<s>
The	O
space-cadet	B-Device
keyboard	I-Device
is	O
a	O
keyboard	O
designed	O
by	O
John	O
L	O
.	O
Kulp	O
in	O
1978	O
and	O
used	O
on	O
Lisp	B-Operating_System
machines	I-Operating_System
at	O
Massachusetts	O
Institute	O
of	O
Technology	O
(	O
MIT	O
)	O
,	O
which	O
inspired	O
several	O
still-current	O
jargon	O
terms	O
in	O
the	O
field	O
of	O
computer	B-General_Concept
science	I-General_Concept
and	O
influenced	O
the	O
design	O
of	O
Emacs	B-Application
.	O
</s>
<s>
It	O
was	O
inspired	O
by	O
the	O
Knight	B-Device
keyboard	I-Device
,	O
which	O
was	O
developed	O
for	O
the	O
Knight	O
TV	O
system	O
,	O
used	O
with	O
MIT	O
's	O
Incompatible	B-Application
Timesharing	I-Application
System	I-Application
.	O
</s>
<s>
The	O
space-cadet	B-Device
keyboard	I-Device
was	O
equipped	O
with	O
seven	O
modifier	B-Device
keys	I-Device
:	O
four	O
keys	O
for	O
bucky	O
bits	O
(	O
,	O
,	O
,	O
and	O
)	O
,	O
and	O
three	O
shift	O
keys	O
,	O
called	O
,	O
,	O
and	O
(	O
which	O
was	O
labeled	O
on	O
the	O
front	O
of	O
the	O
key	O
;	O
the	O
top	O
was	O
labeled	O
)	O
.	O
</s>
<s>
had	O
been	O
introduced	O
on	O
the	O
earlier	O
Knight	B-Device
keyboard	I-Device
,	O
while	O
and	O
were	O
introduced	O
by	O
this	O
keyboard	O
.	O
</s>
<s>
Each	O
group	O
was	O
in	O
a	O
row	O
,	O
thus	O
allowing	O
easy	O
chording	B-Device
,	O
or	O
pressing	O
of	O
several	O
modifier	B-Device
keys	I-Device
;	O
for	O
example	O
,	O
could	O
be	O
pressed	O
with	O
the	O
fingers	O
of	O
one	O
hand	O
,	O
while	O
the	O
other	O
hand	O
pressed	O
another	O
key	O
.	O
</s>
<s>
By	O
combining	O
the	O
modifier	B-Device
keys	I-Device
,	O
it	O
is	O
possible	O
to	O
make	O
.	O
</s>
<s>
This	O
attitude	O
shaped	O
the	O
interface	O
of	O
Emacs	B-Application
;	O
compare	O
the	O
use	O
of	O
the	O
key	O
in	O
vi	B-Application
,	O
due	O
to	O
the	O
convenient	O
position	O
of	O
the	O
key	O
on	O
the	O
ADM-3A	B-Device
terminal	O
.	O
</s>
<s>
Emacs	B-Application
uses	O
"	O
M-	O
"	O
as	O
the	O
prefix	O
for	O
when	O
describing	O
key	O
presses	O
:	O
the	O
"	O
M-	O
"	O
stood	O
for	O
on	O
the	O
space-cadet	B-Device
keyboard	I-Device
,	O
and	O
when	O
Emacs	B-Application
was	O
ported	O
to	O
PCs	O
,	O
the	O
key	O
was	O
used	O
in	O
place	O
of	O
.	O
</s>
