<s>
Bi-quinary	B-Algorithm
coded	I-Algorithm
decimal	I-Algorithm
is	O
a	O
numeral	O
encoding	O
scheme	O
used	O
in	O
many	O
abacuses	O
and	O
in	O
some	O
early	O
computers	O
,	O
including	O
the	O
Colossus	B-Device
.	O
</s>
<s>
The	O
term	O
bi-quinary	B-Algorithm
indicates	O
that	O
the	O
code	O
comprises	O
both	O
a	O
two-state	O
(	O
bi	O
)	O
and	O
a	O
five-state	O
(	O
quinary	O
)	O
component	O
.	O
</s>
<s>
Several	O
human	O
languages	O
,	O
most	O
notably	O
Fula	O
and	O
Wolof	O
also	O
use	O
biquinary	B-Algorithm
systems	O
.	O
</s>
<s>
Roman	O
numerals	O
use	O
a	O
symbolic	O
,	O
rather	O
than	O
positional	O
,	O
bi-quinary	B-Algorithm
base	O
,	O
even	O
though	O
Latin	O
is	O
completely	O
decimal	O
.	O
</s>
<s>
The	O
Korean	O
finger	O
counting	O
system	O
Chisanbop	O
uses	O
a	O
bi-quinary	B-Algorithm
system	O
,	O
where	O
each	O
finger	O
represents	O
a	O
one	O
and	O
a	O
thumb	O
represents	O
a	O
five	O
,	O
allowing	O
one	O
to	O
count	O
from	O
0	O
to	O
99	O
with	O
two	O
hands	O
.	O
</s>
<s>
One	O
of	O
the	O
advantages	O
of	O
bi-quinary	B-Algorithm
encoding	O
on	O
digital	O
computers	O
is	O
that	O
it	O
must	O
have	O
2	O
bits	O
set	O
,	O
one	O
in	O
the	O
binary	O
field	O
and	O
one	O
in	O
the	O
quinary	O
field	O
,	O
and	O
thus	O
there	O
is	O
a	O
built	O
in	O
"	O
checksum	O
"	O
to	O
see	O
if	O
the	O
number	O
is	O
valid	O
or	O
not	O
.	O
</s>
<s>
Several	O
different	O
representations	O
of	O
bi-quinary	B-Algorithm
coded	I-Algorithm
decimal	I-Algorithm
have	O
been	O
used	O
by	O
different	O
machines	O
.	O
</s>
<s>
In	O
the	O
pictures	O
of	O
the	O
front	O
panel	O
below	O
and	O
in	O
close-up	O
,	O
the	O
bi-quinary	B-Algorithm
encoding	O
of	O
the	O
internal	O
workings	O
of	O
the	O
machine	O
are	O
evident	O
in	O
the	O
arrangement	O
of	O
the	O
lights	O
–	O
the	O
bi	O
bits	O
form	O
the	O
top	O
of	O
a	O
T	O
for	O
each	O
digit	O
,	O
and	O
the	O
quinary	O
bits	O
form	O
the	O
vertical	O
stem	O
.	O
</s>
