OpenMSX and ePSG or dual/double PSG | MSX Resource Center (Page 3/4)

Paladin (887)

13-03-2022, 02:31

Is MegaFlashROM_SCC+_SD the only extension that support dual-PSG in the vanilla OpenMSX version?

There is dual MSX-Audio (audio and audio2) but I don't found same thing for PSG, it's a pity.
There doesn't seem to be an extension to emulate the Darky (?) cartridge either.

I know we can modify the configuration of a MSX computer to add manually a second PSG, but as part of my MSXgl library, I would like the user to be able to test the 6-channel WYZ player without having to tweak the OpenMSX config files.

Par ro

Scribe (4913)

13-03-2022, 09:57

the beauty of OPEN_anything is that any one can either contribute or shift stuff, and the best part is the sharing of that.
So, yeah make a config and have share it so the openMSX team can add it to the "default" lib

Personally, I'd love to see Darky running in openMSX and get more traction going.

Par aoineko

Paladin (887)

13-03-2022, 10:55

I'm contributing to the "OPEN_anything" world by doing what I'm best at: creating an open source MSX game library in C.
It already takes up most of my free time and I'd rather stay focused on this task than spread myself thin in all directions.
I'm pointing out what I think is a lack in OpenMSX; free to people who are competent / interested, to fill it or not.

Par Manuel

Ascended (19299)

13-03-2022, 13:55

Emulation of something like Darky is non-trivial, as it not only contains a dual PSG, but also effect processors.

As on a real MSX, besides Darky, there aren't that any options for a dual PSG, other than MegaFlashROM SCC+ SD. Carnivore 2 has it as well in the latest firmware, but I don't think that part is available/configurable yet in the emulated version.

Par Parn

Paladin (833)

14-03-2022, 02:42

With the Makoto (YM2608) and Neotron (YM2610B) sound extensions you have three more PSG channels, but I have no idea if those are mapped in the same port as the extra PSG in the MFRSCC+SD. Oh, and GR8NET can also be configured to have an extra PSG as well.

Par Grauw

Ascended (10706)

14-03-2022, 03:30

Those OPNA/B PSGs are not mapped to the same secondary PSG I/O port, and also they don’t have the right clock frequency to sound in tune with the internal PSG… (4 MHz instead of 3.58 MHz)

Par Parn

Paladin (833)

14-03-2022, 09:42

In other words, if I wanted to support those as a secondary PSG, I would have to detect them, assign the right ports and use a different frequency table, right? Seems quite a bit of effort. :-/

Par Briqunullus

Hero (642)

14-03-2022, 11:46

aoineko wrote:

I know we can modify the configuration of a MSX computer to add manually a second PSG, but as part of my MSXgl library, I would like the user to be able to test the 6-channel WYZ player without having to tweak the OpenMSX config files.

On the first page in this thread I have posted a xml file for a secondary psg extension. Copy it to your openMSX files and it will list under available extensions in the emulator. Maybe it can be included with openMSX one day.

Par aoineko

Paladin (887)

14-03-2022, 12:57

In the context of the MSXgl library, which I want to be "ready to use", I prefer to limit myself to the features of the emulators' vanilla version, rather than asking the users to go and configure them to make it work. The goal is they can focus on game/program creation.

To come back to the topic, there is no real problem here since the MegaFlashROM_SCC+_SD extension allows to launch the emulator with a second PSG and thus to test my 6 channels WYZ sample program with vanilla OpenMSX. I was just surprised that we have to use such a complex extension to emulate a second PSG, but now I understand better.

Par Parn

Paladin (833)

14-03-2022, 18:05

Indeed OpenMSX favors emulating the real hardware as closely as possible, so it tends not to offer such solutions that don't correspond to real hardware. Maybe the "boosted" configurations could be upgraded to include the second PSG. Meanwhile, other emulators like WebMSX that focus on ease of use have a toggle switch so you can turn a second PSG on and off at will. I don't know if that's useful to you, though. I personally like WebMSX but prefer using OpenMSX almost always.