[SPARCbook] keyboard keystroke loss?

[Miles Nordin]

On Wed, May 31, 2000 at 08:35:50AM -0400, Matthew Haas wrote:
> On Wed, 31 May 2000, Sunder wrote:
> > [pressing more than three keys leads to garbage]
> 
> SPARCbook 3GX
> NetBSD 1.4.2
> still on my original pointer
> 
> I have never experienced this problem... 

I also had this problem a lot with Solaris.  ^@'s and other weird 
characters would get shoved in there if I typed too fast.

When I switched to NetBSD, weird stuff stopped appearing.  I can say for 
sure that the problem got a lot better under NetBSD, but whether NetBSD 
is reading information from the keyboard cleanly or merely filtering out 
all the obviously spurious garbage after it's read, I couldn't tell you.

Anyway, as any keyboard designer will tell you, typing fast means you 
don't release the last key by the time you press the next key.  They have 
to put more wires in the keyboard to deal with this, and eventually, with 
any keyboard, you'll notice if you hold down like 8 keys at once it stops 
listening.  On my Type 5 it seems to be 3 to 5 keys, depending on which 
ones.  But, when you press keys after the ``saturation point,'' it doesn't 
generate garbage 8-bit characters and nul's like SPARCbook/Solaris--rather, 
the keys are _ignored_, like SPARCbook/NetBSD.  _Reliably._  As another 
datapoint, you'll notice the saturation point for a 3x4 touch-tone pad is 
usually 1 key.

-- 
Miles Nordin / v:+1 720 841-8308 fax:+1 530 579-8680
555 Bryant Street PMB 182 / Palo Alto, CA 94301-1700 / US

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