<s>
The	O
HP-12C	B-Device
is	O
a	O
financial	B-General_Concept
calculator	I-General_Concept
made	O
by	O
Hewlett-Packard	O
(	O
HP	O
)	O
and	O
its	O
successor	O
HP	O
Inc	O
.	O
as	O
part	O
of	O
the	O
HP	B-Device
Voyager	I-Device
series	I-Device
,	O
introduced	O
in	O
1981	O
.	O
</s>
<s>
It	O
's	O
HP	O
's	O
longest	O
and	O
best-selling	O
product	O
and	O
is	O
considered	O
the	O
de	O
facto	O
standard	O
among	O
financial	B-General_Concept
professionals	O
.	O
</s>
<s>
The	O
HP-12C	B-Device
is	O
HP	O
's	O
longest	O
and	O
best-selling	O
product	O
,	O
in	O
continual	O
production	O
since	O
its	O
introduction	O
in	O
1981	O
.	O
</s>
<s>
Due	O
to	O
its	O
simple	O
operation	O
for	O
key	O
financial	B-General_Concept
calculations	O
,	O
the	O
calculator	B-Application
long	O
ago	O
became	O
the	O
de	O
facto	O
standard	O
among	O
financial	B-General_Concept
professionals	O
.	O
</s>
<s>
Its	O
popularity	O
has	O
endured	O
despite	O
a	O
relatively	O
simple	O
but	O
iterative	O
process	O
such	O
as	O
amortizing	O
the	O
interest	O
over	O
the	O
life	O
of	O
a	O
loan	O
,	O
a	O
calculation	O
that	O
modern	O
spreadsheets	B-Application
can	O
complete	O
almost	O
instantly	O
,	O
can	O
take	O
over	O
a	O
minute	O
with	O
the	O
HP-12C	B-Device
.	O
</s>
<s>
The	O
1977	O
October	O
edition	O
of	O
the	O
HP	O
Journal	O
contains	O
an	O
article	O
by	O
Roy	O
Martin	O
,	O
the	O
inventor	O
of	O
the	O
simple	O
method	O
of	O
operation	O
used	O
in	O
HP	O
financial	B-General_Concept
calculators	I-General_Concept
,	O
which	O
describes	O
,	O
in	O
detail	O
,	O
the	O
mathematics	O
and	O
functionality	O
built	O
by	O
William	O
Kahan	O
and	O
Roy	O
Martin	O
that	O
is	O
still	O
used	O
today	O
.	O
</s>
<s>
There	O
were	O
at	O
least	O
eight	O
hardware	O
revisions	O
of	O
the	O
HP-12C	B-Device
since	O
1981	O
(	O
including	O
one	O
special	O
issue	O
)	O
.	O
</s>
<s>
Over	O
its	O
lifespan	O
,	O
the	O
proprietary	O
CMOS	B-Device
HP	O
Nut	O
(	O
originally	O
the	O
1LF5	O
,	O
then	O
1LM2	O
)	O
processor	O
's	O
technology	O
has	O
been	O
redesigned	O
to	O
integrate	O
all	O
the	O
circuitry	O
into	O
a	O
single	O
chip	O
(	O
first	O
the	O
1LQ9	O
,	O
then	O
1RR2	O
)	O
and	O
to	O
refresh	O
the	O
manufacturing	O
process	O
(	O
as	O
the	O
foundry	O
could	O
no	O
longer	O
manufacture	O
the	O
necessary	O
chips	O
,	O
having	O
moved	O
on	O
to	O
making	O
higher-density	O
chips	O
)	O
.	O
</s>
<s>
In	O
2001	O
(	O
from	O
serial	O
number	O
CN11500001	O
)	O
,	O
the	O
CPU	O
was	O
changed	O
to	O
a	O
3V	O
process	O
(	O
Agilent	O
2AF1-0001	O
,	O
later	O
a	O
Marvell	O
2AF1-0002	O
)	O
and	O
the	O
battery	O
was	O
therefore	O
changed	O
to	O
a	O
single	O
CR2032	B-Algorithm
cell	O
replacing	O
the	O
three	O
LR44	B-Algorithm
cells	O
previously	O
used	O
(	O
F1637A	O
)	O
.	O
</s>
<s>
HP	O
also	O
released	O
a	O
software	B-Application
development	I-Application
kit	I-Application
(	O
SDK	O
)	O
,	O
making	O
it	O
possible	O
to	O
make	O
new	O
and	O
custom	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
The	O
calculator	B-Application
ran	O
60-90	O
times	O
faster	O
on	O
most	O
benchmark	O
operations	O
.	O
</s>
<s>
This	O
version	O
(	O
F2230A	O
)	O
was	O
colloquially	O
known	O
as	O
the	O
"	O
HP-12C	B-Device
+	O
"	O
,	O
although	O
HP	O
did	O
not	O
market	O
it	O
as	O
a	O
different	O
product	O
.	O
</s>
<s>
In	O
contrast	O
to	O
the	O
preceding	O
revision	O
,	O
it	O
supported	O
two	O
parallel	O
CR2032	B-Algorithm
cells	O
,	O
of	O
which	O
only	O
one	O
was	O
necessary	O
to	O
run	O
the	O
calculator	B-Application
.	O
</s>
<s>
The	O
internal	O
hardware	O
of	O
the	O
HP-12C	B-Device
changed	O
again	O
in	O
2015	O
,	O
when	O
the	O
design	O
switched	O
to	O
use	O
an	O
Atmel	O
ATSAM4LC2CA-AU	O
processor	O
with	O
ARM	O
Cortex-M4	O
core	O
.	O
</s>
<s>
The	O
calculator	B-Application
's	O
part	O
number	O
and	O
physical	O
appearance	O
did	O
n't	O
change	O
except	O
for	O
a	O
"	O
Rev	O
2	O
"	O
plate	O
on	O
the	O
bottom	O
side	O
.	O
</s>
<s>
It	O
continues	O
to	O
use	O
two	O
parallel	O
CR2032	B-Algorithm
cells	O
.	O
</s>
<s>
The	O
2×	O
3-pin	O
flash	O
port	O
now	O
uses	O
the	O
USB	B-Protocol
protocol	O
instead	O
of	O
a	O
TTL	O
serial	O
protocol	O
;	O
in	O
addition	O
to	O
this	O
,	O
the	O
calculator	B-Application
's	O
circuit	O
board	O
features	O
an	O
unpopulated	O
mount	O
for	O
a	O
Micro-USB	O
connector	O
.	O
</s>
<s>
The	O
HP-12C	B-Device
is	O
one	O
of	O
only	O
four	O
calculators	B-Application
permissible	O
in	O
the	O
Chartered	O
Financial	B-General_Concept
Analyst	O
exams	O
,	O
the	O
others	O
being	O
its	O
sister	O
,	O
the	O
HP	O
12c	O
Platinum	O
,	O
and	O
the	O
Texas	O
Instruments	O
BA	B-Application
II	I-Application
Plus	I-Application
and	I-Application
BA	I-Application
II	I-Application
Plus	I-Application
Professional	I-Application
.	O
</s>
<s>
Often	O
referred	O
to	O
as	O
a	O
tool	O
for	O
"	O
Old-ie	O
Time-ies	O
,	O
"	O
critics	O
of	O
the	O
HP-12C	B-Device
claim	O
its	O
early	O
1980s	O
technology	O
and	O
style	O
are	O
antiquated	O
.	O
</s>
<s>
Proponents	O
,	O
however	O
,	O
are	O
quick	O
to	O
note	O
that	O
the	O
HP-12C	B-Device
continues	O
to	O
be	O
both	O
the	O
de	O
jure	O
and	O
de	O
facto	O
standard	O
of	O
high	O
finance	O
.	O
</s>
<s>
The	O
calculator	B-Application
was	O
introduced	O
in	O
2003	O
,	O
is	O
visibly	O
distinguished	O
by	O
its	O
silver-colored	O
upper	O
half	O
as	O
opposed	O
to	O
the	O
gold-colored	O
plate	O
on	O
the	O
original	O
12c	O
.	O
</s>
<s>
The	O
12c	O
Platinum	O
has	O
a	O
faster	O
processor	O
(	O
originally	O
a	O
Sunplus	B-Device
SPLB20D2	I-Device
with	O
6502	B-General_Concept
core	O
)	O
,	O
larger	O
memory	O
(	O
for	O
up	O
to	O
30	O
CFj	O
registers	O
and	O
400	O
program	O
steps	O
)	O
and	O
more	O
built-in	O
functions	O
.	O
</s>
<s>
The	O
calculator	B-Application
's	O
particular	O
implementation	O
of	O
RPN	O
exhibits	O
an	O
unusual	O
behaviour	O
of	O
the	O
key	O
different	O
from	O
that	O
of	O
the	O
12C	O
and	O
other	O
classical	O
RPN	O
calculators	B-Application
.	O
</s>
<s>
The	O
firmware	O
changes	O
increased	O
the	O
ROM	O
size	O
beyond	O
the	O
capabilities	O
of	O
the	O
original	O
processor	O
,	O
so	O
it	O
was	O
replaced	O
by	O
the	O
Generalplus	O
GPLB31A	O
(	O
still	O
with	O
6502	B-General_Concept
core	O
)	O
,	O
which	O
is	O
also	O
faster	O
.	O
</s>
<s>
As	O
in	O
the	O
later	O
revisions	O
of	O
the	O
12C	O
,	O
it	O
features	O
two	O
parallel	O
rather	O
than	O
only	O
one	O
CR2032	B-Algorithm
cells	O
,	O
but	O
it	O
continues	O
to	O
be	O
based	O
on	O
the	O
GPLB31A	O
processor	O
.	O
</s>
<s>
By	O
design	O
,	O
the	O
HP-12C	B-Device
rounds	O
up	O
the	O
number	O
of	O
payments	O
to	O
the	O
next	O
integer	O
,	O
which	O
produces	O
meaningless	O
results	O
when	O
calculating	O
fractional	O
periods	O
.	O
</s>
<s>
Consequently	O
,	O
solving	O
for	O
n	O
returns	O
a	O
value	O
that	O
is	O
mathematically	O
incorrect	O
vis-a-vis	O
the	O
standard	O
annuity	O
formula	O
and	O
different	O
from	O
the	O
value	O
returned	O
by	O
other	O
financial	B-General_Concept
calculators	I-General_Concept
,	O
Excel	O
,	O
etc	O
.	O
</s>
<s>
The	O
Aurora	O
FN1000	O
calculator	B-Application
in	O
clamshell	O
design	O
was	O
closely	O
inspired	O
by	O
the	O
HP-12C	B-Device
in	O
2003	O
.	O
</s>
<s>
It	O
closely	O
emulates	O
the	O
functionality	O
of	O
the	O
original	O
HP-12C	B-Device
by	O
running	O
the	O
original	O
ROM	O
image	O
in	O
an	O
emulator	O
on	O
an	O
ARM	O
Cortex-M0-based	O
NXP	O
LPC1114	O
processor	O
.	O
</s>
<s>
In	O
February	O
2016	O
,	O
SwissMicros	O
introduced	O
the	O
DM12L	O
,	O
a	O
version	O
of	O
the	O
calculator	B-Application
about	O
the	O
same	O
size	O
as	O
the	O
original	O
HP-12C	B-Device
.	O
</s>
<s>
Deviating	O
from	O
the	O
HP	O
original	O
,	O
these	O
calculators	B-Application
feature	O
a	O
dot-matrix	O
display	O
,	O
switchable	O
fonts	O
and	O
clock	O
speeds	O
,	O
and	O
,	O
based	O
on	O
a	O
Silicon	O
Labs	O
CP2102	O
converter	O
chip	O
,	O
they	O
come	O
with	O
a	O
USB	B-Protocol
(	O
Mini-B	O
)	O
serial	O
interface	O
to	O
exchange	O
data	O
with	O
a	O
PC	O
etc	O
.	O
</s>
<s>
for	O
backup	O
purposes	O
(	O
and	O
possibly	O
to	O
communicate	O
with	O
applications	O
like	O
PC-based	O
HP-12C	B-Device
emulators	O
)	O
or	O
to	O
update	O
the	O
firmware	O
.	O
</s>
<s>
Powering	O
via	O
USB	B-Protocol
is	O
not	O
supported	O
.	O
</s>
