<s>
Universal	B-Device
memory	I-Device
refers	O
to	O
a	O
computer	B-General_Concept
data	I-General_Concept
storage	I-General_Concept
device	O
combining	O
the	O
cost	O
benefits	O
of	O
DRAM	O
,	O
the	O
speed	O
of	O
SRAM	B-Architecture
,	O
the	O
non-volatility	B-General_Concept
of	O
flash	B-Device
memory	I-Device
along	O
with	O
infinite	O
durability	O
,	O
and	O
longevity	O
.	O
</s>
<s>
A	O
personal	B-Device
computer	I-Device
might	O
include	O
a	O
few	O
megabytes	O
of	O
fast	O
but	O
volatile	B-General_Concept
and	O
expensive	O
SRAM	B-Architecture
as	O
the	O
CPU	B-General_Concept
cache	I-General_Concept
,	O
several	O
gigabytes	O
of	O
slower	O
DRAM	O
for	O
program	O
memory	O
,	O
and	O
128	O
GB-8	O
TB	O
of	O
the	O
slow	O
but	O
non-volatile	B-General_Concept
flash	B-Device
memory	I-Device
or	O
1-10	O
terabytes	O
of	O
"	O
spinning	O
platters	O
"	O
hard	B-Device
disk	I-Device
drive	I-Device
for	O
long-term	O
storage	O
.	O
</s>
<s>
For	O
a	O
memory	O
technology	O
to	O
be	O
considered	O
a	O
universal	B-Device
memory	I-Device
,	O
it	O
would	O
need	O
to	O
have	O
best	O
characteristics	O
of	O
several	O
memory	O
technologies	O
.	O
</s>
<s>
-	O
be	O
sufficiently	O
large	O
for	O
common	O
operating	O
systems	O
and	O
application	O
programs	O
,	O
yet	O
affordablelike	O
hard	B-Device
disk	I-Device
drives	I-Device
.	O
</s>
<s>
Many	O
types	O
of	O
memory	O
technologies	O
have	O
been	O
explored	O
with	O
the	O
goal	O
of	O
creating	O
a	O
practical	O
universal	B-Device
memory	I-Device
.	O
</s>
<s>
Since	O
each	O
memory	O
has	O
its	O
limitations	O
,	O
none	O
of	O
these	O
have	O
yet	O
reached	O
the	O
goals	O
of	O
universal	B-Device
memory	I-Device
.	O
</s>
