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General Category => Amstrad CPC hardware => Topic started by: arnoldemu on 09:09, 24 October 11

Title: keyboard clash
Post by: arnoldemu on 09:09, 24 October 11
Doesn't happen on my cpc664! Tested and confirmed.

I've seen it on cpc464 with newer keyboard and cpc6128, and even plus. But not my cpc664!
Title: Re: keyboard clash
Post by: Ygdrazil on 09:41, 24 October 11
What do you mean by keyboard clash??

/Ygdrazil

Quote from: arnoldemu on 09:09, 24 October 11
Doesn't happen on my cpc664! Tested and confirmed.

I've seen it on cpc464 with newer keyboard and cpc6128, and even plus. But not my cpc664!
Title: Re: keyboard clash
Post by: Bryce on 09:42, 24 October 11
The circuits are identical, so what makes the 664 different?

Bryce.
Title: Re: keyboard clash
Post by: Ygdrazil on 10:12, 24 October 11
Maybe this http://www.cpcwiki.eu/index.php/Programming:Keyboard_scanning#Keyboard_clash (http://www.cpcwiki.eu/forum/../index.php/Programming:Keyboard_scanning#Keyboard_clash)

/ygdrazil

Quote from: Ygdrazil on 09:41, 24 October 11
What do you mean by keyboard clash??

/Ygdrazil
Title: Re: keyboard clash
Post by: arnoldemu on 12:27, 24 October 11
Quote from: Bryce on 09:42, 24 October 11
The circuits are identical, so what makes the 664 different?

Bryce.
I don't know, but there is something strange going on when I press multiple keys. Perhaps clash should happen, but it doesn't.
Pressing I,O,P together doesn't produce another key. If I try and hold down more keys, it then automatically releases some other keys which are already pressed.
It's not possible to hold down all keys like it is on the other keyboards.

Perhaps the keyboard is broken in some way, but every key does work on the keyboard... I tested that.

Title: Re: keyboard clash
Post by: Bryce on 12:48, 24 October 11
Maybe they added some sort of "intelligent filtering" in the Firmware?

Bryce.
Title: Re: keyboard clash
Post by: MacDeath on 06:58, 25 October 11
Perhaps the 664 keyboard was faulty for a reason.

I mean, those are notoriously faulty yet clashless.
Title: Re: keyboard clash
Post by: TFM on 20:11, 25 October 11
Quote from: Bryce on 12:48, 24 October 11
Maybe they added some sort of "intelligent filtering" in the Firmware?

Bryce.

The firmware can't overcome the faults of the hardware. But maybe the keyboard itself is modified.

I have 6128 without keyboard clash - due to a Siemens keyboard (which looks obviously different).
Title: Re: keyboard clash
Post by: TFM on 20:14, 25 October 11
Quote from: MacDeath on 06:58, 25 October 11
Perhaps the 664 keyboard was faulty for a reason.

I mean, those are notoriously faulty yet clashless.

Where shall be the gain in being faulty? Arnoldemus keyboard is a "gain of function" mutation, not a "loss of function" ;-)

I have a nice tool under FutureOS (Show Keys), that will show you the keyboard matrix semi-graphically. Use this to verify your keyboards (ESC ends!). Link:
http://www.colorado-boys-muenchen.de/users/futureos/files/FutureOS_Program_Sources.zip (http://www.colorado-boys-muenchen.de/users/futureos/files/FutureOS_Program_Sources.zip)
Title: Re: keyboard clash
Post by: arnoldemu on 20:56, 25 October 11
Quote from: TFM/FS on 20:14, 25 October 11

Where shall be the gain in being faulty? Arnoldemus keyboard is a "gain of function" mutation, not a "loss of function" ;-)

I have a nice tool under FutureOS (Show Keys), that will show you the keyboard matrix semi-graphically. Use this to verify your keyboards (ESC ends!). Link:
http://www.colorado-boys-muenchen.de/users/futureos/files/FutureOS_Program_Sources.zip (http://www.colorado-boys-muenchen.de/users/futureos/files/FutureOS_Program_Sources.zip)
I used my own program that performs a similar function.
And this is how I verified my CPC664 keyboard is unique.
Title: Re: keyboard clash
Post by: arnoldemu on 20:57, 25 October 11
Quote from: TFM/FS on 20:11, 25 October 11

The firmware can't overcome the faults of the hardware. But maybe the keyboard itself is modified.

I have 6128 without keyboard clash - due to a Siemens keyboard (which looks obviously different).
The siemens keyboard is a special adapted keyboard? or it's the same look as a normal 6128 but it has a different manufacturer?
Title: Re: keyboard clash
Post by: TFM on 22:51, 25 October 11
Quote from: arnoldemu on 20:57, 25 October 11
The siemens keyboard is a special adapted keyboard? or it's the same look as a normal 6128 but it has a different manufacturer?

It's completely different. I menetioned to point to the keyboard of the CPC, and to "unblame" the non-keyboard-part of the CPC  :)
Title: Re: keyboard clash
Post by: arnoldemu on 08:13, 26 October 11
Quote from: TFM/FS on 22:51, 25 October 11

It's completely different. I menetioned to point to the keyboard of the CPC, and to "unblame" the non-keyboard-part of the CPC  :)
As I thought... I am sure it makes coding much more enjoyable.
Title: Re: keyboard clash
Post by: Bryce on 08:49, 26 October 11
It would be possible to correct the clash in Firmware by filtering the results: ie: If keybaord input > 4 and = (the four keys that happen in a clash) then ignore the fourth character.

If the Siemens keyboard uses a completely different matrix layout, then it must have different firmware too? Or is it a PS/2 keyboard connected to a standard 6128 via a controller?

Bryce.
Title: Re: keyboard clash
Post by: TFM on 05:02, 27 October 11
Quote from: Bryce on 08:49, 26 October 11
It would be possible to correct the clash in Firmware by filtering the results: ie: If keybaord input > 4 and = (the four keys that happen in a clash) then ignore the fourth character.

Haha, so which one of the four keys is the wrong one? Imagine first you "see" two pressed keys then it's four. All you can do it guess! And I rather take a Guinnes than to guess.

Quote from: Bryce on 08:49, 26 October 11
If the Siemens keyboard uses a completely different matrix layout, then it must have different firmware too? Or is it a PS/2 keyboard connected to a standard 6128 via a controller?
Bryce.

A bit a rewiring and all is fine :-)
Title: Re: keyboard clash
Post by: MacDeath on 13:21, 27 October 11
Got to remember the original series of 664 had faulty keyboards... so many got changed, perhaps with better 3rd party companies ones, hence superior and clashless..?
Title: Re: keyboard clash
Post by: Bryce on 15:13, 27 October 11
The quality of the keyboard doesn't effect whether the clash happens or not. Only the scanning method and keyboard architecture influences whether there will/can be clashes. If they didn't change the scanning or architecture, then even the best keyboard will still produce clashes. I can see no electronic differences between the 464 and the 664, so they have obviously changed something in how they scan the keys.

Bryce.
Title: Re: keyboard clash
Post by: TFM on 18:38, 27 October 11
Na die werden hald eine Hand voll Dioden eingesträut haben.

English: May they have added some diodes.
Title: Re: keyboard clash
Post by: Bryce on 20:17, 27 October 11
They could have, but they didn't, otherwise they would be in the schematic.

Bryce.
Title: Re: keyboard clash
Post by: TFM on 00:12, 28 October 11
Quote from: Bryce on 20:17, 27 October 11
They could have, but they didn't, otherwise they would be in the schematic.

Bryce.

Let me know if I'm wrong. There is one schematic, and there are two kinds of keyboards?  :-X
Title: Re: keyboard clash
Post by: arnoldemu on 07:44, 28 October 11
Quote from: TFM/FS on 00:12, 28 October 11

Let me know if I'm wrong. There is one schematic, and there are two kinds of keyboards?  :-X
I think it's the actual keyboard itself. But I will not open it to find out more because I would not be able to put it back together again and I don't want a broken CPC664.

The other possibility is that the keyboard is starting to fail (although all the keys work on their own)... because if I press lots of keys together the keyboard decides it doesn't want some of the keys I already pressed to be down and releases them for me (in terms of what the cpc sees).

Really, others who have cpc664 should verify my findings.

I tested so far:
CPC464 old keyboard, CPC6128, CPC664, CPC464 new keyboard, KC Compact. All except my CPC664 show keyboard clash.
Title: Re: keyboard clash
Post by: Bryce on 08:22, 28 October 11
Well according to the schematics, and mainboard pictures on the wiki (I don't have a real 664 to look at), the 664 is identical to the 464 and uses exactly the same components. If they did use diodes, then they must be mounted under the keyboard, which I very much doubt.
what I suspect they did was to block ALL multiple presses in the firmware, by only accepting one key input per scan, ie: the first key detected is the only one that gets processed. This would stop clashes, but also have some negative effects when you are beating on multiple keys while playing your favourite game.

Bryce.
Title: Re: keyboard clash
Post by: TFM on 04:57, 29 October 11
Well, as Arnoldemu suggested, tests on 664 CPCs are needed, anything else is just grey theory.

Volunteers please ;-)
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