Control storeA control store is the part of a CPU's control unit that stores the CPU's microprogram. It is usually accessed by a microsequencer. A control store implementation whose contents are unalterable is known as a Read Only Memory (ROM) or Read Only Storage (ROS); one whose contents are alterable is known as a Writable Control Store (WCS). Early control stores were implemented as a diode-array accessed via address decoders, a form of read-only memory. This tradition dates back to the program timing matrix on the MIT Whirlwind, first described in 1947.
Microprocesseur à jeu d'instruction étenduUn microprocesseur à jeu d'instruction étendu (, CISC) désigne un microprocesseur possédant un jeu d'instructions comprenant de très nombreuses instructions . L'architecture CISC est opposée à l'architecture RISC qui au contraire, limite ses instructions à l'essentiel afin de réduire la quantité de transistors. Le premier microprocesseur est l'Intel 4004, d'architecture 4 bits, sorti en 1971, suivi de l'Intel 8008, d'architecture , sorti en 1972.
MicroVAXThe MicroVAX is a discontinued family of low-cost minicomputers developed and manufactured by Digital Equipment Corporation (DEC). The first model, the MicroVAX I, was introduced in 1983. They used processors that implemented the VAX instruction set architecture (ISA) and were succeeded by the VAX 4000. Many members of the MicroVAX family had corresponding VAXstation variants, which primarily differ by the addition of graphics hardware. The MicroVAX family supports Digital's VMS and ULTRIX operating systems.
IBM System/370The IBM System/370 (S/370) is a model range of IBM mainframe computers announced on June 30, 1970, as the successors to the System/360 family. The series mostly maintains backward compatibility with the S/360, allowing an easy migration path for customers; this, plus improved performance, were the dominant themes of the product announcement. In September 1990, the System/370 line was replaced with the System/390. The original System/370 line was announced on June 30, 1970, with first customer shipment of the Models 155 and 165 planned for February 1971 and April 1971 respectively.
Alpha 21064The Alpha 21064 is a microprocessor developed and fabricated by Digital Equipment Corporation that implemented the Alpha (introduced as the Alpha AXP) instruction set architecture (ISA). It was introduced as the DECchip 21064 before it was renamed in 1994. The 21064 is also known by its code name, EV4. It was announced in February 1992 with volume availability in September 1992. The 21064 was the first commercial implementation of the Alpha ISA, and the first microprocessor from Digital to be available commercially.
RSTSRSTS (Resource System Time Sharing) est un système d'exploitation propriétaire réalisé par Digital Equipment Corporation au début des années 1970 pour les machines de la série PDP-11. Larry Wall, le concepteur du langage de programmation Perl, a commencé sa carrière de programmeur sous RSTS. Il existe deux versions du système RSTS : le RSTS-11 et le RSTS/E. L'appellation RSTS-11 est un sigle pour désigner le système d'exploitation RSTS pour les machines PDP-11.
Bit slicingBit slicing is a technique for constructing a processor from modules of processors of smaller bit width, for the purpose of increasing the word length; in theory to make an arbitrary n-bit central processing unit (CPU). Each of these component modules processes one bit field or "slice" of an operand. The grouped processing components would then have the capability to process the chosen full word-length of a given software design. Bit slicing more or less died out due to the advent of the microprocessor.
DecnetDECnet est une architecture réseau en couches, sur un protocole défini par Digital Equipment Corporation. Les plus malicieux disent "Do Expect Cuts" (attendez-vous à des coupures). DECnet est aussi un groupe de produits de communications de données comportant une suite de protocoles développée et soutenue par Digital Equipment Corporation (Digital). La première version de DECnet, 1975, a permis à deux mini-ordinateurs PDP-11 de communiquer conjointement.
Page replacement algorithmIn a computer operating system that uses paging for virtual memory management, page replacement algorithms decide which memory pages to page out, sometimes called swap out, or write to disk, when a page of memory needs to be allocated. Page replacement happens when a requested page is not in memory (page fault) and a free page cannot be used to satisfy the allocation, either because there are none, or because the number of free pages is lower than some threshold.
