Before the widespread adoption of

ASCII ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control c ...

in the late 1960s,

six-bit character code A six-bit character code is a character encoding designed for use on computers with word lengths a multiple of 6. Six bits can only encode 64 distinct characters, so these codes generally include only the upper-case letters, the numerals, some pun ...

s were common and a 12-bit word, which could hold two characters, was a convenient size. This also made it useful for storing a single decimal digit along with a sign. Possibly the best-known 12-bit CPUs are the

PDP-8 The PDP-8 is a family of 12-bit minicomputers that was produced by Digital Equipment Corporation (DEC). It was the first commercially successful minicomputer, with over 50,000 units sold during the model's lifetime. Its basic design follows the pi ...

and its descendants (such as the Intersil 6100 microprocessor), which were produced in various forms from August 1963 to mid-1990. Many analog to digital converters (ADCs) have a 12-bit resolution. Some

PIC microcontroller PIC (usually pronounced as /pɪk/) is a family of microcontrollers made by Microchip Technology, derived from the PIC1640 originally developed by General Instrument's Microelectronics Division. The name PIC initially referred to ''Peripher ...

s use a 12-bit instruction word but handle only 8-bit data. 12 binary digits, or 3 nibbles (a 'tribble'), have 4096 (10000

octal Octal (base 8) is a numeral system with eight as the base. In the decimal system, each place is a power of ten. For example: : \mathbf_ = \mathbf \times 10^1 + \mathbf \times 10^0 In the octal system, each place is a power of eight. For ex ...

, 1000

hexadecimal Hexadecimal (also known as base-16 or simply hex) is a Numeral system#Positional systems in detail, positional numeral system that represents numbers using a radix (base) of sixteen. Unlike the decimal system representing numbers using ten symbo ...

) distinct combinations. Hence, a microprocessor with 12-bit memory addresses can directly access 4096

words A word is a basic element of language that carries meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no consensus among linguists on its ...

(4 kW) of

word-addressable In computer architecture, ''word addressing'' means that addresses of memory on a computer uniquely identify words of memory. It is usually used in contrast with byte addressing, where addresses uniquely identify bytes. Almost all modern compu ...

memory. IBM

System/360 The IBM System/360 (S/360) is a family of mainframe computer systems announced by IBM on April 7, 1964, and delivered between 1965 and 1978. System/360 was the first family of computers designed to cover both commercial and scientific applicati ...

instruction formats use a 12-bit displacement field which, added to the contents of a base register, can address 4096 bytes of memory in a region that begins at the address in the base register.

List of 12-bit computer systems

Digital Equipment Corporation Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president until ...

PDP-5 The PDP-5 was Digital Equipment Corporation's first 12-bit computer, introduced in 1963. History An earlier 12-bit computer, named LINC has been described as the first minicomputer and also "the first modern personal computer." It had 2,048 1 ...

***

DECmate DECmate was the name of a series of PDP-8-compatible computers produced by the Digital Equipment Corporation in the late 1970s and early 1980s. All of the models used an Intersil 6100 (later known as the Harris 6100) or Harris 6120 (an improved ...

, a personal computer based on the Intersil 6100 ** PDP-12 ** PDP-14 * Ford EEC I automotive engine control unit ** Toshiba TLCS-12 microprocessor *

Intersil Intersil is an American semiconductor company headquartered in Milpitas, California. , Intersil is a subsidiary of Renesas. The previous Intersil was formed in August 1999 through the acquisition of the semiconductor business of Harris Corpor ...

IM6100 microprocessor (PDP-8-compatible) *

Control Data Corporation Control Data Corporation (CDC) was a mainframe and supercomputer company that in the 1960s was one of the nine major U.S. computer companies, which group included IBM, the Burroughs Corporation, and the Digital Equipment Corporation (DEC), the N ...

CDC 160 series The CDC 160 series was a series of minicomputers built by Control Data Corporation. The CDC 160 and CDC 160-A were 12-bit minicomputers built from 1960 to 1965; the CDC 160G was a 13-bit minicomputer, with an extended version of the CDC 160-A in ...

computers **

CDC 6600 The CDC 6600 was the flagship of the 6000 series of mainframe computer systems manufactured by Control Data Corporation. Generally considered to be the first successful supercomputer, it outperformed the industry's prior recordholder, the I ...

- Peripheral Processor (PP) *

National Cash Register NCR Voyix Corporation, previously known as NCR Corporation and National Cash Register, is a global software, consulting and technology company providing several professional services and electronic products. It manufactured self-service kios ...

NCR 315 The NCR 315 Data Processing System, released in January 1962 by NCR, is a second-generation computer. All printed circuit boards use resistor–transistor logic (RTL) to create the various logic elements. It uses 12-bit ''slab'' memory struct ...

Scientific Data Systems Scientific Data Systems (SDS), was an American computer company founded in September 1961 by Max Palevsky, Arthur Rock and Robert Beck, veterans of Packard Bell Corporation and Bendix, along with eleven other computer scientists. SDS was the f ...

SDS 92 * Nuclear Data, Inc.

ND812 The 12-bit ND812, produced by Nuclear Data, Inc., was a commercial minicomputer developed for the scientific computing market. Nuclear Data introduced it in 1970 at a price under $10,000 (). Description The architecture has a simple programmed ...

PC12 minicomputer PC12 by Artronix was a minicomputer built with 7400-series integrated circuits, 7400-series TTL technology and Ferrite (magnet), ferrite core memory. Computers were manufactured at the Artronix facility in suburban St. Louis, Missouri. The instru ...

Ferranti Argus Ferranti's Argus computers were a line of industrial control computers offered from the 1960s into the 1980s. Originally designed for a military role, a re-packaged Argus was the first digital computer to be used to directly control an entire fact ...

LINC The LINC (Laboratory INstrument Computer) is a 12-bit, 2048-word transistorized computer. The LINC is considered by some to be the first minicomputer and a forerunner to the personal computer. Originally named the Linc, suggesting the project' ...

, later commercialized by DEC as the LINC-8

References

External links

DIGITAL Computing Timeline: 12-bit architecture
Computer data {{computer-hardware-stub

List of 12-bit computer systems

See also

References

External links