Anyone had any problems with ghosting/blocking with a kb hack?

[Ilitirit]

I've just finished my control panel and I must say it was much easier than expected (mainly cos I let others take care of the tough bits  ).  Its a pretty standard setup: 2 j-sticks, 6 game buttons per player, 2 start, 1 'insert coin' and 4 mame related.

I'm using a keyboard hack and I must say I'm pretty damn impressed.  We had an hour 2-player Streetfighter 2 test session and it worked perfectly (*sort of).

Now, I'm kinda confused as to why people say ghosting and blocking is a problem with kb hacks because if I understand correctly, the problem only arises if 2 keys on the same row of your kb matrix are pressed simultaneously.  So theoretically on a 16x8 matrix there should be at least 16 buttons which can be depressed simultaneously with no chance of blocking or ghosting.  So am I correct in assuming that is always possible to design one's controls on a kb which utilises a 16x8 matrix in such a way that there is virtually zero chance of ghosting or blocking (in a practical gaming setup)?  Or was I just lucky this time?


*The kb I hacked used a 14x8 matrix (the year on the IC was 1980!).  I got around the problem of ghosting and blocking by *intentionally* placing buttons 1 and 6 on the same row for each player because I don't know of any games that require those two buttons to be depressed at the same time.  Unsurprisingly, if I do press them together while I'm playing, blocking does occur, and if first depress a few other buttons and then button 1 and 6, then the 'p' key gets ghosted.  Luckily this isn't a problem because of the combination I chose .

[rampy]

well i'm sure lots of people have, and other people have had their keyboard hacks work fine.

The bottom line is it working for you?  If it's working for you, you have found and mapped 1 of the rare holy artifacts of antiochs, congrats and enjoy!

Do some more playtesting with another game... Isn't there a game(s) where you do super moves where you hit all 6 buttons at once? MvsC ?  If after extensive playtesting (beware of 2nd players complaining of ghosts/blocking when it's really their technique =P though) it works good enough for you, your set... if not maybe upgrade to a hagstrom, ipac or forthcoming key whiz keyboard encoder.

*Shrug*
 
Rampy

[Ilitirit]

Isn't there a game(s) where you do super moves where you hit all 6 buttons at once? MvsC ?

We tried MvsC and it worked fine. We could manage both players doing 3 button supers with no problems but i dunno if there are super moves which require all 6 buttons.  If there are, then thats just too bad.  I still have my gamepad  

[rampy]

Isn't there a game(s) where you do super moves where you hit all 6 buttons at once? MvsC ?

We tried MvsC and it worked fine. We could manage both players doing 3 button supers with no problems but i dunno if there are super moves which require all 6 buttons.  If there are, then thats just too bad.  I still have my gamepad  

Cool,.

See I dont' know how to play MvsC so I just mash a lot =)

good luck,
rampy

[TapeWurm]

I did a keyboard hack with a cheapy keyboard. With the exception of the tiny connection points, it was going pretty easy and smooth. I finally wired up 16 buttons and two controls. Everything was good UNLESS you started using games that used 4-6 buttons and were playing 2 players. All those keypresses would start to block out other buttons making some games completely worthless if playing 2 players. No problems from 1 player games at all. I'm redoing my whole cab and going with the I-pac this time. No worries and waaay easier to connect to. Kudos on your good hack though.

[eightbit]

*The kb I hacked used a 14x8 matrix (the year on the IC was 1980!).  I got around the problem of ghosting and blocking by *intentionally* placing buttons 1 and 6 on the same row for each player because I don't know of any games that require those two buttons to be depressed at the same time.  Unsurprisingly, if I do press them together while I'm playing, blocking does occur, and if first depress a few other buttons and then button 1 and 6, then the 'p' key gets ghosted.  Luckily this isn't a problem because of the combination I chose .

Keyboard hack can work but as you've proven you can get it to ghost and block. Depending on what games you play you many never run into a problem during game play, but you might.

There are other inputs you can put in the same row. Like up and down, its just not possible to push up and down at the same time on the same joystick. You can also usually get away with your start and coin buttons in the same row as other keys as you usually aren't mashing while pressing the start button.

Kudo's to you for attempting and successfully completing a keyboard hack. You are now worthy to join the inner circle of keyboard hackers. Though I don't recomend actually going into the inner circle because some of those guys don't believe in keyboard encoders or showers.

I was impressed with myself for doing a sidewinder hack. Not near as impressive as what you did, they won't let me in the inner circle. I don't know why, maybe I shower to much. With the sidewinder hack most of the work is done for you all you have to do is solder wires to the marked holes, I think even Snaaack has done it.

[Chris]

So am I correct in assuming that is always possible to design one's controls on a kb which utilises a 16x8 matrix in such a way that there is virtually zero chance of ghosting or blocking (in a practical gaming setup)?  Or was I just lucky this time?

Not necessarily, because many spots in the matrix may be blank, and there may be other keys you don't want in combination.  For example, I'm not sure I would map CTRL, ALT, and DEL to your favorite three-button combo... and if you're in Windows, you need to watch out for combos like ALT and F4, CTRL and ESC, ALT and TAB, etc.In addition, I tried to keep Player 2's controls away from the row with the Player 1 start and coin buttons, and vice versa, on the theory that one player might be coining up while another player is playing.

--Chris

[Ilitirit]

Not necessarily, because many spots in the matrix may be blank, and there may be other keys you don't want in combination.  For example, I'm not sure I would map CTRL, ALT, and DEL to your favorite three-button combo... and if you're in Windows, you need to watch out for combos like ALT and F4, CTRL and ESC, ALT and TAB, etc.

aaah... of course.  i thought there was something i was forgetting.