BR1GHT PR1MATE
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BOSTON

so i think that at this point, the one thing can could really move forward the "gameboy sound" for both live applications and recording would be the ability to record/mix all four channels separately but simultaneously, ie. have a stereo out each for WAV, NOI, PU1, PU2. The ability to run effects to seperate channels, compress bass, put reverb or delay on leads, actually set levels... all in real-time... would be pretty much amazing.

How possible is this? Would this be something that could be accomplished break-out-box style, having a separate unit with 4 gameboy soundchips slaved to the link port of a master DMG running LSDJ or whatever? or could you just link a master DMG to 4 regular DMGs and cripple/mute the channels that you dont want on each?  i am hoping some of the dev crew can enlighten me!

maybe this is something that has even been done before, that im just not aware of?

thoughts?

egr
Offline
Abandoned on Fire

EDIT:  Re-read your post... that's totally doable with 4 units + 4 carts + a sync box of some kind, I thought you were referring to 4 stereo outs from one unit.

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I'd love to see that happen but I'm guessing it's one of those "if you could do it someone would have by now" things.  There's only stereo out from the sound chip itself so there's nothing to break out, all the sound is already mixed when it gets to the analog stage... right?

Please correct me if I'm wrong 'cause that's one mod that I'd consider worth doing. smile

Last edited by egr (May 7, 2010 4:07 pm)

BR1GHT PR1MATE
Offline
BOSTON

ah, well sort of bad news from NeX:

NeX wrote:

short answer is no, this is impossible. but impossible just means you have to be clever about how you do it wink

the easiest way, is to get 4 gameboys, 4 copies of LSDJ, sync them all together and only program one channel on each gameboy.

there is no such thing as a sound chip in the gameboy, everything, (audio, video etc) is done by the CPU, its a custom chip made for nintendo that is a sort of all in one thing. the only extra chips are some buffers and an amplifier (which doesn't even get used when prosounded)

as for doing something like having two CPUs in one gameboy, i am working on an idea which will be one gameboy with two cartridge slots, that would allow you to run two copies of LSDJ from one gameboy.

to split the actual channels up from one CPU is impossible, and you would have to start from scratch, possibly even go as far to have a custom cartridge with 4 audio processors on there, and all the sound would be made by the cart and the gameboy is nothing more than an interface. but again this would need custom software so you wouldn't be able to use LSDJ or anything like that.

you can do what some people do which is pan one channel to the left, and all the others to the right, it sacrifices stereo sound but gives you two channel audio, which can then be summed again by a mixer to give you stereo after you have done your effects on it etc.

if you were to pan your audio with two gameboys, that would give you all 4 channels on seperate mono lines, then if you mod one gameboy to be small enough to fit inside the first gameboy then you have one gameboy with 4 mono channels out.


also

egr wrote:

EDIT:  Re-read your post... that's totally doable with 4 units + 4 carts + a sync box of some kind, I thought you were referring to 4 stereo outs from one unit.

yeah, that makes sense, but then loses the "live mode" functionality right? ahhh, gameboy dev seems pretty tricky ;P

Last edited by BR1GHT PR1MATE (May 7, 2010 4:48 pm)

nitro2k01
Offline
Sweeeeeeden

You can do it, but remember there will be a small delay between two synced boys, so if you have to effects or something that are supposed to be triggered in the exact same time, they may sound a bit off. (Like the same mlody playing detuned on two channels, a snare playing on two channels and stuff like that)

When recording, what you could do is use a sync device and record one solo'd channel at a time. When playing live, I would recommend splitting the song up between just two boys and using a regular link cable. That gives you a total of 4 mono channels, or 2 mono channels + 1 stereo channel, or however you want to use it. Heck, I've even recorded a single GB and grouped the instruments in two groups, one in the left channel and one in the right, with decent results. It's all about how much effort you want to put into it and what you expect in return.

And by popular demand, no, there's no way to physically break out the individual channels, they're mixed inside the CPU chip and the best you can get is two audio channels per boy.

nordloef
Offline
sweden

Just a thought about this. Would it be possible that all four game boys could use the same cart? Then you'd have the same content on every game boy but individual outputs.

low-gain
Offline
Milwaukee, Wisconsin USA

sync 1 gameboy via midi clock and do recording passes..
if your song doesn't consist of any panning. then you can pan 2 channels out on either L or R and only have to do 2 passes of recording.

shouldn't be too tough.

the mist toggles
Offline
NorthTtrrrway

If you want them all stereo/panning, independent and live, flash the rom with your tracks to 4 carts, mute according to your needs, sync using low-gain's 4-way GB hub and play smile...quite manual, but simple.
edit: not an exact answer to the original question, but a way around it actually

Last edited by the mist toggles (May 7, 2010 5:59 pm)

Subway Sonicbeat
Offline
Brazil

Low-gain gave a better solution. If there is no panning, you can use only 2 gameboys sync'd and pan the channels. So you would have 4 mono channels, specially if you use an rca cable then you can pass the channels thru the effects easily.

Easier and cheaper than 4 gameboys and 4 carts plus the box, unless you already have 4 gbs and carts.

arfink
Offline
Minneapolis

Now, as for multilpe GBs and a single LSDJ cartridge, this isn't feasible since the access lines on the GB cartridge are done in an asynchronous parallel style, meaning you'd inevitably have access conflicts. The only way such a simultaneous access could work is if each GB CPU was programmed to have synchronized sharing of the bus lines, which would be incredibly cumbersome. Low-Gain's solution sounds like it'd be pretty good though, 4 channels with hard panning on 2 gameboys. If you needed further panning you could mix the panning live by hand I suppose.

low-gain
Offline
Milwaukee, Wisconsin USA

Once again... Using Midi Clock is a lot more solid than depending on the sync mode on a DMG. but if you dont have the $$ to fork out for the midi interface then i guess you can't do it that way... But then again, if you had the money to spend on an interface for your puter that has more than 2 inputs, then you probably have the extra $$ to drop on a midi solution for the DMG.

Anyways... Midi clock FTW!

nitro2k01
Offline
Sweeeeeeden

Low-gain: How is DMG-DMG sync any less solid than MIDI if all you want is to keep the boys internally consisent?

scienceguy8
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Carbondale, IL

The answer is to rebuild the GameBoy from the processor up.  Reverse engineer the GameBoy's custom Z80 processor, recreate it in an FPGA, and modify to your hearts content, in this case, assign each sound channel to a different pin.  Of course, this is only an option if you are a glutton for punishment who doesn't mind spending at least 6 months on a project.

arfink
Offline
Minneapolis
low-gain wrote:

if you had the money to spend on an interface for your puter that has more than 2 inputs, then you probably have the extra $$ to drop on a midi solution for the DMG.

I got mine for free... hehehehehe!

Note!
Offline
Brooklon

I always multitrack when recording and never use any sort of sync device other than one chain containing a single note that is 01 in length in all four channels. Poor man's sync. And I never have issues with floating bpm.

That being said, I think Bright Primate is looking for a live solution, right? The best option here would be NeX's original suggestion of two GBs running the same song data, synced and hardpanned. Which is great as long as you don't mind losing your O-commands, of course.

nitro2k01
Offline
Sweeeeeeden
scienceguy8 wrote:

The answer is to rebuild the GameBoy from the processor up.  Reverse engineer the GameBoy's custom Z80 processor, recreate it in an FPGA, and modify to your hearts content, in this case, assign each sound channel to a different pin.  Of course, this is only an option if you are a glutton for punishment who doesn't mind spending at least 6 months on a project.

That exists, but it's not open source. But really, how is an FPGA Gameboy emulator any different than a well written regular emulator?