<s>
A	O
keyer	B-Device
is	O
a	O
device	O
for	O
signaling	O
by	O
hand	O
,	O
by	O
way	O
of	O
pressing	O
one	O
or	O
more	O
switches	O
.	O
</s>
<s>
Modern	O
keyers	B-Device
typically	O
have	O
a	O
large	O
number	O
of	O
switches	O
but	O
not	O
as	O
many	O
as	O
a	O
full-size	O
keyboard	B-Device
;	O
typically	O
between	O
four	O
and	O
fifty	O
.	O
</s>
<s>
A	O
keyer	B-Device
differs	O
from	O
a	O
keyboard	B-Device
in	O
the	O
sense	O
that	O
it	O
lacks	O
a	O
traditional	O
"	O
board	O
"	O
;	O
the	O
keys	O
are	O
arranged	O
in	O
a	O
cluster	O
which	O
is	O
often	O
held	O
in	O
the	O
hand	O
.	O
</s>
<s>
An	O
example	O
of	O
a	O
very	O
simple	O
keyer	B-Device
is	O
a	O
single	O
telegraph	O
key	O
which	O
used	O
for	O
keying	O
Morse	O
code	O
.	O
</s>
<s>
Morse	O
code	O
was	O
an	O
early	O
form	O
of	O
serial	B-Protocol
communication	I-Protocol
,	O
which	O
in	O
modern	O
times	O
is	O
usually	O
automated	O
.	O
</s>
<s>
In	O
this	O
way	O
,	O
much	O
higher	O
typing	B-Application
speeds	O
are	O
possible	O
.	O
</s>
<s>
When	O
this	O
concept	O
was	O
introduced	O
to	O
inventor	O
Steve	O
Mann	O
in	O
the	O
1970s	O
,	O
he	O
mistakenly	O
heard	O
"	O
iambic	O
"	O
as	O
"	O
biambic	O
"	O
which	O
he	O
then	O
generalized	O
to	O
include	O
various	O
"	O
polyambic	O
"	O
or	O
"	O
multiambic	O
"	O
keyers	B-Device
,	O
such	O
as	O
a	O
"	O
pentambic	O
"	O
keyer	B-Device
(	O
five	O
keys	O
,	O
one	O
for	O
each	O
finger	O
and	O
the	O
thumb	O
)	O
,	O
and	O
"	O
septambic	O
"	O
(	O
four	O
finger	O
and	O
three	O
thumb	O
buttons	O
on	O
a	O
handgrip	O
)	O
.	O
</s>
<s>
These	O
systems	O
were	O
developed	O
primarily	O
for	O
use	O
in	O
early	O
,	O
experimental	O
forms	O
of	O
wearable	B-Operating_System
computing	I-Operating_System
,	O
and	O
have	O
also	O
been	O
adapted	O
to	O
cycling	O
with	O
a	O
heads-up	B-Application
display	I-Application
in	O
projects	O
like	O
BEHEMOTH	O
by	O
Steven	O
K	O
.	O
Roberts	O
.	O
</s>
<s>
Mann	O
(	O
who	O
primarily	O
works	O
in	O
computational	B-Algorithm
photography	I-Algorithm
)	O
later	O
utilized	O
the	O
concept	O
in	O
a	O
portable	O
backpack-based	O
computer	O
and	O
imaging	O
system	O
,	O
WearCam	O
,	O
which	O
he	O
invented	O
for	O
photographic	O
light	O
vectoring	O
.	O
</s>
<s>
Such	O
keyers	B-Device
,	O
often	O
used	O
in	O
conjunction	O
with	O
wearable	B-Operating_System
computers	I-Operating_System
,	O
are	O
typically	O
one-handed	O
grips	O
.	O
</s>
<s>
Unlike	O
keyboards	B-Device
,	O
the	O
wearable	O
keyer	B-Device
has	O
no	O
board	O
upon	O
which	O
the	O
switches	O
are	O
mounted	O
.	O
</s>
<s>
Additionally	O
,	O
by	O
providing	O
some	O
other	O
function	O
–	O
such	O
as	O
simultaneous	O
grip	O
of	O
flash	O
light	O
and	O
keying	O
–	O
the	O
keyer	B-Device
is	O
effectively	O
hands-free	O
,	O
in	O
the	O
sense	O
that	O
one	O
would	O
still	O
be	O
holding	O
the	O
light	O
source	O
anyway	O
.	O
</s>
<s>
Chorded	B-Device
or	I-Device
chording	I-Device
keyboards	I-Device
have	O
also	O
been	O
developed	O
,	O
and	O
are	O
intended	O
to	O
be	O
used	O
while	O
seated	O
having	O
multiple	O
keys	O
mounted	O
to	O
a	O
board	O
rather	O
than	O
a	O
portable	O
grip	O
.	O
</s>
<s>
It	O
is	O
otherwise	O
a	O
standard	O
QWERTY	O
keyboard	B-Device
of	O
full	O
size	O
.	O
</s>
<s>
It	O
,	O
and	O
many	O
other	O
innovations	O
in	O
keyboard	B-Device
controls	O
,	O
were	O
designed	O
to	O
deal	O
with	O
hand	O
disabilities	O
in	O
particular	O
.	O
</s>
