Wiring - would this work?

[eds1275]

It works 100% in my head but thought I would ask here as I have no way of testing.

My friend has a 2 headed arcade machine!

Dunno what kind it used to be, but this is the route he is going. He has 2 mame machines in there, one for the left and the other for the right.

He wants to be able to play 2 player games as well, with each player getting their own screen. So I came up with the following:
Video splitter from left side to a video select switch on the right - or possibly just use a different input if they are TVs, I don't remember at this point. So that covers the video control - easy enough.

For controls, I suggested him getting a 2-player encoder for the left side, and wiring everything up to it - both sets of controls. And then on the ground coming from the right a select switch that chooses where the ground goes - to the two player encoder on the left or to a one player encoder on the right that also has the button connections going to it.

[PL1]

The video splitter/KVM switch sounds good.

A 2-output video card on computer 1 would eliminate the need for the splitter.

The only problem is your plan to put a switch controlling which encoder's ground is connected. (red box in diagram)

The problem is that ground is ground and when the pushbutton is pressed, both encoders will output a keystroke since both are grounded to each other via their USB/PS2 connection.

I confirmed this by shorting an encoder input to a grounded metal piece on a power strip -- it worked just as well as shorting it to the encoder's ground terminal.

To be able to switch between completely-independent operation and 2-players-on-1-computer use a KVM switch to connect the P2 screen and P2 encoder to computer 2 when switched one way and computer 1 when switched the other way.

If you use keyboard-type encoders, you can have position 2's encoder set to MAME P2 settings and change computer 2's MAME P1 controls to use P2 defaults and clear the P2 settings.

If you use 2 gamepad encoders, the computers should be able to handle P2 encoder being "plugged in" and "unplugged" via the KVM without causing problems and without remapping MAME defaults.


Scott

[kahlid74]

Don't forget Nephasth just finished his Two-Headed beast project as well.  Might be some golden nuggets in that thread as well.

http://forum.arcadecontrols.com/index.php/topic,108719.msg1154107.html#msg1154107