*Gasp!* (see page 6 for LOB64 pinout!)

[Rekarp]

I will draw something out later tonight Brian. The LOB64 interface. I like it.

Would be cool if we make this standard for all N64 portables.

The easiest solution is to use two 3.3V regulators. One for the Controller and one for the N64. As for the figuring out what player you are you can just have one port on each portable and then a junction box that connects all 4 together. This way you don't have to worry about which player you are. All that matters is that player 1 is the Master

[Rekarp]

Ok I figured out how to make the LOB64 interface work smoothly.

On the portable side the port has to be the same so each one can function either as a slave or master. This means each portable port has its controller signal on P1. P2, P3, and P4 are hooked up the controller ports on the N64 motherboard.

Now in the Junction box (which will be called the Karp Box ) there are 4 ports on it. Each one represents each player. The Master portable (one with the game in it) must be player 1. Since each portable is sending its controller signal over the P1 line the following happens.

P2 port's P1 line is connected to P1 port's P2 line
P3 port's P1 line is connected to P1 port's P3 line
P4 port's P1 line is connected to P1 port's P4 line

This ensures that any portable using the LOB64 interface will be compatible and makes every portable a Master and Slave portable.

[eagle5953]

Sorry to rain on the parade, but:

When playing N64 in multiplayer, the TV screen typically divides itself into two or four sectors. Each player simply looks as his own section.

If you are simply sending the video signal to other portables, isn't it just going to show the same split-screen view of the master portable? Or did you figure out a way to divide the signal so each split-screen quadrant is displayed on a single screen?

Even if you did successfully divide the screen, won't the resolution still be lower? Suppose it is rendering in 640 by 480 pixels. A four-player split screen means each player has a 320 by 240 piece of the action. By extension, won't the view of each screen look noticeably worse when playing multiplayer? Not that it can be helped, of course.

The idea is still amazing, regardless.

[Rekarp]

Well the idea would be that everyone has there own 5" screen to look at. No looking over shoulders or what not.

[Life of Brian]

You are correct, eagle - the screen will still be split. In my case, I'm just making two portables so the worst that will happen is a screen split in two.

Rekarp - it sounds like it would work, but I don't know if I want an external box if it's just two portables that are connected. However, for three or four player action it would probably be a good idea. Since there would be an external box and we would have the space for it, why not add in some sort of amplifier for the video signal while we're at it? I noticed that when I connect my SNES portables to a TV and have the signal going to the portable's LCD screen at the same time, the LCD screen darkens quite a bit because I'm just splitting the signal two ways with no compensation. I imagine the problem would be worse with four screens feeding off of one signal and traveling along lengthy wires.

[Rekarp]

Thats easy to do. I will draw something up. Well with two players you could get away with a crossover cable. You could make a 4 way cat5 cable but as you said the video would be fairly poor.

[eagle5953]

Not a big deal anyway - we've been dealing with split-screen since day one.

Is it going to be possible for the LOB64 specification to support both Karp-Box 4 player and crossover cable 2 player? It would be best to sort this out before anything is set in solder.

[Life of Brian]

I really think just having a 4 way switch on the portables themselves would be the simplest way to determine what each portable's player number is.

[Rekarp]

Yah the cross over cable would be easy. You just make sure the P2 port's P1 pin is connected to P1 port's P2 pin.

I found a suitable video amp. THS7315DR. It has three separate video drivers so it should work.

[Life of Brian]

Excellent. I've gotten Rekarp involved now

Surely with enough folks thinking it over we can come up with something that works for everyone.

I was thinking about it, and maybe we could design something that works both ways - I'll build a 4 way switch into my portables, but perhaps we can make the Karp-Box as well. I really don't think video signal degradation will be too bad between two screens, but I'm really starting to like the idea of building a signal booster into an external box for 3 or more folks, plus we could include an output to a TV screen as well. That would be an awesome setup at video game conventions - four linked N64 portables with an output to a TV as well so everyone can see the action.

[eagle5953]

Excellent. I've gotten Rekarp involved now

Surely with enough folks thinking it over we can come up with something that works for everyone.

I was thinking about it, and maybe we could design something that works both ways - I'll build a 4 way switch into my portables, but perhaps we can make the Karp-Box as well. I really don't think video signal degradation will be too bad between two screens, but I'm really starting to like the idea of building a signal booster into an external box for 3 or more folks, plus we could include an output to a TV screen as well. That would be an awesome setup at video game conventions - four linked N64 portables with an output to a TV as well so everyone can see the action.

I concur. Now the trick is coming up with an agreeable standard for everyone, as well as a concise document stating explicitly how to make a new portable conform with the LOB64 standard.

Edit:

Ok, so what about this:



Here it is in a much more reasonable size:



All good specifications have a sweet logo. Do you think colors would be better?

[Rekarp]

Only problem I see with using the method Brian (having switches in some and none on others) would be hard to get a set standard down. All N64 devices that use the LOB64 interface should have the same "hardware" in terms of connectivity. This way it avoids confusion.

We can do the switch method on a 4 way Cat 5 cable but each portable will need its own video amp. But confusion may arise if someone doesn't turn there portables switch to the right spot or changes it mid game Also since the LOB64 only supports one video signal you would need a way for the Master system to bypass its own amp as it will be set up for an inputed signal.

Now for only two players you should not need a video amp so a simple crossover cable is needed (using the LOB64 interface).

[Rekarp]

Oh if the karp-box needs output to a TV as well we can just use the THS7374IPW. It has 4 amps

edit take that back. the LT6207 is much better suited for it.

[thewise1]

AAAAAAAAAAAAAAAAAHHHH!!! You guys stole my idea of using an internet jack on the n64!!!

4 Days ago I wired my 2, 3, and 4 player port to a cat5e cable, and got a cat5e jack, I combined all the grounds so I would only need 1 cable for them. I wired the first player separately on a usb port.

I've been working on my own n64, but I haven't made a build thread on it because I don't know when I'll finish it, but I am in the making of one. And I was planning on keeping it a home console at the same time, thus the purpose of the cat5e cable.

[Mario]

Ok I figured out how to make the LOB64 interface work smoothly.

On the portable side the port has to be the same so each one can function either as a slave or master. This means each portable port has its controller signal on P1. P2, P3, and P4 are hooked up the controller ports on the N64 motherboard.

Now in the Junction box (which will be called the Karp Box ) there are 4 ports on it. Each one represents each player. The Master portable (one with the game in it) must be player 1. Since each portable is sending its controller signal over the P1 line the following happens.

P2 port's P1 line is connected to P1 port's P2 line
P3 port's P1 line is connected to P1 port's P3 line
P4 port's P1 line is connected to P1 port's P4 line

This ensures that any portable using the LOB64 interface will be compatible and makes every portable a Master and Slave portable.

That is EXACTLY what I was thinking of. Really creepy.