<s>
In	O
computer	B-General_Concept
science	I-General_Concept
,	O
a	O
digital	B-Device
electronic	I-Device
computer	I-Device
is	O
a	O
computer	O
machine	O
which	O
is	O
both	O
an	O
electronic	O
computer	O
and	O
a	O
digital	O
computer	O
.	O
</s>
<s>
Examples	O
of	O
digital	B-Device
electronic	I-Device
computers	I-Device
include	O
the	O
IBM	B-Device
PC	I-Device
,	O
the	O
Apple	B-Device
Macintosh	I-Device
,	O
and	O
modern	O
smartphones	B-Application
.	O
</s>
<s>
When	O
computers	O
that	O
were	O
both	O
digital	O
and	O
electronic	O
appeared	O
,	O
they	O
displaced	O
almost	O
all	O
other	O
kinds	O
of	O
computers	O
,	O
but	O
computation	O
has	O
historically	O
been	O
performed	O
in	O
various	O
non-digital	O
and	O
non-electronic	O
ways	O
:	O
the	O
Lehmer	O
sieve	O
is	O
an	O
example	O
of	O
a	O
digital	O
non-electronic	O
computer	O
,	O
while	O
analog	O
computers	O
are	O
examples	O
of	O
non-digital	O
computers	O
which	O
can	O
be	O
electronic	O
(	O
with	O
analog	O
electronics	O
)	O
,	O
and	O
mechanical	B-Device
computers	I-Device
are	O
examples	O
of	O
non-electronic	O
computers	O
(	O
which	O
may	O
be	O
digital	O
or	O
not	O
)	O
.	O
</s>
<s>
All	O
kinds	O
of	O
computers	O
,	O
whether	O
they	O
are	O
digital	O
or	O
analog	O
,	O
and	O
electronic	O
or	O
non-electronic	O
,	O
can	O
be	O
Turing	B-Algorithm
complete	I-Algorithm
if	O
they	O
have	O
sufficient	O
memory	B-General_Concept
.	O
</s>
<s>
A	O
digital	B-Device
electronic	I-Device
computer	I-Device
is	O
not	O
necessarily	O
a	O
programmable	O
computer	O
,	O
a	O
stored	O
program	O
computer	O
,	O
or	O
a	O
general	O
purpose	O
computer	O
,	O
since	O
in	O
essence	O
a	O
digital	B-Device
electronic	I-Device
computer	I-Device
can	O
be	O
built	O
for	O
one	O
specific	O
application	O
and	O
be	O
non-reprogrammable	O
.	O
</s>
<s>
,	O
most	O
personal	B-Device
computers	I-Device
and	O
smartphones	B-Application
in	O
people	O
's	O
homes	O
that	O
use	O
multicore	B-Architecture
central	B-General_Concept
processing	I-General_Concept
units	I-General_Concept
(	O
such	O
as	O
AMD	O
FX	O
,	O
Intel	B-Device
Core	I-Device
i7	I-Device
,	O
or	O
the	O
multicore	B-Architecture
varieties	O
of	O
ARM-based	O
chips	O
)	O
are	O
also	O
parallel	B-Operating_System
computers	I-Operating_System
using	O
the	O
MIMD	B-Operating_System
(	O
multiple	B-Operating_System
instruction	I-Operating_System
,	I-Operating_System
multiple	I-Operating_System
data	I-Operating_System
)	O
paradigm	O
,	O
a	O
technology	O
previously	O
only	O
used	O
in	O
digital	O
electronic	O
supercomputers	B-Architecture
.	O
</s>
<s>
,	O
most	O
digital	O
electronic	O
supercomputers	B-Architecture
are	O
also	O
cluster	B-Architecture
computers	I-Architecture
,	O
a	O
technology	O
that	O
can	O
be	O
used	O
at	O
home	O
in	O
the	O
form	O
of	O
small	O
Beowulf	B-Operating_System
clusters	I-Operating_System
.	O
</s>
<s>
Parallel	B-Operating_System
computation	I-Operating_System
is	O
also	O
possible	O
with	O
non-digital	O
or	O
non-electronic	O
computers	O
.	O
</s>
<s>
An	O
example	O
of	O
a	O
parallel	B-Operating_System
computation	I-Operating_System
system	O
using	O
the	O
abacus	B-Application
would	O
be	O
a	O
group	O
of	O
human	O
computers	O
using	O
a	O
number	O
of	O
abacus	B-Application
machines	O
for	O
computation	O
and	O
communicating	O
using	O
natural	O
language	O
.	O
</s>
<s>
A	O
digital	O
computer	O
can	O
perform	O
its	O
operations	O
in	O
the	O
decimal	B-Application
system	O
,	O
in	O
binary	O
,	O
in	O
ternary	B-Algorithm
or	O
in	O
other	O
numeral	O
systems	O
.	O
</s>
<s>
,	O
all	O
digital	B-Device
electronic	I-Device
computers	I-Device
commonly	O
used	O
,	O
whether	O
personal	B-Device
computers	I-Device
or	O
server	B-Application
computers	I-Application
or	O
supercomputers	B-Architecture
,	O
are	O
working	O
in	O
the	O
binary	O
number	O
system	O
and	O
also	O
use	O
binary	O
logic	O
.	O
</s>
<s>
A	O
few	O
ternary	B-Device
computers	I-Device
using	O
ternary	B-Language
logic	I-Language
were	O
built	O
mainly	O
in	O
the	O
Soviet	O
Union	O
as	O
research	O
projects	O
.	O
</s>
<s>
A	O
digital	B-Device
electronic	I-Device
computer	I-Device
is	O
not	O
necessarily	O
a	O
transistorized	B-Device
computer	I-Device
:	O
before	O
the	O
advent	O
of	O
the	O
transistor	B-Application
,	O
computers	O
used	O
vacuum	O
tubes	O
.	O
</s>
<s>
The	O
transistor	B-Application
enabled	O
electronic	O
computers	O
to	O
become	O
much	O
more	O
powerful	O
,	O
and	O
recent	O
and	O
future	O
developments	O
in	O
digital	O
electronics	O
may	O
enable	O
humanity	O
to	O
build	O
even	O
more	O
powerful	O
electronic	O
computers	O
.	O
</s>
<s>
People	O
living	O
in	O
the	O
beginning	O
of	O
the	O
21st	O
century	O
use	O
digital	B-Device
electronic	I-Device
computers	I-Device
for	O
storing	B-General_Concept
data	O
,	O
such	O
as	O
photos	O
,	O
music	O
,	O
documents	O
,	O
for	O
performing	O
complex	O
mathematical	O
computations	O
,	O
or	O
for	O
communication	O
,	O
commonly	O
over	O
a	O
worldwide	O
computer	B-Architecture
network	I-Architecture
called	O
the	O
internet	O
which	O
connects	O
many	O
of	O
the	O
world	O
's	O
computers	O
.	O
</s>
<s>
All	O
these	O
activities	O
made	O
possible	O
by	O
digital	B-Device
electronic	I-Device
computers	I-Device
could	O
,	O
in	O
essence	O
,	O
be	O
performed	O
with	O
non-digital	O
or	O
non-electronic	O
computers	O
if	O
they	O
were	O
sufficiently	O
powerful	O
,	O
but	O
it	O
was	O
only	O
the	O
combination	O
of	O
electronics	O
technology	O
with	O
digital	O
computation	O
in	O
binary	O
that	O
enabled	O
humanity	O
to	O
reach	O
the	O
computation	O
power	O
necessary	O
for	O
today	O
's	O
computing	O
.	O
</s>
<s>
Advances	O
in	O
quantum	B-Architecture
computing	I-Architecture
,	O
DNA	B-Application
computing	I-Application
,	O
optical	O
computing	O
or	O
other	O
technologies	O
could	O
lead	O
to	O
the	O
development	O
of	O
more	O
powerful	O
computers	O
in	O
the	O
future	O
.	O
</s>
<s>
The	O
philosophy	O
of	O
digital	B-General_Concept
physics	I-General_Concept
views	O
the	O
universe	O
as	O
being	O
digital	O
.	O
</s>
