EverDrive Forum

General => Mega EverDrive => Topic started by: munchluxe63 on June 06, 2013, 02:40 AM

Title: No WAV playback with Sega Nomad
Post by: munchluxe63 on June 06, 2013, 02:40 AM
I just got my Mega Everdrive and tested out the WAV playback function; it doesn't work with my Sega Nomad, but it works with my NTSC Model 1 Genesis and certain demo ROMs that appear to have a similar PCM playback feature work.

When the file is opened on the Genesis, it plays as expected, but on the Nomad, only a faint interference noise, no audio.

GYM playback and Genesis games work as expected.

Some more information:

System Type: US NTSC
Firmware Version: 6
OS Version: 8
Assembly Date: 22-05-2013 20:15:8
Title: Re: No WAV playback with Sega Nomad
Post by: KRIKzz on June 06, 2013, 03:52 PM
WAV player use stereo dac inside of cart, but expansion audio lines was removed from nomad
Title: Re: No WAV playback with Sega Nomad
Post by: munchluxe63 on June 07, 2013, 01:10 AM
Oh, I see. Which lines from the cart slot to which pins on the on-board chips need connecting? (I've already connected successfully the SMS mode enable line.)
Title: Re: No WAV playback with Sega Nomad
Post by: Chilly Willy on June 07, 2013, 02:58 AM
It needs more than connecting the cart edge pins - it needs the audio circuitry to mix with the built in audio as well. It's a big mod, but I think Tiido did that... you might check the Nomad mod threads over at Sega16.
Title: Re: No WAV playback with Sega Nomad
Post by: munchluxe63 on June 07, 2013, 05:00 AM
I'm down for it; I have some spare perfboard and probably at least half the components on hand already.

Thank you.

Edit:
I've searched around for a while, but I haven't found a thread.
Title: Re: No WAV playback with Sega Nomad
Post by: Chilly Willy on June 07, 2013, 08:29 AM
It would probably be easier to just PM TmEE.
Title: Re: No WAV playback with Sega Nomad
Post by: munchluxe63 on June 07, 2013, 08:42 AM
Yeah, I gave up and sent him a PM.
Title: Re: No WAV playback with Sega Nomad
Post by: Chilly Willy on June 07, 2013, 10:47 PM
Once you get something worked out, you might consider making a thread on it. I'm sure there are probably others who could benefit from your experience.  :)
Title: Re: No WAV playback with Sega Nomad
Post by: munchluxe63 on June 07, 2013, 11:32 PM
Sure; just have to get my Model 2 back so I can take a look at the circuitry and see how it's mixed.

It would help if I knew which pins the Mega Everdrive's DAC outputs to on the cartridge, though. (I don't even know where the DAC is, although I'm guessing either B1, B2, or B3...)
Title: Re: No WAV playback with Sega Nomad
Post by: villahed94 on June 08, 2013, 09:08 AM
Actually it would need some pin lifting. Sega wired both input pins (32X and SCD) on the 315-5684 to GND, but other than that it's possible.
I would however implement a different circuit as that amplifier chip is really noisy
Title: Re: No WAV playback with Sega Nomad
Post by: munchluxe63 on June 08, 2013, 09:45 AM
Actually it would need some pin lifting. Sega wired both input pins (32X and SCD) on the 315-5684 to GND, but other than that it's possible.
I would however implement a different circuit as that amplifier chip is really noisy

Yeah, I was thinking of just replacing the whole amplifier circuitry anyway; so much needless noise, and it would make this a bit simpler... I spent the past 7 hours or so tracing PCB photographs in GIMP editor and reading block diagrams (for some reason, they're in Greek [and also PAL]) to figure out how the MegaDrive's audio circuitry works. I don't really know how the Mega Everdrive manages stereo WAV audio, but I'm trying to figure it out; I'm guessing it uses two of the CARTEDGE pins, B1 and B3? Once I get my hands on my NTSC Model 2, it would make things a lot easier; maybe someone could explain the process to me?

I dug up this and I guess I'll try to work off of it; sketching things out in Fritzing. I'll have to go out and buy some parts.
http://arcade.ym2149.com/megadrive/mdsndmodv3.jpg
Title: Re: No WAV playback with Sega Nomad
Post by: Chilly Willy on June 09, 2013, 01:36 AM
If you're going to use the CCAM, use the latest. Tiido (TmEE) has a sticky thread at Sega16 for the CCAM:

http://www.sega-16.com/forum/showthread.php?7686-Crystal-Clear-Audio-Mod-for-Sega-Mega-Drive-2-amp-Genesis-2-version-1-0

Actually it would need some pin lifting. Sega wired both input pins (32X and SCD) on the 315-5684 to GND, but other than that it's possible.
I would however implement a different circuit as that amplifier chip is really noisy

I did not know that. That's interesting info. :)

So if you didn't care too much, you COULD just solder a couple lines (and lift the pins). Using something based on the CCAM would sound much better.
Title: Re: No WAV playback with Sega Nomad
Post by: munchluxe63 on June 09, 2013, 09:31 AM
On second thought: since it's a PORTABLE system that I run on a homemade battery pack of 8 NiMH batteries and CCAM will use a bunch of extra power (the Mega Everdrie already lowers my battery life SUBSTANTIALLY; I now need an extra set of batteries), it might not be a great idea. I'm not too bothered with the terrible sound quality, although it would be nice to get the M.ED's PCM working. I'm quite busy, but I'll see if I can do something "cheaper" within the next couple of weeks. (I'm that busy.)
Title: Re: No WAV playback with Sega Nomad
Post by: princemoonrise on November 18, 2014, 06:06 PM
I've just managed to enable Mega Everdrive WAV playback on my Nomad! (along with full 32x audio functionality, SMS FM sound, among other things...)  It is indeed cart port B1 and B3 being not connected, they need to be connected to pins 24 and 10 respectively on Sega IC 315-5684, by way of .022uf capacitor and 47k resistor for each connection, and the surface mount pins do need to be lifted off of the PCB so the solder operation is not for the faint of heart.

ITS GREAT!  Bad audio quality or not, the Nomad makes a great little portable audio player.  Since my Nomad has a replaced screen and runs off of lithium ion rechargable camera batteries, power isn't a problem as it lasts hours on a charge.

Thanks for adding the wav playback feature onto the Mega Everdrive, Krikzz.  I like how it goes down the list of files in sequence so you can make "playlists" by arranging them in different folders.  Hopefully we can get more options in the future for wav playback.  Main inconvenience is having to convert everything to 8 bit 22k, but its well worth it!
Title: Re: No WAV playback with Sega Nomad
Post by: Chilly Willy on November 18, 2014, 08:21 PM
Thanks for posting your findings. :)

And the exact frequency you should use is 45 MHz / 2048 == 21972.65625 Hz.
Title: Re: No WAV playback with Sega Nomad
Post by: princemoonrise on November 21, 2014, 03:49 PM
You're welcome, and thanks for the info.  :)
Does it actually sound better at that frequency?  XD

Here's a cheesy video of when I got the Mega Everdrive WAV playing working:
http://youtu.be/c8RsEo8qCgc

And a better video showing the various mods done to my Nomad after I put it all back together (and used the proper resistors, ehehe).
http://youtu.be/TMMuJZ4rb0I
Title: Re: No WAV playback with Sega Nomad
Post by: Chilly Willy on November 21, 2014, 08:33 PM
You're welcome, and thanks for the info.  :)
Does it actually sound better at that frequency?  XD

You're all of one tenth of one percent off! How can you NOT HEAR THAT?!?!?! ;)   :D

I suppose if you have perfect pitch you probably could, but the average person won't notice a thing. If you resampled to a "standard" frequency of 22050 (half CD rate) you'd be .35% off. Still undetectable by most average humans, but if you have any friends with perfect pitch you could drive them nuts... "Can't you hear that?" "Hear what? Sounds fine to me!" :D
Title: Re: No WAV playback with Sega Nomad
Post by: strider1911 on November 25, 2014, 12:16 AM
May I ask why is there so much interest around WAV playback? Don't you guys have better ways of playing your music?
Title: Re: No WAV playback with Sega Nomad
Post by: Chilly Willy on November 25, 2014, 03:16 AM
May I ask why is there so much interest around WAV playback? Don't you guys have better ways of playing your music?

Better? Yes. Cooler? No.  8)

To be serious, some folks may have the stereo and/or computer in a different room from the game consoles and/or TV. Some family member may have the stereo and/or computer tied up with something else, and you are left with just the Sega. I sometimes have the computer busy doing stuff, and leave my 32X playing MOD, XM, or OGG music in the background.
Title: Re: No WAV playback with Sega Nomad
Post by: princemoonrise on November 25, 2014, 09:18 AM
Most people would just use their phone but over the years I've concluded that using a phone is the worst thing for music playing or gaming, since it kills your battery and slows it down for the communication functions you need it for the most.  That and its a pain to plug it in or remove the card thru a case to update its files.

If I have a game system with me, the one I'd have the easiest time copying music to is the one with the easiest removable media access, and the Mega Everdrive one is so very convenient, except for the need to have to convert the files. 

When I travel to conventions, and retro gaming ones in particular, its fun to pack a portable game system with a video input to test all the crap I end up buying, and for gaming parties and the like.   My Nomad is set up to do this, and having the ability to play a huge game library, and now music when I'm on the road is great!  The li-ion batteries I use are cheap, very portable and last many hours.  I'm all for adding of neat extra features that enhance the usage of our devices, even if they're for old beloved favorites.   Besides, its just freakin' cool.  :D

Still hoping for low bitrate DIVX/XVID playback in the future.  XD
Title: Re: No WAV playback with Sega Nomad
Post by: MockyLock on November 25, 2014, 10:39 AM
Well, i should get my CDX out of its box to play CDs though !
Title: Re: No WAV playback with Sega Nomad
Post by: Chilly Willy on November 25, 2014, 11:34 PM
Still hoping for low bitrate DIVX/XVID playback in the future.  XD

Not gonna happen. MPEG video (any level) is beyond anything lower than the Dreamcast. The N64 MIGHT handle super-low-res, super-low-bitrate xvid with special RSP library, but it's easier and better to just do something like cinepak or RoQ instead.
Title: Re: No WAV playback with Sega Nomad
Post by: Fmamarksman on December 01, 2014, 10:48 PM
Still hoping for low bitrate DIVX/XVID playback in the future.  XD

Not gonna happen. MPEG video (any level) is beyond anything lower than the Dreamcast. The N64 MIGHT handle super-low-res, super-low-bitrate xvid with special RSP library, but it's easier and better to just do something like cinepak or RoQ instead.


Video?

Didn't the Doctor V64 support VCD's?

Not that i've ever even seen a Video Compact Disk. . . But still.
Title: Re: No WAV playback with Sega Nomad
Post by: Chilly Willy on December 01, 2014, 11:48 PM
Still hoping for low bitrate DIVX/XVID playback in the future.  XD

Not gonna happen. MPEG video (any level) is beyond anything lower than the Dreamcast. The N64 MIGHT handle super-low-res, super-low-bitrate xvid with special RSP library, but it's easier and better to just do something like cinepak or RoQ instead.


Video?

Didn't the Doctor V64 support VCD's?

Not that i've ever even seen a Video Compact Disk. . . But still.

Yes, it does... using a Winbond W9925 MPEG-1 A/V Decoder chip.
Title: Re: No WAV playback with Sega Nomad
Post by: Arnold101 on August 20, 2017, 03:27 AM
how i have to convert a wav file to listen on mega edv2?
Title: Re: No WAV playback with Sega Nomad
Post by: FeverDrive on August 20, 2017, 09:11 PM
how i have to convert a wav file to listen on mega edv2?
As far as I know you have to use an audio editing program like Audacity to save your audio file as .WAV 22kHz, 8 bit. Someone correct me if I'm wrong.
Title: Re: No WAV playback with Sega Nomad
Post by: Arnold101 on August 21, 2017, 08:32 PM
thank you