Famicom 3D System Adapter (HVC-032) Technical Info

Started by 133MHz, May 29, 2010, 09:32:14 am

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133MHz

Does anyone here have the little adapter box that interfaces the Famicom 3D glasses with the console's EXT port and would be willing to take it apart for me? ::)
I need to know what makes it tick internally, for adapting a pair of eDimensional 3D glasses for Famicom use. Either straight up technical documents like schematics or simply high quality pictures of the insides of the adapter will be much appreciated :).

The only bit of info I could find has disappeared from the Internets: :'(

Quote3Dシステムの写真
http://www.ne.jp/asahi/oroti/famicom/ish/ish15.jpg


Thank you!  :D


133MHz

Just what I needed! Thank you! ;D

One little thing though... I can't tell the orientation of the DB-15 connector just by the pictures alone, in order to figure out which signal pins are being used by the 3D adapter. :-[

Also, one thing you might not be very fond of would be to remove the black piece of foam that obstructs the top of a chip, in order to see what kind of chip it is.

UglyJoe

May 29, 2010, 10:17:17 am #3 Last Edit: May 29, 2010, 10:24:50 am by UglyJoe
In IMG_1983.JPG, the adapter has pins 8 - 1 on top (closer to the camera) and 15 - 9 below.  Does that help?  If not, I can poke at it with a multimeter later and get you some specifics.

I have to run, but I'll open the box back up later and see if I can move the foam.

ericj

The chips shows:

SHARP
IX0043AE
8741  Z19




Pinout for the 3 wires from UglyJoe's pic:


Brown - #15 (edit: corrected)
Orange - #1
White - #11

Hope this helps.

Anything else you need while I have this apart?

133MHz

Shouldn't Brown be Pin #15 by the looks of it? Otherwise there wouldn't be +5V power for the adapter.

Apparently the 3D glasses are entirely driven by the OUT1 line, I'm guessing the Sharp IC is some sort of latch (can't seem to find its datasheet), while the other chip is a simple dual op-amp. Might have to trace the schematic in order to really understand what's going on.

Thanks eric ;)

ericj


133MHz

May 29, 2010, 03:26:46 pm #7 Last Edit: May 30, 2010, 07:11:11 pm by 133MHz
I've been researching about how LCD shutter glasses work at an electrical level and I think I've got a pretty solid conjecture on the inner workings of the Famicom 3D System.

Driving the shutters
At first I thought that LCD shutters used simple 0~5V signaling, but actually they must be driven with AC of a few volts and a couple of hundred Hz, feeding DC into them would destroy the liquid crystals. This would explain the seemingly complex circuitry found inside the HVC-032 adapter.

Synchronizing the shutters to the computer
Only one signal wire is used for synchronization in the HVC-032 adapter, which is Pin 11 of the expansion port, also known as OUT1. Not having done any actual measuring on a real Famicom with a 3D enabled game, I presume that the logic state of this signal selects which shutter is enabled at any point in time. If this is correct, the state of OUT1 would be low for an entire television frame, high for the next one, then again low on the next one and so on.

Now I can speculate on how the Nintendo adapter works:

  • The unknown Sharp IC forms an oscillator of sorts, in conjunction with X1, a crystal oscillator (it would be nice to have the value of this crystal ::) ;)). The synchronizing signal from OUT1 enters this chip, presumably to alter the output parameters of the oscillation.


  • The second IC is a dual op-amp, probably used to buffer/amplify/invert the signals for driving the shutters, applying AC into only one of them while leaving the other alone, according to the state of OUT1.



By applying the generated square wave into the left shutter, an inverted version of the same square wave into the right shutter and controlling whether the normal or the inverted version of the generated wave appears at the common terminal between the shutters we can drive the LCD shutters in an alternating fashion. If the normal version is applied to the common terminal, the left shutter would not see any voltage at all (both of its terminals being at the same potential), but the right one will see a rapidly alternating voltage between its terminals (its terminals will always be in contradicting logic states because of the inverted pulses between them). When the inverted version is applied to the common terminal, the roles reverse. This might or might not be the driving scheme used in the HVC-032, but it sure is elegant. ::)

If my hypotheses are correct, I could build my own Famicom 3D System out of my eDimensional glasses, an oscillator and a bunch of logic gates. :D

Quote from: ericj on May 29, 2010, 01:41:45 pm
Looks like the link you posted is just a jpeg of the 3D system.


Damn! I got carried away by the context of where I found it and by "clues" in the file name (sh and 15 as schematic and 15 pin connector).


Post Merge: May 30, 2010, 07:06:08 pm

First tests done on a real Famicom:



Pin 11 seems to be outputting a 30 Hz (or maybe 60 Hz can't be 60, too slow) square wave (haven't been able to measure it but the green LED hooked up to it flickers pretty badly and apparently in sync with the doubled screen elements). I've injected that signal into the v-sync input of the VGA dongle of my eDimensional glasses and while it manages to sync up to the signal, it looks like the glasses are alternating at half of the TV frequency. Guess I'll need to build my own LCD shutter driver or at least work something out with the original VGA dongle.

Also, Falsion seems to pulse the sync line at all times as soon as the game starts up, regardless of whether you're playing on normal or 3D mode, while 3D Hot Rally keeps it low on normal mode and pulses it on 3D mode. Does this mean that the glasses are always working when playing Falsion with them, even in normal play? ???

ericj and/or UglyJoe, I presume you've played these games before. Does the weird thing about Falsion make any sense?

UglyJoe

Quote from: 133MHz on May 29, 2010, 03:26:46 pm
ericj and/or UglyJoe, I presume you've played these games before. Does the weird thing about Falsion make any sense?


The only 3d games I have are JJ and Highway Star.  With both of them, the glasses are only active when the game is in 3d mode.

There's some lag the first time you turn on the 3d, though.  For a fraction of a second (probably less than half a second, but definitely noticeable) you can see the frames toggling on screen before the shutters kick in.  After that first time, though, the shutters kick in as soon as you toggle 3d back on (until you power down the FC).

ericj

You're right, Falsion does cause the shutters to start working as soon as Side A loads. They only stop while loading Side B. Regardless if you hit select to start/stop the 3D effect during gameplay, the shutters continue working. Weird! I never noticed that before.

I tried out a bunch of other 3D system games, like 3D Hot Rally, JJ, and Highway Star, but none of them did this.

Nice observation!  :o

133MHz

Wow, 99% success! :o :D!



So I've built my own shutter driving circuit out of a CD4030 quad XOR chip, and it works like a charm. I can perceive a clear, perfectly stable stereoscopic effect when playing Falsion. The only downside is that I get a pretty annoying "ghosting" effect in high contrast areas due to the LCD shutters not getting dark enough to entirely blank the TV picture, allowing the blocked eye to see part of the wrong image and causing double vision.

When driving the shutters directly from the Famicom's +5V line the ghosting is severe enough to make me see everything double. Tried running the shutters at +10 and +12V and the ghosting is greatly reduced, but still present enough to cause double images. I'm afraid of burning out my glasses by pumping up the voltage too much. I should hook up the original VGA dongle to a 'scope to see what kind of driving voltage it puts out before just ramping it up as high as it'll go.

Ghosting issues aside, I gotta say that the 3D effect in some parts of Falsion is quite effective. Some of the enemies seemed like they were floating in front of the TV screen, and the level bosses use some sort of inverse parallax that looks really cool. On the minus side, I had quite a difficult time focusing my eyes to keep me from seeing doubles of everything. I wonder how much ghosting is present on the original Nintendo glasses, and how much "double vision" you should expect to get from Falsion.

nintendodork

Awesome!  I like your glasses more than Nintendo's. :D
I like to glitch old VHS tapes and turn them into visuals for live music events. Check out what I'm working on - www.instagram.com/tylerisneat

gorgyrip

Sorry for thread resurrection, but can you please post a schematic?

robneal81

Is there a way to either build a custom 3D adapter for the NES, or build a converter that allows the original Famicom 3D adapter to plug into a NES? 

I have an RGB-modded NES and Famicom to NES converters.  I'd love to play the 3D games in RGB on my system, rather than in composite on a Famicom.  Thanks for any help.