Keyboard hack idea using an AND gate..

[HoopstarsGarage]

I have been asked to build a cabinet for a friend which will only play the Donkey Kong series (DK, DK Jnr. & DK3)..

To keep costs down, I thought using a hacked keyboard would probably be ok..  the only thing that bugs me is not having the shift function as found on some of the better inferfaces out there - the major reason for this is as an "exit" from the current game button..

I thought about using an AND gate who's inputs are tied to say the Player 1 and Player 2 buttons.. pressing these two buttons together would output a high, which could then activate another key on the keyboard (ie. Escape)..

Has anyone ever tried this or can anyone see any problems with this?? 


Hoops


EDIT: I do NOT want to add any other buttons to the control panel or for that matter hidden buttons on the cabinet..

[Lilwolf]

you don't need a special encoder or anything to do this.  MAME handles it perfect.


button one - press the button and twice the 'shift' key.  So it would look like this "Z" and not "S" (assuming the "Z" is the button 1 and "S" is the shift or other key)

then for exit press "Z" and then "S".  So it will say "Z" and "S"

The trouble with not adding extra buttons is that you hit both player 1 and player 2 ALL the time.  Any other combination you will also hit at times you really wish you didn't.  Add a seperate shift key isn't bad...  Or make a 3 key combination maybe.

[Tiger-Heli]

I agree with Lilwolf, but:

I would put a dedicated pause button on the cabinet, then use it as a combo so P and another button would escape the game.

[cbmeeks]

Your idea would work.  The AND gate probably has 4 outputs so you could do something like:

Player1 Start + Player2 Start + Fire1 + Fire2

If you are going to the trouble of not adding another shift button or exit button for authenticity, then you would make the key combo complex or near impossible to accidently do.

If it were me, and I wanted to keep the CP lean, I would put a pause and exit button on TOP of the cab...out of eyesight.

cbmeeks

[Chris]

To keep costs down, I thought using a hacked keyboard would probably be ok..

[HoopstarsGarage]

you don't need a special encoder or anything to do this.  MAME handles it perfect.


button one - press the button and twice the 'shift' key.  So it would look like this "Z" and not "S" (assuming the "Z" is the button 1 and "S" is the shift or other key)

then for exit press "Z" and then "S".  So it will say "Z" and "S"

The trouble with not adding extra buttons is that you hit both player 1 and player 2 ALL the time.  Any other combination you will also hit at times you really wish you didn't.  Add a seperate shift key isn't bad...  Or make a 3 key combination maybe.

Maybe I am just stupid.. but I didn't understand any of that..?

Do I need to set up something in MAME to do this??

[Tiger-Heli]

you don't need a special encoder or anything to do this.  MAME handles it perfect.


button one - press the button and twice the 'shift' key.  So it would look like this "Z" and not "S" (assuming the "Z" is the button 1 and "S" is the shift or other key)

then for exit press "Z" and then "S".  So it will say "Z" and "S"

The trouble with not adding extra buttons is that you hit both player 1 and player 2 ALL the time.  Any other combination you will also hit at times you really wish you didn't.  Add a seperate shift key isn't bad...  Or make a 3 key combination maybe.

Maybe I am just stupid.. but I didn't understand any of that..?

Do I need to set up something in MAME to do this??

Basically all you need to do is map UI CANCEL (Esc) in MAME to "1 and 2" (Mame can handle AND/OR/NOT key assignments.

Also be aware that for the hack, you need to pick keys that can be used together.   Not likely to be a problem with Donkey Kong, but I don't want people thinking that they only need six inputs so they can pick any keyboard keys and have it work fine.

[rescue161]

Just a crude drawing of my CP.

I used a keyboard hack.

Text in parentheses indicates that both buttons must be pressed for that function to occur.

To exit a game and go back to my front end, I press both the Player 1 & 2 Start buttons.

[Samstag]

Besides the above good reasons for not using AND gates, you should also consider the fact that keyboard hacks need you to connect a row and a column together, not put a high signal on a single line.

[HoopstarsGarage]

Basically all you need to do is map UI CANCEL (Esc) in MAME to "1 and 2" (Mame can handle AND/OR/NOT key assignments.

I have read the .doc files regarding the ctrl remapping and I STIIL can not make this work - I have to be missing something??

This is what I have done.

- Made a text file called "default.ini" and put it in the ctrlr directory of MAME. this is what is in that file"

UI_CANCEL               "KEYCODE_1 KEYCODE_2"

- changed the mame.ini file to read:

### Windows path and directory options ###
rompath                 roms
samplepath              samples
# inipath               <NULL> (not set)
cfg_directory           cfg
nvram_directory         nvram
memcard_directory       memcard
input_directory         inp
hiscore_directory       hi
state_directory         sta
artwork_directory       artwork
snapshot_directory      snap
diff_directory          diff
ctrlr_directory         ctrlr
ctrlr         default
cheat_file              cheat.dat
history_file            history.dat
mameinfo_file           mameinfo.dat

So what have I missed?? thanks guys

Hoops

[NoOne=NBA=]

Just hit TAB while MAME is running, and set it in the general controls menu.

[HoopstarsGarage]

Just hit TAB while MAME is running, and set it in the general controls menu.

 

You can not understand how dumb I feel right now

Thanks for the help guys..!!