<s>
The	O
term	O
continuous	B-Device
memory	I-Device
was	O
coined	O
by	O
Hewlett-Packard	O
(	O
HP	O
)	O
to	O
describe	O
a	O
unique	O
feature	O
of	O
certain	O
HP	B-Device
calculators	I-Device
whereby	O
the	O
calculator	O
could	O
internally	O
sustain	O
most	O
,	O
or	O
in	O
later	O
models	O
-	O
all	O
,	O
of	O
the	O
contents	O
of	O
user	O
memory	O
(	O
via	O
battery-backed	O
CMOS	B-Device
memory	I-Device
)	O
.	O
</s>
<s>
Since	O
its	O
introduction	O
on	O
the	O
HP-25C	B-Device
,	O
this	O
feature	O
slowly	O
evolved	O
by	O
model	O
to	O
eventually	O
mean	O
maintaining	O
the	O
contents	O
of	O
nearly	O
all	O
calculator	O
memory	O
,	O
including	O
system	O
and	O
scratch	O
RAM	B-Architecture
,	O
options	O
,	O
settings	O
,	O
flags	O
,	O
and	O
other	O
calculator	O
state	O
information	O
.	O
</s>
<s>
Before	O
the	O
introduction	O
of	O
the	O
HP-25C	B-Device
in	O
1976	O
,	O
all	O
calculator	O
random-access	B-Architecture
memory	I-Architecture
(	O
RAM	B-Architecture
)	O
was	O
volatile	O
,	O
i.e.	O
</s>
<s>
Three	O
early	O
models	O
with	O
this	O
improved	O
,	O
continuous	B-Device
memory	I-Device
-	O
the	O
HP-25C	B-Device
,	O
HP-29C	B-Device
,	O
and	O
HP-19C	B-Device
-	O
actually	O
had	O
the	O
words	O
"	O
Continuous	B-Device
Memory	I-Device
"	O
printed	O
in	O
conspicuous	O
,	O
white	O
script	O
on	O
the	O
bottom	O
margin	O
of	O
their	O
faceplates	O
.	O
</s>
<s>
HP	O
did	O
not	O
print	O
this	O
phrase	O
on	O
subsequent	O
,	O
featured	O
models	O
because	O
the	O
novelty	O
of	O
continuous	B-Device
memory	I-Device
had	O
by	O
then	O
faded	O
and	O
also	O
because	O
it	O
could	O
no	O
longer	O
claim	O
it	O
as	O
a	O
feature	O
unique	O
to	O
HP	B-Device
calculators	I-Device
(	O
Texas	O
Instruments	O
would	O
later	O
call	O
their	O
identical	O
feature	O
"	O
Constant	O
Memory	O
"	O
)	O
.	O
</s>
<s>
the	O
HP-34C	B-Device
and	O
the	O
Voyager	B-Device
series	I-Device
HP-10C	B-Device
,	O
HP-11C	B-Device
,	O
HP-12C	B-Device
,	O
HP-15C	B-Device
and	O
HP-16C	B-Device
.	O
</s>
