Keyboard And Ghosting


mcobit

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Jul 28, 2008
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Maybe you know the issue, that when the inputmatrix of a pc-keyboard isn't optimised, you can press only 3 or 4 buttons at once and the rest will be ignored or there may occour some other letters in some combinations.

Will the Pandora use a keyboard where this will not occour?

Will the Keys be linked to the D-Pad and Actionbuttons in the same matrix or will the gamingcontrols act like a gamepad and the keyboard will be a extra device?
 
mcobit said:
Maybe you know the issue, that when the inputmatrix of a pc-keyboard isn't optimised, you can press only 3 or 4 buttons at once and the rest will be ignored or there may occour some other letters in some combinations.

Will the Pandora use a keyboard where this will not occour?

Will the Keys be linked to the D-Pad and Actionbuttons in the same matrix or will the gamingcontrols act like a gamepad and the keyboard will be a extra device?

Thats a great question, i've been wondering that my self. I mean it will make a huge difference depending on which ever it is. I really hope it doesnt have a matrix. And then every button can be read indivually.

Morten
 
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I just fear, that when you press bottom-right on the d-pad and have to press two action buttons or keys on the keyboard simultaniously the matrix can't handle it.
 
AFAIK Pandora's keyboard only has a 2-key buffer - so you can only do 2-key combinations on the actual keybaord. The action buttons, however, have no such limit, including the three down the middle, so as long as we're able to bind them to the important modifier buttons, it shouldn't matter.

This is, of course, assuming that what you're talking about is pressing several keys at once, as opposed to what used to happen in DOS where if you typed faster than then computer recognized characters (or when it was doing something else in preparation for the time when it wasn't - e.g. as autoexec.bat was coming to an end at startup) then it would only read ahead by a fairly short amount. If that's what you're talking about, then it's up to Linux, but shouldn't be a problem.
 
No, what i'm talking about is indeed pressing several buttons at once.
But when there are just 2-button-combinations on the keyboard, i see a problem, when i want to use combinations like alt-contr-del or other commands that need 3 keys in a desktop environment for example.

Edit: OK, I get your point. But i doubt, that when you map the modifier buttons to this keys will they be still usable in the games or will they react like the keys + the game-command they are set as.

I expirienced problems with the joy2key mapping program in my arcade cab for this reason.
 
mcobit said:
No, what i'm talking about is indeed pressing several buttons at once.
But when there are just 2-button-combinations on the keyboard, i see a problem, when i want to use combinations like alt-contr-del or other commands that need 3 keys in a desktop environment for example

Sticky keys solve this problem.

You can't do a 3-key combo without sticky keys anyway - You only have two thumbs!
 
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You don't have to use your thumbs, but that's how it's designed to be used. Any solution that requires you to find a table to set your hendheld device down upon to perform a key combo is not an acceptable one. Every qwerty cell phone and internet tablet uses sticky keys because that is the best way to handle key combos with a handheld device.
 
mcobit said:
Maybe you know the issue, that when the inputmatrix of a pc-keyboard isn't optimised, you can press only 3 or 4 buttons at once and the rest will be ignored or there may occour some other letters in some combinations.

Will the Pandora use a keyboard where this will not occour?
It seems not:

QUOTE
Currently the keypad is designed to handle one or two buttons pressed at once. Pressing three keys causes a ghost key which fakes a fourth key press. This is not a bug, but the functionality of a scanning keypad matrix. The easy solution is to put diodes on each key but it adds cost. Are some of the suggestions here to use three keys at once? If so, and if it is actually important and not just to get at that one favorite key you'd like to map, the extra parts will need to be populated.
 
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OK, sorry, didn't get this one...

But when the gaming-controls will not suffer from this limitations i will be fine with it.

Thanks!
 
Hi there, so what are the practical implications of this design choice? Other than simple text entry in C64/Amiga games ('enter your name' etc), I should be ok I think. I'll mainly playing C64/Amiga/Genesis/homebrew with Pandora. Also web & email, but that's one key at a time stuff, maybe two (shortcut keys to close tabs, etc.).

On the other hand, what if all I played were 3rd person shooters with the direction keys and weapons all mapped to the keyboard, or 2d fighting games (Street Fighter, etc)? I don't happen to play any of those, but is that the type of thing we're talking about? Or am I way off? :) Directions will be mapped to the d-pad or nubs anyways, right?

Thanks for any more info. I don't think this design limitation will effect me, but maybe I'm not understanding the issue.
 
EmuGuy said:
Hi there, so what are the practical implications of this design choice?

It really won't be an issue for 99% of games / applications. Sticky function keys handle the problem of 2-4 key combos for applications, and as for gaming, most people will map the primary movement / action keys to the d-pad and buttons. Nearly all keyboards use a matrix input system and can't handle more than 3 or 4 simultaneous key presses. The Pandora is a bit more limited to two simultaneous keys, but like I said, it will hardly ever be a problem.
 
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Username said:
Does the 2-key limit also occur with plugging in separate keyboards?
If the seperate keyboard has that limitation (or worse), yes - it's no longer anything to do with the Pandora then.
 
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Username said:
Does the 2-key limit also occur with plugging in separate keyboards?
Yes, this brings a few questions for me as well. Like the post above me, does the keyboard matrix also limit the number of simultaneous key presses for an external USB keyboard as well or only the built-in keyboard?

I work on the road a lot over SSH/Telnet sessions and I can type almost 90 wpm tops. If I buy a Pandora, this will be a requirement for it to be able to handle my fast typing without skipping characters. Granted, if I am typing 90 wpm, it won't be on the internal keyboard, but again that brings up my question about if the matrix affects the performace of externals.
 
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[sarcasm/]Yeah i also have a concern. Because I'm a actually a robot and i write approximately 10.000 word per second, and I'm wondering if the Pandora can handle all that?


And what if you're bored or frustrated, and then starts to just slamming your fingers really fast, will the Pandora be able to recognize the fast stream of more of less random letters(of course it always ends up with dfgdfg...) [/sarcasm]

On a less sarcastic note, i think it should be able to handle it, and i base that on absolutely nothing.

Can't you just type slower? :lol:
 
The number of simultaneous keypresses on USB keyboards will not be restricted by the pandora
 
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