Hollerith code
Encyclopedia
Hollerith Code is the 12-bit code used on a punched-card.
In 1896, Herman Hollerith
(1860–1929) formed a company called the Tabulating Machine Company. This company developed a line of machines that used punched card
s for tabulation. After a number of mergers, the Tabulating Machine Company was formed into the International Business Machines Corporation, now referred to more commonly as IBM
, Inc. We often refer to the punched-cards used in computer systems as Hollerith cards in honor of Herman Hollerith.
A Hollerith string is a sequence of 12-bit characters; they are encoded as two ASCII
characters, containing 6 bits each: the first character contains punches 12, 0, 2, 4, 6, 8 and the second character contains punches 11, 1, 3, 5, 7, 9; interleaving the two characters gives the original 12 bits. To make the characters printable on ASCII terminals, bit 7 is always set to 0, and bit 6 is set to the complement of bit 5. These two bits are ignored when reading Hollerith cards.
A device for translating a multi-bit input code into a desired multi-bit output code including a double-ended decoding circuit which converts the signals representing an input character into a single signal and apparatus which encodes this single signal into the signals representing a corresponding output character.
alphanumeric code
:
Simply a code that uses both letters of the alphabet and numbers.
12-bit:
In binary
(base 2) only 0 and 1 are used as count weight. Decimal (base 10) numbers 0 through 9 are used.
A 12 bit decimal number is 100 000 000 000 and is read 100 Giga or one hundred thousand million.
In binary 12 bit is 1000000000 and each place is a power of 2 so this number is 2^10 = 1024 decimal.
In 1896, Herman Hollerith
Herman Hollerith
Herman Hollerith was an American statistician who developed a mechanical tabulator based on punched cards to rapidly tabulate statistics from millions of pieces of data. He was the founder of one of the companies that later merged and became IBM.-Personal life:Hollerith was born in Buffalo, New...
(1860–1929) formed a company called the Tabulating Machine Company. This company developed a line of machines that used punched card
Punched card
A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...
s for tabulation. After a number of mergers, the Tabulating Machine Company was formed into the International Business Machines Corporation, now referred to more commonly as IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
, Inc. We often refer to the punched-cards used in computer systems as Hollerith cards in honor of Herman Hollerith.
A Hollerith string is a sequence of 12-bit characters; they are encoded as two ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
characters, containing 6 bits each: the first character contains punches 12, 0, 2, 4, 6, 8 and the second character contains punches 11, 1, 3, 5, 7, 9; interleaving the two characters gives the original 12 bits. To make the characters printable on ASCII terminals, bit 7 is always set to 0, and bit 6 is set to the complement of bit 5. These two bits are ignored when reading Hollerith cards.
A device for translating a multi-bit input code into a desired multi-bit output code including a double-ended decoding circuit which converts the signals representing an input character into a single signal and apparatus which encodes this single signal into the signals representing a corresponding output character.
alphanumeric code
Alphanumeric code
In general, in computing, an alphanumeric code is a series of letters and numbers which are written in a form that can be processed by a computer....
:
Simply a code that uses both letters of the alphabet and numbers.
12-bit:
In binary
Binary
- Mathematics :* Binary numeral system, a representation for numbers using only two digits * Binary function, a function in mathematics that takes two arguments- Computing :* Binary file, composed of something other than human-readable text...
(base 2) only 0 and 1 are used as count weight. Decimal (base 10) numbers 0 through 9 are used.
A 12 bit decimal number is 100 000 000 000 and is read 100 Giga or one hundred thousand million.
In binary 12 bit is 1000000000 and each place is a power of 2 so this number is 2^10 = 1024 decimal.