6 May
2012
6 May
'12
1:47 p.m.
On 6 May 2012 at 13:06, Eric Smith wrote:
Very few keyboards with either USB or PS/2 interfaces
have more than
2-key rollover. There are almost always cases where a third key
pressed simultaneously will cause a phantom fourth key. This doesn't
mean that there aren't a lot of cases where three keys will work
correctly, only that there are some cases that it will fail. Usually
they do wire the "modifier" keys (shift, control, alt, etc.) so that
they can't produce phantom keys, but some combinations of three or
more "normal" keys will produce phantom keys.
Two simple demonstrations of good keyboard encoding that I'm aware of
are these (the Model M fails both)
1. Press the ASDW keys and hold down. See if any other keys
register.
2. Press right and left shift and hold down. Type "The quick brown
fox jumps over the lazy dog".
Since I don't have a USB keyboard (preferring model Ms for the feel),
how do USB keyboards fare?
--Chuck