I just release (about 5 minutes ago) a new version of JEmu2.
As for the MSX part, these are the changes:
* Disk emulation (press F8 to switch disks for multi-disk games, disk writing is not supported)
* Added rudimentary VDP timing
* MSX-Music sound is now also stereo enhanced like SCC/SCC+
* Some little VDP fixes here and there
* Added Snatcher, SD Snatcher, Aleste 2, Aleste Gaiden, Fire Hawk, Undeadline

I'm pretty pleased with the stereo enhancement effect in both SCC and MSX-Music emulation. The already good SD-Snatcher music for example now really sounds better than the real thing IMHO. Maybe something to add in 'blue' and 'open' too?

www.gagaplay.com/jemu2/

NICE!!! is there a way to play that Nemesis2 smooth scroll on a real MSX?

This emu is amzing for being programmed in Java

Thanks :-)
The smooth scroll is done using a specialized driver for Nemesis2. It reads some timer from the MSX' memory and translates it to a pixel offset. Ergo, no, there's no way on a real MSX.

too bad I'm working on something cool for openMSX through a TCL script... but it won't be smooth scrool... I wish.

'Something cool for openMSX through a TCL script'... sounds intrigueing

So how do you like the stereo effect?
(you can disable it in the front-end to hear the difference, especially using headphones)

hint: peek 0xe061



Sounds really nice, I'll bring it up on #openmsx (freenode)

If needed, I could share the code of the modified SCC and 2413.

erikd: that would be cool You'd need to share it under a GPL compatible license, though.

Well, the SCC and 2413 implementations are basically existing implementations translated to java, which I have modified for the stereo effect. The modifications are quite straightforward, really.
I could even just explain what I've done so you can implement it yourself.
In any case, I really have to prepare a new source release anyway, but I see no harm in letting you peek in the source before that, so you can implement same thing yourself?

erikd: please join us on #openMSX on irc.freenode.net and talk to wouter_

Exactly, what are you doing with the mono sound?

eirkd, I'm also interested in hearing what your stereo effect is doing. Sounds interesting.

I'll join the channel soon (I'll have to install some irc client first).

What I'm doing is this:
* I created a new class which has 2 instances of the sound chip emulator (say the SCC), one is panned hard left, the other hard right.
* This new class delegates all register updates to both sound chip emulators.
* One of the sound chips is slightly detuned (this will already make it sound wider). Simply modify one of the chips' clock frequency a bit.
* On the left channel, I halve the output of every odd channel and on the right channel I halve the output of every even channel. So now the channels are panned about and not fully panned but something like 67% (apart from the fact that hard panning doesn't sound very nice, you'd void the effect of detuning).

That's it! It's quite easy to implement, really.

I'm currently playing a bit with delaying the 'halved' channels a bit, which enhances the effect even more. JEmu2 will probably have this in the next version, possibly as an option.

I sounds more spatial... and it sounds better than the ussual mono

Sounds easy indeed. I've used the delay effect quite a lot when mixing 'real' music. The sound gets much fatter if you make a stereo track and delay one of the channels a little bit. I suppose the tuning gives it a bit of a chorus effect.
I'm sure it sounds better than the regular mono sound. blueMSX pans the different audio chips slightly by default (some don't like that but I do) which gives a similar effect when playing music that utilizes different audio chips.

Do you really need to pan the individual channels the way you describe? If not, its easier and more flexible to do a generic stereo expander effect that can be applied to any sound chip.