<s>
A	O
keyset	B-Device
or	O
chorded	B-Device
keyboard	I-Device
(	O
also	O
called	O
a	O
chorded	O
keyset	B-Device
,	O
chord	B-Device
keyboard	I-Device
or	O
chording	B-Device
keyboard	I-Device
)	O
is	O
a	O
computer	B-Device
input	I-Device
device	I-Device
that	O
allows	O
the	O
user	O
to	O
enter	O
characters	O
or	O
commands	O
formed	O
by	O
pressing	O
several	O
keys	O
together	O
,	O
like	O
playing	O
a	O
"	O
chord	O
"	O
on	O
a	O
piano	O
.	O
</s>
<s>
A	O
chorded	B-Device
keyboard	I-Device
minus	O
the	O
board	O
,	O
typically	O
designed	O
to	O
be	O
used	O
while	O
held	O
in	O
the	O
hand	O
,	O
is	O
called	O
a	O
keyer	B-Device
.	O
</s>
<s>
Douglas	O
Engelbart	O
introduced	O
the	O
chorded	O
keyset	B-Device
as	O
a	O
computer	O
interface	O
in	O
1968	O
at	O
what	O
is	O
often	O
called	O
"	O
The	O
Mother	O
of	O
All	O
Demos	O
"	O
.	O
</s>
<s>
Unlike	O
pressing	O
a	O
chord	O
on	O
a	O
piano	O
,	O
the	O
chord	O
is	O
recognized	O
only	O
after	O
all	O
the	O
keys	O
or	O
mouse	B-Device
buttons	O
are	O
released	O
.	O
</s>
<s>
Since	O
Engelbart	O
introduced	O
the	O
keyset	B-Device
,	O
several	O
different	O
designs	O
have	O
been	O
developed	O
based	O
on	O
similar	O
concepts	O
.	O
</s>
<s>
As	O
a	O
crude	O
example	O
,	O
each	O
finger	O
might	O
control	O
one	O
key	O
which	O
corresponds	O
to	O
one	O
bit	O
in	O
a	O
byte	B-Application
,	O
so	O
that	O
using	O
seven	O
keys	O
and	O
seven	O
fingers	O
,	O
one	O
could	O
enter	O
any	O
character	O
in	O
the	O
ASCII	B-Protocol
set	O
—	O
if	O
the	O
user	O
could	O
remember	O
the	O
binary	O
codes	O
.	O
</s>
<s>
Practical	O
devices	O
generally	O
use	O
simpler	O
chords	O
for	O
common	O
characters	O
(	O
e.g.	O
,	O
Baudot	O
)	O
,	O
or	O
may	O
have	O
ways	O
to	O
make	O
it	O
easier	O
to	O
remember	O
the	O
chords	O
(	O
e.g.	O
,	O
Microwriter	B-Protocol
)	O
,	O
but	O
the	O
same	O
principles	O
apply	O
.	O
</s>
<s>
These	O
portable	O
devices	O
first	O
became	O
popular	O
with	O
the	O
wearable	B-Operating_System
computer	I-Operating_System
movement	O
in	O
the	O
1980s	O
.	O
</s>
<s>
The	O
earliest	O
known	O
chord	B-Device
keyboard	I-Device
was	O
part	O
of	O
the	O
"	O
five-needle	O
"	O
telegraph	O
operator	O
station	O
,	O
designed	O
by	O
Wheatstone	O
and	O
Cooke	O
in	O
1836	O
,	O
in	O
which	O
any	O
two	O
of	O
the	O
five	O
needles	O
could	O
point	O
left	O
or	O
right	O
to	O
indicate	O
letters	O
on	O
a	O
grid	O
.	O
</s>
<s>
The	O
first	O
widespread	O
use	O
of	O
a	O
chord	B-Device
keyboard	I-Device
was	O
in	O
the	O
stenotype	O
machine	O
used	O
by	O
court	O
reporters	O
,	O
which	O
was	O
invented	O
in	O
1868	O
and	O
is	O
still	O
in	O
use	O
.	O
</s>
<s>
In	O
1874	O
,	O
the	O
five-bit	O
Baudot	O
telegraph	O
code	O
and	O
a	O
matching	O
5-key	O
chord	B-Device
keyboard	I-Device
was	O
designed	O
to	O
be	O
used	O
with	O
the	O
operator	O
forming	O
the	O
codes	O
manually	O
.	O
</s>
<s>
But	O
telegraph	O
operators	O
were	O
already	O
using	O
typewriters	O
with	O
QWERTY	O
keyboards	O
to	O
"	O
copy	O
"	O
received	O
messages	O
,	O
and	O
at	O
the	O
time	O
it	O
made	O
more	O
sense	O
to	O
build	O
a	O
typewriter	O
that	O
could	O
generate	O
the	O
codes	O
automatically	O
,	O
rather	O
than	O
making	O
them	O
learn	O
to	O
use	O
a	O
new	O
input	B-Device
device	I-Device
.	O
</s>
<s>
Some	O
early	O
keypunch	B-Device
machines	I-Device
used	O
a	O
keyboard	O
with	O
12	O
labeled	O
keys	O
to	O
punch	O
the	O
correct	O
holes	O
in	O
paper	O
cards	O
.	O
</s>
<s>
The	O
Perkins	O
Brailler	O
,	O
first	O
manufactured	O
in	O
1951	O
,	O
uses	O
a	O
6-key	O
chord	B-Device
keyboard	I-Device
(	O
plus	O
a	O
spacebar	O
)	O
to	O
produce	O
braille	O
output	O
,	O
and	O
has	O
been	O
very	O
successful	O
as	O
a	O
mass	O
market	O
affordable	O
product	O
.	O
</s>
<s>
Researchers	O
at	O
IBM	O
investigated	O
chord	B-Device
keyboards	I-Device
for	O
both	O
typewriters	O
and	O
computer	O
data	O
entry	O
as	O
early	O
as	O
1959	O
,	O
with	O
the	O
idea	O
that	O
it	O
might	O
be	O
faster	O
than	O
touch-typing	O
if	O
some	O
chords	O
were	O
used	O
to	O
enter	O
whole	O
words	O
or	O
parts	O
of	O
words	O
.	O
</s>
<s>
Doug	O
Engelbart	O
began	O
experimenting	O
with	O
keysets	B-Device
to	O
use	O
with	O
the	O
mouse	B-Device
in	O
the	O
mid	O
1960s	O
.	O
</s>
<s>
In	O
a	O
famous	O
1968	O
demonstration	O
,	O
Engelbart	O
introduced	O
a	O
computer	O
human	O
interface	O
that	O
included	O
the	O
QWERTY	O
keyboard	O
,	O
a	O
three	O
button	O
mouse	B-Device
,	O
and	O
a	O
five	O
key	O
keyset	B-Device
.	O
</s>
<s>
Engelbart	O
used	O
the	O
keyset	B-Device
with	O
his	O
left	O
hand	O
and	O
the	O
mouse	B-Device
with	O
his	O
right	O
to	O
type	O
text	O
and	O
enter	O
commands	O
.	O
</s>
<s>
The	O
mouse	B-Device
buttons	O
marked	O
selections	O
and	O
confirmed	O
or	O
aborted	O
commands	O
.	O
</s>
<s>
Users	O
in	O
Engelbart	O
's	O
Augmentation	O
Research	O
Center	O
at	O
SRI	O
became	O
proficient	O
with	O
the	O
mouse	B-Device
and	O
keyset	B-Device
.	O
</s>
<s>
In	O
the	O
1970s	O
the	O
funding	O
Engelbart	O
's	O
group	O
received	O
from	O
the	O
Advanced	O
Research	O
Projects	O
Agency	O
(	O
ARPA	O
)	O
was	O
cut	O
and	O
many	O
key	O
members	O
of	O
Engelbart	O
's	O
team	O
went	O
to	O
work	O
for	O
Xerox	O
PARC	O
where	O
they	O
continued	O
to	O
experiment	O
with	O
the	O
mouse	B-Device
and	O
keyset	B-Device
.	O
</s>
<s>
Keychord	O
sets	O
were	O
used	O
at	O
Xerox	O
PARC	O
in	O
the	O
early	O
1980s	O
,	O
along	O
with	O
mice	O
,	O
GUIs	B-Application
,	O
on	O
the	O
Xerox	O
Star	O
and	O
Alto	B-Device
workstations	O
.	O
</s>
<s>
A	O
one	O
button	O
version	O
of	O
the	O
mouse	B-Device
was	O
incorporated	O
into	O
the	O
Apple	B-Device
Macintosh	I-Device
but	O
Steve	O
Jobs	O
decided	O
against	O
incorporating	O
the	O
chorded	O
keyset	B-Device
.	O
</s>
<s>
Stenotype	O
machines	O
(	O
sometimes	O
used	O
by	O
court	O
reporters	O
)	O
use	O
a	O
chording	B-Device
keyboard	I-Device
to	O
represent	O
sounds	O
:	O
on	O
the	O
standard	O
keyboard	O
,	O
the	O
'	O
U	O
 '	O
represents	O
the	O
sound	O
(	O
and	O
word	O
)	O
'	O
you	O
 '	O
,	O
and	O
the	O
three-key	O
trigraph	O
'	O
K	O
 '	O
'	O
A	O
 '	O
'	O
T	O
 '	O
represents	O
the	O
sound	O
and	O
word	O
'	O
cat	O
 '	O
.	O
</s>
<s>
Four	O
open-source	B-License
keyer/keyset	O
designs	O
are	O
available	O
:	O
The	O
pickey	O
,	O
a	O
PS/2	B-Device
device	O
based	O
on	O
the	O
PIC	B-Architecture
microcontroller	I-Architecture
;	O
the	O
spiffchorder	B-Device
,	O
a	O
USB	B-Protocol
device	O
based	O
on	O
the	O
Atmel	B-Architecture
AVR	I-Architecture
family	O
of	O
microcontrollers	O
;	O
the	O
FeatherChorder	O
,	O
a	O
BLE	O
chorder	O
based	O
on	O
the	O
Adafruit	O
Feather	O
,	O
an	O
all-in-one	O
board	O
incorporating	O
an	O
Arduino-compatible	O
microcontroller	O
;	O
and	O
the	O
GKOS	O
keypad	O
driver	O
for	O
Linux	B-Application
as	O
well	O
as	O
the	O
Gkos	O
library	O
for	O
the	O
Atmel/Arduino	O
open-source	B-License
board	O
.	O
</s>
<s>
Plover	O
is	O
a	O
free	O
,	O
open-source	B-License
,	O
cross-platform	O
program	O
intended	O
to	O
bring	O
real-time	O
stenographic	O
technology	O
not	O
just	O
to	O
stenographers	O
,	O
but	O
also	O
to	O
hobbyists	O
using	O
anything	O
from	O
professional	O
Stenotype	O
machines	O
to	O
low-cost	O
NKRO	O
gaming	O
keyboards	O
.	O
</s>
<s>
It	O
is	O
available	O
for	O
Linux	B-Application
,	O
Windows	O
,	O
and	O
macOS	B-Application
.	O
</s>
<s>
Joy2chord	O
is	O
a	O
chorded	B-Device
keyboard	I-Device
driver	O
for	O
Linux	B-Application
.	O
</s>
<s>
With	O
a	O
configuration	O
file	O
,	O
any	O
joystick	O
or	O
gamepad	O
can	O
be	O
turned	O
into	O
a	O
chorded	B-Device
keyboard	I-Device
.	O
</s>
<s>
This	O
design	O
philosophy	O
was	O
decided	O
on	O
to	O
lower	O
the	O
cost	O
of	O
building	O
devices	O
,	O
and	O
in	O
turn	O
lower	O
the	O
entry	O
barrier	O
to	O
becoming	O
familiar	O
with	O
chorded	B-Device
keyboards	I-Device
.	O
</s>
<s>
"	B-Device
Multiambic	I-Device
"	I-Device
keyers	I-Device
for	O
use	O
with	O
wearable	B-Operating_System
computers	I-Operating_System
were	O
invented	O
in	O
Canada	O
in	O
the	O
1970s	O
.	O
</s>
<s>
Multiambic	O
keyers	B-Device
are	O
similar	O
to	O
chording	B-Device
keyboards	I-Device
but	O
without	O
the	O
board	O
,	O
in	O
that	O
the	O
keys	O
are	O
grouped	O
in	O
a	O
cluster	O
for	O
being	O
handheld	O
,	O
rather	O
than	O
for	O
sitting	O
on	O
a	O
flat	O
surface	O
.	O
</s>
<s>
Chording	B-Device
keyboards	I-Device
are	O
also	O
used	O
as	O
portable	O
but	O
two	O
handed	O
input	B-Device
devices	I-Device
for	O
the	O
visually	O
impaired	O
(	O
either	O
combined	O
with	O
a	O
refreshable	O
braille	O
display	O
or	O
vocal	O
synthesis	O
)	O
.	O
</s>
<s>
In	O
some	O
applications	O
,	O
the	O
spacebar	O
is	O
used	O
to	O
produce	O
additional	O
chords	O
which	O
enable	O
the	O
user	O
to	O
issue	O
editing	O
commands	O
,	O
such	O
as	O
moving	O
the	O
cursor	B-Application
,	O
or	O
deleting	O
words	O
.	O
</s>
<s>
Note	O
that	O
the	O
number	O
of	O
points	O
used	O
in	O
braille	O
computing	O
is	O
not	O
6	O
,	O
but	O
8	O
,	O
as	O
this	O
allows	O
the	O
user	O
,	O
among	O
other	O
things	O
,	O
to	O
distinguish	O
between	O
small	O
and	O
capital	O
letters	O
,	O
as	O
well	O
as	O
identify	O
the	O
position	O
of	O
the	O
cursor	B-Application
.	O
</s>
<s>
As	O
a	O
result	O
,	O
most	O
newer	O
chorded	B-Device
keyboards	I-Device
for	O
braille	O
input	O
include	O
at	O
least	O
nine	O
keys	O
.	O
</s>
<s>
Touch	O
screen	O
chordic	O
keyboards	O
are	O
available	O
to	O
smartphone	B-Application
users	O
as	O
an	O
optional	O
way	O
of	O
entering	O
text	O
.	O
</s>
<s>
The	O
WriteHander	O
,	O
a	O
12-key	O
chord	B-Device
keyboard	I-Device
from	O
NewO	O
Company	O
,	O
appeared	O
in	O
1978	O
issues	O
of	O
ROM	O
Magazine	O
,	O
an	O
early	O
microcomputer	O
applications	O
magazine	O
.	O
</s>
<s>
Another	O
early	O
commercial	O
model	O
was	O
the	O
six-button	O
Microwriter	B-Protocol
,	O
designed	O
by	O
Cy	O
Endfield	O
and	O
Chris	O
Rainey	O
,	O
and	O
first	O
sold	O
in	O
1980	O
.	O
</s>
<s>
The	O
BAT	B-Device
is	O
a	O
7-key	O
hand-sized	O
device	O
from	O
Infogrip	O
,	O
and	O
has	O
been	O
sold	O
since	O
1985	O
.	O
</s>
<s>
It	O
is	O
proposed	O
for	O
the	O
hand	O
which	O
does	O
not	O
hold	O
the	O
mouse	B-Device
,	O
in	O
an	O
exact	O
continuation	O
of	O
Engelbart	O
's	O
vision	O
.	O
</s>
