Bi-quinary coded decimal

Bi-quinary coded decimal is a numeral system used in many abacuses and in some early computers, including the Colossus_computer. The term ''bi-quinary'' indicates that the code comprises both a two-state (''bi'') and a five-state (''quin''ary) component. Several different representations of bi-quinary coded decimal have been used by different machines. The two-state component is encoded as one or two bits, and the five-state component is encoded using three or five bits. Some examples are: *IBM 650 – 7 bits (two ‘bi’ bits: 0 5 and five ‘quinary’ bits: 0 1 2 3 4) with error checking (exactly one ‘bi’ bit and one ‘quinary’ bit set in a valid digit); in the picture of the front panel below, the bi-quinary encoding of the internal workings of the machine are evident in the arrangement of the lights (active bits are just visible)

Value	05-01234 Bits	IBM 650 front panel
0	10-10000
1	10-01000
2	10-00100
3	10-00010
4	10-00001
5	01-10000
6	01-01000
7	01-00100
8	01-00010
9	01-00001

*UNIVAC Solid State – 4 bits (one ‘bi’ bit: 5 and three binary coded ‘quinary’ bits: 4 2 1) with 1 parity bit

Value	p-5-421 bits
0	1-0-000
1	0-0-001
2	0-0-010
3	1-0-011
4	0-0-100
5	0-1-000
6	1-1-001
7	1-1-010
8	0-1-011
9	1-1-100

*Univac LARC – 4 bits (one ‘bi’ bit: 5 and three ring counter coded ‘quinary’ bits) with 1 parity check bit

Value	p-5-qqq bits
0	1-0-000
1	0-0-001
2	1-0-011
3	0-0-111
4	1-0-110
5	0-1-000
6	1-1-001
7	0-1-011
8	1-1-111
9	0-1-110

== See also == *Binary numeral system *Binary-coded decimal Numeration Computer arithmetic

See other meanings of words starting from letter:

B

BA | BC | BD | BE | BF | BG | BH | BI | BJ | BK | BL | BM | BN | BO | BP | BR | BS | BT | BU | BW | BX | BY | BZ |

Words begining with Bi-quinary_coded_decimal:

Bi-quinary_coded_decimal