My Fully modded NES

[ChadTower]

I haven't looked at the pinouts and such yet as this is about #10 in my project queue.  I would imagine, given that there are more signals on the DC controller than on the NES controller port, that I would have to simply terminate the lines that aren't used for the NES emulator.

[spiffyshoes]

Do they out put the same encoding for the controller signals?  I thought they would be different.

[ChadTower]

I would have to think so.  All a controller button is is an open circuit that closes when you press the button.  There is no encoding per se, there is signal or there is not. 

Signal - button pressed
No Signal - button not pressed

The voltage, presumably, comes from the console, either passes the closed circuit and returns to the console (button pressed), or does not come to the controller because the circuit is open (button not pressed).

If these assumptions are mistaken, feel free to correct me.

[spiffyshoes]

Well yeah for each button there is an open and closed signal.  But then the controller chip encodes those signals into a series of timed electrical pulses.  The console then descrambles the encoded signal when it recieves them.

If you had an open and closed signal for each button on the NES controller the NES ports would have to have 9 pins.  But instead they only have 7 and only 5 of those 7 pins are used to transfer the signal.  So basically the signal in encrypted.

Inorder to use the origonal NES ports without modifying the NES controllers at all you would have to have some way of decrypting the signal they send and then re-encrypting it to a dreamcast signal.

[ChadTower]

Hrm... good to know.  I wonder if it would be physically possible to take the relevant parts of the DC controller, alter the PCB/etc, and fit it into an NES controller.

Of course, that would defeat the whole purpose, I guess, of wanting to use nonaltered NES controllers.

[spiffyshoes]

I don't know of any Dreamcast controllers that would be small enough to fit into the NES controller the way the PSX ones I used do.  That doesn't mean they don't exist though.

[ChadTower]

Well, the DC PCBs would need alteration, of course.  You could clearly do away with much of it.  You wouldn't need the triggers, or the analog stick, for instance. 

Of course, now we've gone so far from the original goal, we may as well keep the DC controller ports.  The whole point was to try and be as original as possible without having to use custom controllers.

[spiffyshoes]

Yeah, the only way to get it so you don't have to mod the NES controllers at all is to put a PC inside the NES instead of a DreamCast.

The only advantage to useing a DreamCast instead of a PC is that it is cheaper.

[Stingray]

Yeah, the only way to get it so you don't have to mod the NES controllers at all is to put a PC inside the NES instead of a DreamCast.

The only advantage to useing a DreamCast instead of a PC is that it is cheaper.

Well that and the fact that it's a lot easier to configure.

-S

[mmmPeanutButter]

so you have to flip open the case to put a CD in, or is it not necessary to ever swap CDs?

You can fit every US rom and the emulator on one disk.  NES roms are friggin tiny!

Ok.  First off...  this thing is amazing.  I *will* be building one.

Second.  The quote above says that everyhitng will fit on one cd.  So if I wanted to build one of these and just run the NES then I could build it just as you have?

Everybody seems to be talking abou tmaking a tray loading cdrom drive and this and the other... not necessary if I just want to run NES, right?


Again... amazing.

And the memory card... is that just for saving?  it's not required, right?  What about hiding it in the cart door?

[ChadTower]

Everybody seems to be talking abou tmaking a tray loading cdrom drive and this and the other... not necessary if I just want to run NES, right?

You've got it right.

[Stingray]

And the memory card... is that just for saving?  it's not required, right?  What about hiding it in the cart door?

Memory card is for saving, and yes, there's no reason why you couldn't put it inside the case. That's what I intend to do.

-S

[Shape D.]

I want to try and make one so they are acessable through the hatch on the nes. I havent spent any time working on it though.

[ChadTower]

I would think you're better off making it so that you can swap them out easily.  With 1000+ NES games (counting Famicom) on there, you're going to have a lot of saves.

[mmmPeanutButter]

I would think you're better off making it so that you can swap them out easily.  With 1000+ NES games (counting Famicom) on there, you're going to have a lot of saves.

Maybe I'll stick it out the back.

Or what about this?...

Do you need the memory card in there the whole time? or just to load, and save the game?

Cause you could just open the door on the front, slide in the memory card and then remove it when you don't need it.   That would preserve the look most of the time.

(forgive my potential ignorance, I know nothing about dreamcast)

[Shape D.]

Typically plugging anything into a system while its running does not always work out well.

[ChadTower]

You can hot swap VMUs, can't you?

[mmmPeanutButter]

...and if I'm just using it for saving NES games, do I need the memory card with the display or can I get a generic, non-display version?

[ChadTower]

Does the DC have a nondisplay memory unit?

[mmmPeanutButter]

Does the DC have a nondisplay memory unit?

Take a look here.  I see display ones and non-display ones.

Or maybe I'm just an idiot.

[ChadTower]

I guess they do... damn expensive, though, for an older system.

[Stingray]

Yeah, you can get the ones without the display. They work fine for NES saves. That's what I use. There's a local game shop that has a box of third party DC memory gizmos for something like $2 a pop.

-S

[ChadTower]

I have a buttload of random DC peripherals I picked up when Gamestop cleared them out... don't know if I have generic memory units, though.

[Stingray]

Although the memory display is kind of a neat idea, I've found it to be pretty useless in actual use. I never look at it during the game, because I'm looking at the main display.

-S

[mmmPeanutButter]

Is anybody actually building one?

I'm having trouble with one thing.  I am trying to wire up the reset switch as outlined in the tutorial but I'm not really clear how to wire it to the controller.  Unfortunately the photos in the tutorial are not clear.

I am using the standard controller.

Anybody got any pics or tips for me?

[spiffyshoes]

The Reset switch works just like a regular push button.  You wire one tab to the ground and the other tab to the L and R buttons.  You have to cut away on the circuit board that the Reset button is attached to so that it no longer triggers the imputs on that board and is only wired directly to the Dreamcast controller.

[mmmPeanutButter]

The Reset switch works just like a regular push button.  You wire one tab to the ground and the other tab to the L and R buttons.  You have to cut away on the circuit board that the Reset button is attached to so that it no longer triggers the imputs on that board and is only wired directly to the Dreamcast controller.

I'm not really sure I completely understand what you are talking about...

but my main concern is when I get to the dreamcast controller... the switch is not like a typical button switch, so I am having trouble finding out where the contacts are.  That's why I need some pics.

Fig hasn't been online in a while...  where is that guy??

[babydickonboard]

i'm about to start making one of these.  i just purchased a dreamcast today to use, ive gotten nesterDC burned and working and im about to begin pulling apart my old broken nes and begin fitting in the DC.  I'm going try and  put my VMU inside of the case for sure.  I'm also going to try and make it so that i can swap out the VMU if needed via lifting up the cartrige cover.

The only thing i think ill be dissipointed about is not being able to use the original nes controller ports.  I dont really like the idea of useing atari ports, but if there is no other way {within reason} then it will have to do. i've been think about doing this mod for a while now and i'm stoked that im finnaly starting on it.  i also have tons of friends who want me to do this for them {if it works out}.

[Pik4chu]

Just going to jump in here and say what Ive enoticed about the number of wires discussion.

While the NES controller infact only uses 7 wires (that is, has 7 but uses less) is because it is sending signals from the encoder chip located inside the controller which the NES reads to determine what button was pressed.  The reason that 9 wires are needed is that the chip is REMOVED. And it is NOT comunicating with an NES anymore, rather it has become a controller hack..  Thus one wire for each button on the NES +ground to the corresponding button oin the hacked DC controller located inside the case.  The reason why the NES>Parrallel and NES>USB projects work the way they do is because they simply convert the signal sent by the IC on the NES controller to something readable by your parrallel port (assuming you have correct software/drivers).

So I think people keep crossing these two very different projects together.  The 9 pins are needed for the DC (in NES case)hack because its just like a CP->IPAC. 1 Button = 1 wire+common ground.  So Up, Down, Left, Right, Start, Select, A, B +Ground = 9 connections.

I do agree that its a crime to destroy an Atari controller but thats just me

[Stingray]

I do agree that its a crime to destroy an Atari controller but thats just me

That's why the silicon gods gave us Genesis extension cables.

-S

[shmokes]

That's why the silicon gods gave us Genesis extension cables.

-S

Thou shalt worship no gods before me

[JB]

That's why the silicon gods gave us Genesis extension cables.

-S

Thou shalt worship no gods before me

We aren't. We're worshiping them after you.

[spiffyshoes]

Ok there is a way that you can use the physical NES ports so that it still looks like an NES.

[Stingray]

Clever solution, Spiffyshoes.

And when I said "silicon gods" I was of course referring to Shmokes. Who else could it have been?

-S

[MajorLag]

There might be annother posibility, that doesn't involve modding NES controlers at all.

The NES encoder chip is mearly am 8-bit paralell-to-serial shift register, so it should be possible to wire an NES port to an 8-bit serial-to-paralell shift register (assuming such a thing exists, I don't know for certain) and wire the paralell output of that chip directly onto an internal DC controller board.

This may have noticable lag depending on the chip used, I'm not sure.

[JB]

There might be annother posibility, that doesn't involve modding NES controlers at all.

The NES encoder chip is mearly am 8-bit paralell-to-serial shift register, so it should be possible to wire an NES port to an 8-bit serial-to-paralell shift register (assuming such a thing exists, I don't know for certain) and wire the paralell output of that chip directly onto an internal DC controller board.

This may have noticable lag depending on the chip used, I'm not sure.

Oddly, I was just coming here to link something I stumbled upon that designed a similar device.
http://devcast.dcemulation.com/mods/unicont/nes.php

[Flinkly]

so, what is the update on the chips so that we can use the regular cords and controllers?  i'm looking at this for more of a computer attachement, rather than a dc, but i'm still interested in the encoder/decoder idea.

[ChadTower]

I don't remember anyone saying they were working on it.

[spiffyshoes]

If you want the chips that JB linked to you need to buy the pic and flash it with the program they had on the website yourself.

[Razor]

This is the nuts! Ive been looking for something like this for a while, there was another I saw a year or so ago (i forgot to bookmark) a guy had converted a nes using laptop bits, but this looks like much less hassle, a project for the future methinks