Best way for testing a YM2612 emulator?

GreenLine · Post by **GreenLine** » Sun May 15, 2011 5:40 pm

Hi,
I'm writing an emulator for the YM2203 sound chip, which then will evolve into a YM2608/2612 emulator (the YM2203 is the first chip in the OPN family and I need it for adding "1943" to my arcade emulator Tickle).
I've spent the last weeks reading all I could find about this chip and writing small prototypes to test parts of the emulator. The material published in this forum is awesome (thanks Nemesis!) but still leaves me with some big doubts especially in the area of self-feedback and using the output of an operator to phase modulate another one.
It's my understanding that no emulator gets the YM2612 100% right, but if you know one please let me know because the question I'm about to ask is: could you recommend a good hardware for easily test a real YM2612 chip?
The thing I dream about is a YM2612 that interfaces to a PC with a USB device... that would be fantastic! But I think that's just a dream... what do you guys use?

Post by **KanedaFr** » Mon May 16, 2011 7:51 am

GreenLine wrote:The thing I dream about is a YM2612 that interfaces to a PC with a USB device... that would be fantastic! But I think that's just a dream... what do you guys use?

Funny...
I watched Luis presentation at Notacon06 last week end : he made a USB VGM player with a YM2612, a PSG and an Arduino

Look at SigFLUP youtube channel (http://www.youtube.com/user/assemblyassembly) or http://www.dreamincode.net/forums/topic ... t%26%2333/, (audio start part 4 from 08:00)

Since I'm in USB part right now, I think it will be totally possible to make a complex USB device with a Serial part to send data and an Audio In part to play the sound on PC, directly fron the chips output
I really would like to try this one...if I find time and a genny ready to lost its sound hearts

GreenLine · Post by **GreenLine** » Mon May 16, 2011 8:05 pm

Thanks for the link, the presentation was fantastic! I have learned that I definitely have to get a Sega Megadrive... or possibly two.

Then if there is no other choice (i.e. something pre-assembled) it seems that indeed the Arduino-based board is a very fine device.

Post by **KanedaFr** » Mon May 16, 2011 8:36 pm

Arduino isn't 'true' usb
if you want to work on true usb look at thing like Teensy (http://www.pjrc.com/teensy/) or USnooBie (http://frank.circleofcurrent.com/usnoobie/)
They are Arduino compatible. The easiest way to learn stuff...

I swapped to pure C after that, mainly to use USB library LUFA....who has all the code you need for AudioIN (http://www.fourwalledcubicle.com/files/ ... evice.html)

no, no, I'm not telling you "DO IT"

GreenLine · Post by **GreenLine** » Mon May 16, 2011 9:16 pm

I like the Teensy! What holds me back is having the thing shipped all the way to Italy, not much for the extra cost but rather for having to wait for weeks and then risking that the package never arrives (shipping by courier is about $70, too much for me).
The Arduino Uno (http://arduino.cc/en/Main/ArduinoBoardUno) on the other hand is easy to find around here so even if it's more expensive eventually it's going to cost me less and... it's in the LUFA library support list! Still I have to understand, why it's not true USB?

Post by **KanedaFr** » Mon May 16, 2011 9:26 pm

just read the doc about the UNO : you can go ahead !
no a lot of pins, but with IO Expander, it won't be a problem (work like a charm on teensy : I use only 7 pins for cartridge read/write...)

what I call not true usb ? exactly what they wrote on UNO doc :

The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega8U2 programmed as a USB-to-serial converter

no need for this $$^*$ FTDI anymore! so you can write any kind of USB hardware (mass storage, audio,....), not ONLY serial one

HardWareMan · Post by **HardWareMan** » Tue May 17, 2011 3:11 am

USB has long disappointed me. I use only the LAN and the recent WiFi (from the same WizNet). Cross-platform, reliability and speed of data transmission. Here are my priorities. :3 And electrical isolation from PC also has great significance for me.

Post by **KanedaFr** » Tue May 17, 2011 7:38 am

Teensy is full speed...not hi speed.
I discovered this too late.
You'll need to look for the 2 over one the spec about the AVR used.

Else, for speed, it also depends the mode you use (bulk, control, iso...)

for electronic isolation, I don' t know

GreenLine · Post by **GreenLine** » Sun May 22, 2011 8:09 pm

Well... first things first!

Yesterday I bought a Sega Genesis and today I spent quite a bit of time playing Golden Axe and other titles... what a wonderful system it is! There is no way I'm going to open and destroy that thing, so now I'll have to find another copy or some other way to get my hands on a YM2612. Next week I'll probably place the order for the Arduino (or Teensy, I'm still considering it) but whatever the choice it's not going to arrive soon so I still have two or three more weeks to try and get the Yamaha chip. Thanks again for your help, will try to keep you posted on the project progress!

Delek · Post by **Delek** » Mon May 23, 2011 3:34 am

GreenLine wrote:Well... first things first! Yesterday I bought a Sega Genesis and today I spent quite a bit of time playing Golden Axe and other titles... what a wonderful system it is! There is no way I'm going to open and destroy that thing, so now I'll have to find another copy or some other way to get my hands on a YM2612. Next week I'll probably place the order for the Arduino (or Teensy, I'm still considering it) but whatever the choice it's not going to arrive soon so I still have two or three more weeks to try and get the Yamaha chip. Thanks again for your help, will try to keep you posted on the project progress!

Check the mother revision. I mean, are you sure that the Genesis that you bought does not have the VA7 revision of the motherboard?, because there's no YM2612 inside of that mother, only a nasty ASIC based sound generator.

TmEE co.(TM) · Post by **TmEE co.(TM)** » Mon May 23, 2011 6:20 am

The ASIC has YM3438 in it, which fixes quite a few bugs of YM2612, which results in cleaner sound... now if analog sides of those later models wren't so crap...

Delek · Post by **Delek** » Mon May 23, 2011 8:24 am

TmEE co.(TM) wrote:The ASIC has YM3438 in it, which fixes quite a few bugs of YM2612, which results in cleaner sound... now if analog sides of those later models wren't so crap...

Well, if the sound is better or bad compared to the YM2612 is another history (I think that sounds like crap compared to the YM2612). GreenLine is asking for testing a YM2612, so, I think that he needs a Mother revision with the YM2612, indeed.

Also, play around with the ASIC based is a contrary history, the pinout is completely different than the YM2612, and inside that ASIC chip is not only the sound generator, so, for FM SOUND programming tests, it's a waste of time and a lose of focus.

TmEE co.(TM) · Post by **TmEE co.(TM)** » Mon May 23, 2011 11:27 am

You should take some time to read and listen some of the samples you can find here :

http://nfggames.com/forum2/index.php?topic=3719.0

Mega Turrican : http://www.fileden.com/files/2008/4/21/ ... rrican.ogg

There's some comparison recordings of Thunder Force IV aswell, between MD1 VA4, MD2 VA1 and MD2 VA1+CCAM

GreenLine · Post by **GreenLine** » Mon May 23, 2011 11:44 am

Delek wrote:Check the mother revision. I mean, are you sure that the Genesis that you bought does not have the VA7 revision of the motherboard?, because there's no YM2612 inside of that mother, only a nasty ASIC based sound generator.

Ohi Delek... you just sent a shiver down my spine!

I don't know what I have, but I'll be able to post some pictures in a few hours. I can only say that it does seem to sound good to my old ears!

GreenLine · Post by **GreenLine** » Mon May 23, 2011 11:49 am

TmEE co.(TM) wrote:The ASIC has YM3438 in it, which fixes quite a few bugs of YM2612, which results in cleaner sound... now if analog sides of those later models wren't so crap...

Ah... there is hope, thanks for the info!

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Best way for testing a YM2612 emulator?

Best way for testing a YM2612 emulator?

Re: Best way for testing a YM2612 emulator?