Keyboard vs. KB encoder

[Stingray]

I was recently given an old control panel from a Cyberball 2072 cabinet. I got what I considered at the time to be a crazy idea, and wired the thing into an old keyboard that I happened to have so I could use it with MAME on my computer. Little did I realize at the time that there are plenty of folks out there with the same crazy idea! So anyway, I've got the CP close to finished, and then I discovered this site! Too bad I didn't know about it last week.

In any case, I had never even heard the term keyboard encoder before I discovered this site. I was just wondering what the advantages using an encoder have over just wiring the controls directly into a keyboard. Anyone care to enlighten me?

By the way, I'm just curious, I have no intention of ripping this thing apart and starting over. This was just a little project that I did for kicks using some spare bits that I had around the house.

Thanks
-S

[Jakobud]

The biggest advantages are,

1. super easy to wire
2. no matrix = no ghosting
3. no limitations that keyboard hardware have

Just go the encoder route and trust us

[GamingGreg]

Mostly it deals with "keyboard ghosting".  Basically the keyboard is arranged into rows and columns and the keyboard scans the row and column inputs to know which keys are being pressed.  In some cases if three keys are pressed together (say row1-col1, row1col2, and row2-col1) then the keyboard would erroneously think that another key (row2-col2) is also being pressed.  A keyboard encoder solves this problem.  

It may also help with "key debouncing", as well.  Also, since many encoders have a keyboard pass-thru, you can use both your arcade controls and a keyboard at the same time (if needed for admin stuff).

Hope that helps.

[Stingray]

It's already mostly wired into a keyboard. Like I said, I'm just doing this with bits I already have.  Also, I'm usure if an encoder would work with a Mac, which is what I have. This was more of a matter of seeing if I could make it work than anything else. At some point in the future I would like to go the whole way and build a MAME cabinet. I may go with an encoder at that time.

Could you possibly go into a little more detail on what ghosting means. What exactly are the limitations of a real keyboard vs. an encoder. I appreciate the reply.

-S

[Stingray]

Greg, thank you for the info on ghosting, that makes sense. You seem to have guessed what I was going to ask next, looks like we posted at the same time .

As far as the pass through function goes. I've got it wired into an old Apple ADB keyboard, which have a built in pass through. I can plug it directly into my existing keyboard.

-S

[mahuti]

Many keyboard encoders "work" with a mac. Some work very well.

The iPac for instance works great on a mac. Even has software to allow you to program it. Most of the encoders work fine on a mac, even with usb=serial adapters, many don't allow you to program them from a mac though, which I consider a major failure. I know of other Mac users that have the hagstrom encoder and love it as well.

Like I said, the iPac is programmable with a mac. I'm not sure if it can be programmed via OSX yet, though.

My cabinet for instance (which is currently running off of a PC) was built & tested with a mac.

http://homepage.mac.com/mahuti/Mamecab/

[Stingray]

Thanks for that, Mahuti. Good to know that they will work. Your cabinet looks like it turned out great.

-S

[MinerAl]

The only way to go with a Mac is an I-PAC w/ USB (so you'll need a USB port or two) or try to find an old ps2-adb converter...

There isn't an adb encoder that I'm aware of, and everything besides the I-PAC is ps2.

I'm running the I-PAC and Opti-PAC through the USB card on my beige G3-brained MacMAME cab.

[Tiger-Heli]

It's already mostly wired into a keyboard. Like I said, I'm just doing this with bits I already have.  Also, I'm usure if an encoder would work with a Mac, which is what I have. This was more of a matter of seeing if I could make it work than anything else. At some point in the future I would like to go the whole way and build a MAME cabinet. I may go with an encoder at that time.

Could you possibly go into a little more detail on what ghosting means. What exactly are the limitations of a real keyboard vs. an encoder. I appreciate the reply.

-S

Guess you got most of your answers.  For a MAC, I think your only encoder options will be the USB I-PAC from www.ultimarc.com.

For detailed info on hacks and ghosting, see http://www.mameworld.net/emuadvice/keyhack2.html

For detailed info on encoders, see http://www.fraggersxtreme.com/arcadepanels/encoder/index.htm

Ghosting is pretty much a secondary problem which can be overcome by careful key selection.  A keyboard hack is generally acceptable for MAME-only use.  The real encoder advantages are:

A - Mapping out the matrix and soldering wires to the keyboard circuit card is a PITA.
B - Difficult to change configurations if you make a mistake/change your mind.
C - If you break it, you have to start the entire process over, and
D - Most importantly, if you want one set of keys for MAME and a separate set for Atari Console emulation, or NES emulation, or some DOS game from the 80's, you can do it with an encoder.  You can't with a keyboard.

[Stingray]

Which keys are a good choice to avoid ghosting.

Sorry if I've asked a lot of questions that you guys have answered a zillion times in the past. I'm learning as I go along here!

-S

[Tiger-Heli]

Which keys are a good choice to avoid ghosting.

No way to tell (varies from keyboard to keyboard).

Read the EmuAdvice page, it covers laying out the matrix, what you can expect, suggestions for choosing keys, basically everything.

[grafixmonkey]

If you haven't already chosen your keys to avoid ghosting, I think the encoder route still saves you a whole lot of time even though you've already gotten it partly wired.  I think keyboard hacking is more of an academic adventure than anything else...  it's got that "technical achievement" aspect to it.  But encoders are usually a better solution, unless you have very few keys (like a one-player setup, less than 16 keys tops for a real good keyboard).  I built my control panel and ended up swapping the button mappings around a lot before I settled into a config.  (and I still haven't decided this one is final.)  For example, I found that the default mame keys _suck_ when run in windows.  My first three-player game, all of a sudden the Mame window was constantly flipping between windowed mode and fullscreen mode because of the Mame button assignments.  Then later I installed a Beatmania clone, separate from Mame, and had to remap a button to be the 'Enter' key or I couldn't use the program with the panel.  Then I added some new buttons, and decided my coin slots had to be different keys from my coin buttons, etc. etc. etc.

anyway, use an encoder and you'll probably be glad you did.

[paigeoliver]

I have a basic rule of thumb about deciding if an encoder is needed for a project or not.

If project involves two players simultaneously using joysticks, then it gets an encoder.

If the project does not involve 2 players simultaneously using joysticks, then it gets a keyboard or joystick hack. (You don't really run into blocking with one player setups, unless for some reason you made a one player streetfighter setup, and then picked ALL the wrong keys, then you might have trouble doing that whole "spinning chun kick" thing with Chun-Li.

Of course, I literally have 4 Mame cabinets now, have built many in the past, have two going together for other people at the moment (which need to be done before Christmas), and I have another half dozen games which may get Mamed if they keep pissing me off.

So, when you do it that much, every dollar counts. If you are only making one, then just buy an encoder. (Plus, if you hack enough keyboards and joysticks you can get REALLY fast at it, and good at picking the right ones to hack). In picking the right ones, look for HEAVY keyboards that don't have windows keys, and look for "arcade" style PC joysticks that are not analog.

[Stingray]

I did actually take apart several keyboards looking for one that has a real circuit board inside that I could solder to. I have a whole lot of extra computer equipment around the house, and like I've said in a previous post, this was just a little project using what I have available without having to shell out for extra parts. If and when I move on to the full cabinet project, I'll very likely use an encoder. I really appreciate all of the advice. Very helpful group of users on this form.

-S