Compaq

[twist]

I am using a compaq keyboard for my control panel. I'm not sure how to tell the 2 different rows.

Here are some pics:
http://www.f.bz/DCP_0052.JPG
http://www.f.bz/DCP_0053.JPG
http://www.f.bz/DCP_0054.JPG
http://www.f.bz/DCP_0055.JPG


I think that the first 4 and last 4 is the small group, and the 17 in the middle is the big group. See how, on the last picture, the first 4 are not connected, and the last 4 are not connected.

Also, on the other matrix sheet (with the buttons), only those 8 are connected; so I figured that's what it is.

Am I right?

[twist]

Anyone? Any help?  

[JustMichael]

Normally, one sheet of mylar connects to one side of the matrix and the other sheet of mylar connects to the other side of the matrix.
You will need to find where on the mylar the key you want is at and then trace it back to where it connects to the pcb on each sheet of mylar.  Connecting these two points on the pcb will act like that key is being pressed.

If you are going to use this on a 1-player cab with a couple buttons then it will most likely work quite well (and cheap too).

If you are trying to do this for a 2-player Street Fighter style controls then you will in all likelyhood have problems with keys not getting recognized because of too many keys being pressed at once.  An I-PAC would be a far better choice for such a control setup.

[twist]

Normally, one sheet of mylar connects to one side of the matrix and the other sheet of mylar connects to the other side of the matrix.
You will need to find where on the mylar the key you want is at and then trace it back to where it connects to the pcb on each sheet of mylar.

[u_rebelscum]

it's only going to be a 1 player thing, with 6 buttons and 1 joystick. Is that OK?

Most keyboards, even if you get around ghosting, can only handle 4 keys pressed at the same time, even though the original IBM PC keyboard spec called for 6.  With a 4 key limit, you can only get two buttons + a diagonal on the joystick at a time.  With a 6 key limit, you can get a diagonal and 4 buttons at a time (if you can find the correct keys to solder to get around the ghosting problems).

I bet the compaq keyboard has a cheap encoder with a four key limit.  So probably not okay.

[twist]

So I can have 1 joystick, 2 buttons, 1 start button, and a 1player button? Ug...

[The Man]

I have hacked a keyboard, used a Hagstrom encoder, used an I-Pac encoder and hacked a joy pad.

[u_rebelscum]

So I can have 1 joystick, 2 buttons, 1 start button, and a 1player button? Ug...

I wasn't including the start buttons or coin buttons, just the action buttons and the joystick in the limits.  You should not worry about pressing starter start, coin, button 1, and the joystick at the same time.

But the usual maxium limit for a keyboard hack is 1 joystick, 2 action buttons, and (almost) any number of UI buttons (start, coin, pause, escape, tab, etc) .  The reason the number of UI bottons aren't as limited is because you don't need to press them at the same time, like you do need with the joystick and action buttons.  A third action button can be added if it is not used at the same time as the other buttons.  

Of course, it does depend on the keyboard encoder of the keyboard you are hacking.  A high quality encoder could handle 1 joystick and 4 buttons pressed at the same time if hacked correctly.  So these encoders might be okay for a 1 joystick, 6 action button hack, if you don't need to press more than four buttons and the joystick at a diagonal.
This is what people have been trying to say about the problems with keyboard hacking.

[twist]

I'm going to try the keyboard hack, to see if it works. If it doesn't work, I'll eith hack a gamepad or buy an I-PAC.

I also just realized that I can hook more than 1 wire per each of the small pack of wires. Now I can have the buttons I want.

Also, I'm probalbly not going to be pressing more than 2 buttons at a time, so no problem (1 joystick direction, and a button)

[u_rebelscum]

I'm going to try the keyboard hack, to see if it works. If it doesn't work, I'll eith hack a gamepad or buy an I-PAC.

I also just realized that I can hook more than 1 wire per each of the small pack of wires. Now I can have the buttons I want.

Also, I'm probalbly not going to be pressing more than 2 buttons at a time, so no problem (1 joystick direction, and a button)

Remember that a diagonal direction is two button pressed at the same time (left & down for example).  So that's three pressed at the same time.  Of course, you know you cannot press (left & right) or (up & down) at the same time, which means you don't need to worry about them ghosting each other.

But three buttons at a time can work fine with keyboard hack, just watch for ghosting.

[twist]

Thanks URS for the tip.

What stinks about my cab is that I don't have a circular saw to cut the wood easily. I'm doing all of it with a hand saw . I spent almost all day working on it, and didn't get much done. Boo-hoo!

Anyways -- I'm hoping the keyboard hack works for my purposes. This is defienetly comin' along.

There was a Dual Terminal Barrier Strip from RadioShack, but they discontinued it. I either have to buy a 5-position one that is the same, with less positions, or buy some other ones.

[fullerlee]

I hacked a keyboard to give 2 players each with an 8way joystick and 6 buttons. The keyboard is a cheapo $5 form Fry's. I have no problems whatsoever

This is an very good tutorial on avoiding ghosting/blocking:
http://www.mameworld.net/emuadvice/keyhack2.html

I also went the handsaw route. Hard work. Good job I had a rasp to striaghten all those wonky edges.

Good luck.

[twist]

I just realized my computer wouldn't fit in my cabinet with a screen, so I'm either going to put my comp next to or under my cocktail.

Fullerlee...I'm happy to see I'm not the only one who "handsawed." Yeah, it's annoying fixxing all the jagged and rough edges, but I manage; also, I won't notice them after I cover my cab.

Thanks for the support.