Bi-quinary coded decimal is a numeral encoding scheme used in many

abacus The abacus (''plural'' abaci or abacuses), also called a counting frame, is a calculating tool which has been used since ancient times. It was used in the ancient Near East, Europe, China, and Russia, centuries before the adoption of the H ...

es and in some early computers, including the

Colossus Colossus, Colossos, or the plural Colossi or Colossuses, may refer to: Statues * Any exceptionally large statue ** List of tallest statues ** :Colossal statues * '' Colossus of Barletta'', a bronze statue of an unidentified Roman emperor * '' C ...

. The term ''bi-quinary'' indicates that the code comprises both a two-state (''bi'') and a five-state (''quin''ary) component. The encoding resembles that used by many abacuses, with four beads indicating either 0 through 4 or 5 through 9 and another bead indicating which of those ranges. Several human languages, most notably Fula and Wolof also use biquinary systems. For example, the Fula word for 6, ''jowi e go'o'', literally means ''five lusone''. Roman numerals use a symbolic, rather than positional, bi-quinary base, even though

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

is completely decimal.

Examples

Several different representations of bi-quinary coded decimal have been used by different machines. The two-state component is encoded as one or two

bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented a ...

s, and the five-state component is encoded using three to five bits. Some examples are: * Roman and Chinese

es * Stibitz relay calculators at Bell Labs from Model II onwards * FACOM 128 relay calculators at

Fujitsu is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the la ...

IBM 650 The IBM 650 Magnetic Drum Data-Processing Machine is an early digital computer produced by IBM in the mid-1950s. It was the first mass produced computer in the world. Almost 2,000 systems were produced, the last in 1962, and it was the firs ...

– seven 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 is set in a valid digit. In the pictures of the front panel below and in close-up, the bi-quinary encoding of the internal workings of the machine are evident in the arrangement of the lights – the ''bi'' bits form the top of a T for each digit, and the ''quinary'' bits form the vertical stem. : (the machine was running when the photograph was taken and the active bits are visible in the close-up and just discernible in the full panel picture) *

Remington Rand 409 The Remington Rand 409, a punched card calculator which was programmed with a plugboard, was designed designed in 1949. It was sold in two models: the UNIVAC 60 (1952) and the UNIVAC 120 (1953). The model number referred to the number of decimal ...

- five bits :One ''quinary'' bit (tube) for each of 1, 3, 5, and 7 - only one of these would be on at the time. :The fifth ''bi'' bit represented 9 if none of the others were on; otherwise it added 1 to the value represented by the other ''quinary'' bit. :(sold in the two models

UNIVAC 60 60 may refer to: * 60 (number) * one of the years 60 BC, AD 60, 1960, 2060 * Neodymium, the 60th element * <, the ASCII character with code 60 *

UNIVAC 120 120 may refer to: *120 (number), the number * AD 120, a year in the 2nd century AD *120 BC, a year in the 2nd century BC *120 film, a film format for still photography * ''120'' (film), a 2008 film *120 (MBTA bus) *120 (New Jersey bus) *120 (Kent) ...

) *

UNIVAC Solid State The UNIVAC Solid State was a magnetic drum-based solid-state computer announced by Sperry Rand in December 1958 as a response to the IBM 650. It was one of the first computers to be (nearly) entirely solid-state, using 700 transistors, and 3000 m ...

– four bits :One ''bi'' bit: 5, three binary coded ''quinary'' bits: 4 2 1 and one parity check bit *

UNIVAC LARC The UNIVAC LARC, short for the ''Livermore Advanced Research Computer'', is a mainframe computer designed to a requirement published by Edward Teller in order to run hydrodynamic simulations for nuclear weapon design. It was one of the earlie ...

– four bits :One ''bi'' bit: 5, three

Johnson counter A ring counter is a type of counter composed of flip-flops connected into a shift register, with the output of the last flip-flop fed to the input of the first, making a "circular" or "ring" structure. There are two types of ring counters: * A s ...

-coded ''quinary'' bits and one parity check bit

Examples

See also

References

Further reading