Chip synths

[cheater]

Well, since the MB is getting a lot of oldschool-style chip synths (thanks a lot Thorsten and the rest!)... why not follow the punch?

I personally know I'd love to see exploited.. the Sega Genesis sound system. As far as I know there are two chips, one is a Yamaha 4-op FM chip, and the other one is wavetable or something similar (might be wrong here  ??? )

Having been exposed to a lot of sounds made by this setup ( ;) ) I must confess I've heard sounds on the Genesis I wouldn't imagine on any (other) synth. It has a character of its own, and is a great thing. I know there's already a Yamaha FM thing going on - but it's still a completely different sound. Besides, there are two chips in it :)

Of course, there are other obvious suggestions: a Gameboy Classic chip synth...

Or perhaps a mobile phone chip? I'd suggest the Nokia 3310. At least in Europe it's so damn popular you could easily get them (broken) for free, to salvage :) Besides, it has that gimmick-ish bleep-blep-ping sound! I just love it 8)

Perhaps all those new projects could soon become a featureful workshop for the DIY synth player :)

I feel the sounds those things can produce could be extremely, extremely inspiring.

[cheater]

Bump ;)

Come on guys, do you think this is an interesting idea worth pursuit?

A question to Thorsten: Once the MB FM is done, do you think it'd be hard to adapt it to a different Yamaha FM chip (e.g. Sega Genesis chip or an arcade chip)? Judging from what I've read, they all seem to have very similar features... the question is whether the code reflects that :)

[DrBunsen]

AS far as the Gameboy sound goes, you might want to check out nanoloop.de and search for Little Sound DJ (LSDJ).  They are both sequencer carts for original Gameboys.  Both can do MIDI sync.  

Nanoloop is a commercial product, but the LSDJ site has instructions for making your own cart and MIDI cable, as well as selling premade carts.  For general Gameboy hacking info, try devrs.org .  And if you're into chipmusic, have a look at micromusic.net .

As the Gameboy side of things is pretty well taken care of by these projects, TK going on his previous posts would probably not want to put any time into a MIOS Gameboy.  Correct me if I'm wrong here, Thorsten!  

On the other hand, it did occur to me that a Gameboy would make a nice display and controller add-on to a MIOS machine...

;D

[cheater]

MIOS gameboy... nah :) He didn't make a MIOS C64 either :)

I admit, the cart synths may be there... but we all know how ultimately better the MB SID is from the C64-driven SID synths :) Or other SID synths for that matter :P

I'm still wondering about the possible cross-compatibility between Yamaha chips...

On a side note: the yamaha chips had very wide applications :) e.g. the chip in my DX11 was primarily an arcade sound chip :)

The sound is great, and so is the synth 8) Shows how you can take a toy and make a professional tool out of it... in chip music, that is :)

Thanks for the links, I'll check them out

----

More generally, there's a certain set of features that all synths will use (envelopes, LFOs, WTs, level control, mod matrix, etc)

Idea: separate this from the SID/FM synth into an entity of its own, so building subsequent synths is much easier.

edit: adding stuff as I think of it. Nothing like slow thinking on Jan1 :)

[TK.]

Hi,

the MBFM application is implemented in a way which allows to reuse most parts of it for other synths. The low-level layer which accesses the OPL3 registers is strictly seperated from the voice/instrument layer, which allocates and initializes the voices. Parameters are listed in a table which can be extented if required. The number of voices/instruments can be changed with single constants (but the RAM allocation has to be adapted by hand). LFOs/EGs/Wavetable, etc (-> the sound engine) is seperated. The menu interface handler is very flexible and can also be adapted very easily by people who have studied the code intensively --- and thats the point. Plug&Play is not possible, it always requires some programming knowledge to adapt the application to a new synth chip. Don't think that I will do this for you, I've already a lot of fun with the OPL3 - the possibilities will keep me busy for the next months :)

For the case that somebody wants to implement a synth based on another chip, here a short checklist for things which have to be taken into account:

• datasheet free available? (it's not allowed to publish code which is based on NDA informations)
  
• availability of synthchip? (think about the case that you destroy one or two chips during the first experiments)
  
• has the PIC enough memory to store all the sound parameters? (if not, you must plan with much more expensive microcontrollers --- and you have to develop a new operating system)
  
• is it worth the effort? (or can a virtual sw synth do the same?)
  

Best Regards, Thorsten.

[cheater]

Thanks :) it seems like MIOS is really well written.

Never wanted you to do anything for me, Thorsten :) I perfectly know the value of time.

Oh well, I've always wanted to learn assembler (I know I'll have a lot of use for it once I start my own research) :) guess now is the time - too bad I don't *have* the time ;) I'll probably read up in the summer. Until then it's multi-variable caluculus and abstract algebra for me :o

Regarding the microcontroller specs thing.. wonder how long until there's a more powerful PIC :) Oh well, you can always just use more cores. :P Thorsten: I read somewhere you were foraying into the world of grown-up microcontrollers. Any Midibox-related plans? :)

On a side note: how can someone check if I used NDA material to write code? How do they know I hadn't just reverse-engineered the specs? Also, wasn't it true that reverse engineering for self-educational purposes was allowed? Or maybe I'm just stupid :P

[smashtv]

On a side note: how can someone check if I used NDA material to write code? How do they know I hadn't just reverse-engineered the specs?

Here is the way this plays out in the US:  The IP rights holder brings an infringement case against the people/company in question, and presents evidence showing their code or specific features within the product in question.  Then it's up to the defendant to prove that it was a "clean room" process, meaning that no confidential or trade-secret type information was derived from any other source than the original product itslef.  A clean reverse creates documentation at every step so it's easy to prove.  Do a search for the history of PC BIOS for more info....

Also, wasn't it true that reverse engineering for self-educational purposes was allowed? Or maybe I'm just stupid :P

Absolutely!

But if you sell (or with the newer laws simply re-distribute) anything but a proven clean reverse then you are breaking the law.  

Again this is only a US perspective, in other countries the laws are different.

How does this relate to the MIDIbox?

Some of the old school sound chips documentation is considered a trade secret or protected by an NDA or confidential.  The only smart reason for this is to control development insuring only approved developers are using these chips.

So even though we can get all needed dev info and datasheets, we can't legally re-distribute any of that info so proper documentation of a new use of the chip would be impossible.

There are enough cool sound chips out there with public docs to keep us all busy for a looooong time......but we should avoid the ones that don't in case someone wants to make a stink in the future.

Best!

Smash

[cheater]

Some of the old school sound chips documentation is considered a trade secret or protected by an NDA or confidential.  

Perhaps we could write letters, requests? I somehow feel Nintendo wouldn't mind the publicity of a Gameboy synth...

There are enough cool sound chips out there with public docs to keep us all busy for a looooong time......but we should avoid the ones that don't in case someone wants to make a stink in the future.

Can you name some interesting ones? :)

Also: are they easily found and/or affordable?

Also: is the sound *just that sound* or are those just readily-made synth chips?