Sound issues on Philips NMS 8250 & MegaFlashROM SCC+ SD

Supporter (9)

07-04-2016, 21:50

Hi all,

Apologies if this question has been asked before, I'm new to the whole MSX thing.

I very recently just got my hands on a Philips NMS 8250 and a MegaFlashROM SCC+ SD cart.
When I run games from floppy or cassette tape, the games play perfectly (complete with sounds etc.)
However, when I have the MegaFlashROM SCC+ SD plugged in, I don't seem to be getting any sound of any sort. Everything works OK, but it's all a bit quiet.

I have tried games as ROM files, DSK files and flat files on the SD card.
I have the Philips MSX2 connected to my TV via the SCART socket (producing an RGB output)

I'm not sure if the problem is with the MegaFlashROM cart or the Philips MSX2.
I also have a Toshiba HX-10 MSX which I have not tried this cart in recently, I will give it a try and see if the problem follows the cart.

Any ideas? Is this a common fault?

Thanks
Duncan (woody.cool)

By valkyre

Paladin (704)

07-04-2016, 23:50

Welcome Woody. Quick question, are you involved at the retrocomputermuseum by any chance?

By Louthrax

Prophet (2497)

08-04-2016, 00:21

Welcome Woody, your question is very trendy these days :
nms-8250-alternatives-to-mfrsccsd

To sum up what's on this thread:

This is a common fault, specific to some MSX models (including the NMS 8250). The Toshiba HX-10 should work just fine.
It can be fixed for some ROM games (most Konami's') using the integrated MFRSCC+ PSG (option /P1 when flashing)
A real good fix involves some soldering

By woody.cool

Supporter (9)

08-04-2016, 00:31

valkyre wrote:

Welcome Woody. Quick question, are you involved at the retrocomputermuseum by any chance?

Yes, it's me - we've met a few times at events.
I finally got an MSX2 (as you know I've been looking for one for a while)

Louthrax wrote:

Welcome Woody, your question is very trendy these days :
nms-8250-alternatives-to-mfrsccsd

To sum up what's on this thread:

This is a common fault, specific to some MSX models (including the NMS 8250). The Toshiba HX-10 should work just fine.
It can be fixed for some ROM games (most Konami's') using the integrated MFRSCC+ PSG (option /P1 when flashing)
A real good fix involves some soldering

Awesome, I'll give the /P1 option a try and see if it makes any difference.

By raulsantacruz

Hero (604)

08-04-2016, 00:46

The best solution is to fix 8250. Check Aquijack tutorials (https://www.msx.org/node/44995?page=0) . I fixed the mine and after that I dont have any problem with any cartridge (original scc, fm, music module, etc.)

By Guillian

Prophet (3529)

08-04-2016, 10:29

woody.cool wrote:

Awesome, I'll give the /P1 option a try and see if it makes any difference.

The /P1 option will clone the internal PSG using the one in the cartridge. You can also enable it from recovery menu (holding cursor up while booting) and then selecting C.

By raulsantacruz

Hero (604)

08-04-2016, 11:45

Guillian wrote:

woody.cool wrote:

Awesome, I'll give the /P1 option a try and see if it makes any difference.

The /P1 option will clone the internal PSG using the one in the cartridge. You can also enable it from recovery menu (holding cursor up while booting) and then selecting C.

Hi Guillian!,

One question I have from long time ago about your excellent MFR: why don't you provide an external output sound jack in cartridge? was it not enough room for it? Usually, the msx has a noisy sound output signal. Using the clone PSG in conjuction with this output will produce a very clear sound output and won't be necesseary mixer with internal PSG. Would it be possible to add this output to existing cartridges?

Regards!!

By Guillian

Prophet (3529)

08-04-2016, 12:09

There is no room in the PCB for the jack. But it can be glued to the cartridge case.
It is possible to add the sound output to the cartridge. There is a pad (SND) with the SOUNDIN signal.
So probably connecting the jack to GND and SOUNDIN, and adding a 100nF capacitor is enough.

By valkyre

Paladin (704)

08-04-2016, 16:24

@woody.cool - fantastic that you are now the proud owner of an msx2! Iet us know how you get on with your sound issue. Lots of very nice software now awaits you!!

By mfeingol

Champion (294)

08-04-2016, 19:06

@Guillian:

Is there any way to have the MFRSCC+SD latch PSG cloning mode to the enabled state, so it doesn't have to be enabled on every boot?

By raulsantacruz

Hero (604)

09-04-2016, 01:53

Guillian wrote:

Thanks a lot Guillian!!

I will try to do it soon and let you know the result. Is there a "sure" way to open the cartridge without damage case?

Regards!!