[MSX] MSX-Audio BIOS upgrade for Philips Music Module: update

[FRS]

Hi all,

I updated the documentation for the MSX-Audio BIOS upgrade for Philips 
Music Module on MSXpro ( http://www.msxpro.com )

Fixes:
- The missing conection for the EPROM's A13 pin
- The /CS signals for the EPROM and SRAM were swapped

I also want to clarify some misinterpretations that happened on the 
previous release: The MSX-Audio BIOS I released is generic. This means 
it can be used in *any* Y8950 based device that uses the default MSX 
ports (c0h/c1h and c2h/c3h) and not only on Philips MM as some assumed.

This BIOS is not programmed by me, since it's the original ASCII's BIOS 
that was included on the FS-CA1 ROM. I just splitted it from the rest of 
the ROM (music editor, demos, etc), removed the switch check and fixed a 
little initialization bug.

So, there was two releases on my previous announcement:

1) The generic MSX-Audio BIOS
2) The hardware upgrade kit to support it on the Philips Music Module

Regards,
FRS