<s>
Decimal	B-Device
computers	I-Device
are	O
computers	O
which	O
can	O
represent	O
numbers	O
and	O
addresses	O
in	O
decimal	B-Application
as	O
well	O
as	O
providing	O
instructions	O
to	O
operate	O
on	O
those	O
numbers	O
and	O
addresses	O
directly	O
in	O
decimal	B-Application
,	O
without	O
conversion	O
to	O
a	O
pure	O
binary	O
representation	O
.	O
</s>
<s>
Early	O
computers	O
that	O
were	O
exclusively	O
decimal	B-Application
include	O
the	O
ENIAC	B-Device
,	O
IBM	B-Device
NORC	I-Device
,	O
IBM	B-Device
650	I-Device
,	O
IBM	B-Device
1620	I-Device
,	O
IBM	B-Device
7070	I-Device
,	O
UNIVAC	B-Device
Solid	I-Device
State	I-Device
80	I-Device
.	O
</s>
<s>
In	O
these	O
machines	O
,	O
the	O
basic	O
unit	O
of	O
data	O
was	O
the	O
decimal	B-Application
digit	O
,	O
encoded	O
in	O
one	O
of	O
several	O
schemes	O
,	O
including	O
binary-coded	O
decimal	B-Application
(	O
BCD	O
)	O
,	O
bi-quinary	B-Algorithm
and	O
two-out-of-five	O
code	O
.	O
</s>
<s>
Except	O
for	O
the	O
IBM	B-Device
1620	I-Device
and	O
1710	O
,	O
these	O
machines	O
used	O
word	B-General_Concept
addressing	I-General_Concept
.	O
</s>
<s>
When	O
non-numeric	O
characters	O
were	O
used	O
in	O
these	O
machines	O
,	O
they	O
were	O
encoded	O
as	O
two	O
decimal	B-Application
digits	O
.	O
</s>
<s>
Other	O
early	O
computers	O
were	O
character	O
oriented	O
,	O
providing	O
instructions	O
for	O
performing	O
arithmetic	O
on	O
character	O
strings	O
of	O
decimal	B-Application
numerals	O
,	O
using	O
BCD	O
or	O
excess-3	O
(	O
XS-3	O
)	O
for	O
decimal	B-Application
digits	O
.	O
</s>
<s>
UNIVAC	B-Operating_System
I	I-Operating_System
and	O
UNIVAC	B-Device
II	I-Device
used	O
word	B-General_Concept
addressing	I-General_Concept
,	O
with	O
12-character	O
words	O
.	O
</s>
<s>
IBM	O
examples	O
include	O
IBM	B-Device
702	I-Device
,	O
IBM	B-Device
705	I-Device
,	O
the	O
IBM	B-Device
1400	I-Device
series	I-Device
,	O
IBM	B-Device
7010	I-Device
,	O
and	O
the	O
IBM	B-Device
7080	I-Device
.	O
</s>
<s>
The	O
IBM	B-Application
System/360	I-Application
,	O
introduced	O
in	O
1964	O
to	O
unify	O
IBM	O
's	O
product	O
lines	O
,	O
used	O
per	O
character	O
binary	O
addressing	O
,	O
and	O
also	O
included	O
instructions	O
for	O
packed	O
decimal	B-Application
arithmetic	O
as	O
well	O
as	O
binary	O
integer	O
arithmetic	O
,	O
and	O
binary	O
floating	O
point	O
.	O
</s>
<s>
It	O
used	O
8-bit	O
characters	O
and	O
introduced	O
EBCDIC	B-Language
encoding	O
,	O
though	O
ASCII	B-Protocol
was	O
also	O
supported	O
.	O
</s>
<s>
The	O
Burroughs	B-Language
B2500	I-Language
introduced	O
in	O
1966	O
also	O
used	O
8-bit	O
EBCDIC	B-Language
or	O
ASCII	B-Protocol
characters	I-Protocol
and	O
could	O
pack	O
two	O
decimal	B-Application
digits	O
per	O
byte	O
,	O
but	O
it	O
did	O
not	O
provide	O
binary	O
arithmetic	O
,	O
making	O
it	O
a	O
decimal	B-Device
architecture	I-Device
.	O
</s>
<s>
Several	O
microprocessor	O
families	O
offer	O
limited	O
decimal	B-Application
support	O
.	O
</s>
<s>
The	O
x87	B-Application
FPU	I-Application
has	O
instructions	O
to	O
convert	O
10-byte	O
(	O
18	O
decimal	B-Application
digits	O
)	O
packed	O
decimal	B-Application
data	O
,	O
although	O
it	O
then	O
operates	O
on	O
them	O
as	O
floating-point	O
numbers	O
.	O
</s>
<s>
The	O
Motorola	B-Device
68000	I-Device
provided	O
instructions	O
for	O
BCD	O
addition	O
and	O
subtraction	O
;	O
as	O
does	O
the	O
6502	B-General_Concept
.	O
</s>
<s>
In	O
the	O
much	O
later	O
68000	B-Device
family-derived	O
processors	O
,	O
these	O
instructions	O
were	O
removed	O
when	O
the	O
Coldfire	B-Device
instruction	O
set	O
was	O
defined	O
,	O
and	O
all	O
IBM	O
mainframes	O
also	O
provide	O
BCD	O
integer	O
arithmetic	O
in	O
hardware	O
.	O
</s>
<s>
The	O
Zilog	B-General_Concept
Z80	I-General_Concept
,	O
Motorola	B-Device
6800	I-Device
and	O
its	O
derivatives	O
,	O
together	O
with	O
other	O
8-bit	O
processors	O
,	O
and	O
also	O
the	O
Intel	B-Operating_System
x86	I-Operating_System
family	O
have	O
special	O
instructions	O
that	O
support	O
conversion	O
to	O
and	O
from	O
BCD	O
.	O
</s>
<s>
The	O
Psion	B-Application
Organiser	I-Application
I	I-Application
handheld	O
computer	O
’s	O
manufacturer-supplied	O
software	O
implemented	O
its	O
floating	O
point	O
operations	O
in	O
software	O
using	O
BCD	O
entirely	O
.	O
</s>
<s>
Decimal	B-Application
arithmetic	O
is	O
now	O
becoming	O
more	O
common	O
;	O
for	O
instance	O
,	O
three	O
decimal	B-Application
types	O
with	O
two	O
binary	O
encodings	O
were	O
added	O
to	O
the	O
2008	O
IEEE	O
754r	O
standard	O
,	O
with	O
7-	O
,	O
16-	O
,	O
and	O
34-digit	O
decimal	B-Application
significands	B-Algorithm
.	O
</s>
<s>
The	O
IBM	O
Power6	O
processor	O
and	O
the	O
IBM	O
System	O
z9	O
have	O
implemented	O
these	O
types	O
using	O
the	O
Densely	O
Packed	O
Decimal	B-Application
binary	O
encoding	O
,	O
the	O
first	O
in	O
hardware	O
and	O
the	O
second	O
in	O
microcode	O
.	O
</s>
