This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages)(Learn how and when to remove this template message)
In computer architecture, 12-bit integers, memory addresses, or other data units are those that are 12 bits (1.5 octets) wide. Also, 12-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size.
Possibly the best-known 12-bit CPU is the PDP-8 and its relatives, such as the Intersil 6100 microprocessor produced in various incarnations from August 1963 to mid-1990. Many analog to digital converters (ADCs) have a 12-bit resolution. Some PIC microcontrollers use a 12-bit word size.
12 binary digits, or 3 nibbles (a 'tribble'), have 4096 (10000 octal, 1000 hexadecimal) distinct combinations. Hence, a microprocessor with 12-bit memory addresses can directly access 4096 words (4 Kw) of word-addressable memory. At a time when six-bit character codes were common a 12-bit word, which could hold two characters, was a convenient size. IBM System/360 instruction formats use a 12-bit displacement field which, added to the contents of a base register, can address 4096 bytes of memory.
List of 12-bit computer systemsEdit
- Digital Equipment Corporation
- Ford EEC I automotive engine control unit
- Intersil IM6100 microprocessor (PDP-8-compatible)
- Control Data Corporation
- National Cash Register NCR 315
- Scientific Data Systems SDS 92
- PC12 minicomputer
- Ferranti Argus
- LINC, later commercialized by DEC as the LINC-8
- Electronic Arrays 9002 (12-bit addressing but 8-bit byte)
- "1973: 12-bit engine-control microprocessor (Toshiba)" (PDF). Semiconductor History Museum of Japan. Retrieved 27 June 2019.
|This computer hardware article is a stub. You can help Wikipedia by expanding it.|