory.

@sander: Could you give an answer to my questions although one is answered indirectly via your answer to DD

From the looks of it, this board only fits a Music Module. There's also other wiring needed and I don't think the toshiba will have enough vertical space inside to facilitate the extension board.
Philips:


Toshiba:

the eprom on that thing is a 27c256
i have lots of those here.... (the 27c512 that are in the Toshiba too)

Quote:

the eprom on that thing is a 27c256 i have lots of those here.... (the 27c512 that are in the Toshiba too)

In fact, the better choice is:

- 27C256 for the Toshiba
- 27C512 for the Music Module

Quote:

Does anyone know how stable that latest msx audio bios from FRS is?

Have a look at this thread.

Which one is newer? The beta rom from the frs site, or the link in that old thread (nms 1205 rom)