Toshiba and Philips Music Modules

By meits

Scribe (6530)

meits's picture

16-01-2012, 19:41

I own a Philips Music module.
One of the first things I did back in the days was to pop out the annoying ROM.
Now, half a man's life later, I ran into a ROM dump of that thing, along with the ROM dump of the Toshiba Music Module.

I put the Philips' ROM on my Megaflashrom and HA, it worked... Still as annoying as always, but still...
Now the rediculous thing is: The Toshiba's ROM worked as well, but the sound was terrible... Just some noise...

Not that I need it fixed, but it surprised me and wonder what causes this...

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By Retrofan

Paragon (1339)

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17-01-2012, 20:55

You don't need the Megaflashrom in order to run the Philips or Toshiba internal ROM. Loadrom or MegaMU will do just fine...

By meits

Scribe (6530)

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17-01-2012, 21:15

That's not the point... The reason why the Toshiba ROM fails to play music on my Philips music module... That's the curious bit...

By Retrofan

Paragon (1339)

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13-05-2012, 16:43

Meits wrote:

That's not the point... The reason why the Toshiba ROM fails to play music on my Philips music module... That's the curious bit...

It's strange indeed, because running the Philips ROM with the Toshiba works fine, just normal sound. (except the sampling and MIDI part doesn't work ofcourse). Had the same problem you described with the Toshiba ROM on the Philips Music Module. Someone can help us out? We are curious...

By RetroTechie

Paragon (1563)

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13-05-2012, 17:03

The Y8950 has 4 general-purpose I/O pins (other than those used for scanning the external keyboard), which IIRC are used for things like muting sound channels, input selection or things like that. And in the Toshiba & Philips modules, in a different way.

Why? Because those pins are not part of any standard, and a Toshiba audio module isn't a Philips Music Module. So setting one of these pins to the same state may cause silence on the one, and noise on the other - or vice versa.

By Manuel

Ascended (19273)

Manuel's picture

13-05-2012, 17:46

You can see what RetroTechie says in this openMSX source code: http://openmsx.svn.sourceforge.net/viewvc/openmsx/openmsx/tr...

By Retrofan

Paragon (1339)

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28-10-2012, 08:53

Meits wrote:

That's not the point... The reason why the Toshiba ROM fails to play music on my Philips music module... That's the curious bit...

Also look over here: http://sourceforge.net/tracker/index.php?func=detail&aid=181...
The only standard mute switch is the one implemented on the HX-MU900. It correctly uses the SP-OFF (bit-3) of the register 7 to mute the sound output.