|
VAXBI
VAXBI (VAX Bus Interconnect) is a computer bus designed and sold by Digital Equipment Corporation (DEC), introduced in 1986. The bus is an advanced, configuration-free synchronous bus used on DEC's later VAX computers. Like the Unibus and Q-Bus before it, it uses memory-mapped I/O but has 32-bit address and data paths. The VAXBI is a multiplexed bus with fully distributed arbitration and geographic addressing. All of the logic required to implement a VAXBI interface is contained within a single custom integrated circuit (the "BIIC") and the physical layout and printed wiring board layout for compliant cards is tightly specified, right down to the location of the dual amber status LEDs that are required. The portion of the card that is reserved for the bus interface is referred to as "the VAXBI corner". VAXBI licensees were given the appropriate engineering drawings to allow them to exactly replicate a compliant card. VAXBI expansion cards mount into backplanes using a ZIF co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VAX 8000
The VAX 8000 is a discontinued family of superminicomputers developed and manufactured by Digital Equipment Corporation (DEC) using processors implementing the VAX instruction set architecture (ISA). The 8000 series was introduced in October 1984 with the 8600, taking over the high end of the VAX lineup. Originally known as the 11/790, it offers performance roughly four times that of the earlier 11/780. It was succeeded by the 8650 (formerly the 11/795) in December 1985. January 1986 saw the introduction of the 8200 and 8300 families in the mid-range. The 8800 replaced the 8600s at the high end in 1987, with the 8700 and 8500 being lower-performance versions of these systems. DEC also offered various clusters of these machines with a variety of model numbers. As with other VAX systems, they were sold with either the VMS or Ultrix operating systems. It was intended that the 8800 was to have been replaced by the VAX 9000 on the high end, but this project failed. Instead, the VAX ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VAX 6000
The VAX 6000 is a discontinued family of minicomputers developed and manufactured by Digital Equipment Corporation (DEC) using processors implementing the VAX instruction set architecture (ISA). Originally, the VAX 6000 was intended to be a mid-range VAX product line complementing the VAX 8000, but with the introduction of the VAX 6000 Model 400 series, the older VAX 8000 was discontinued in favor of the VAX 6000, which offered slightly higher performance for half the cost. The VAX 6000 family supports Digital's OpenVMS, VMS and ULTRIX operating systems. Cabinet The VAX 6000 was housed in a cabinet which contained three card cages in the upper portion: a 14-slot XMI card cage on the right for CPU and memory modules, and optional VAXBI Bus hardware on the left. The VAXBI hardware distinguished two versions of the VAX 6000 platform, XMI-1 and XMI-2. XMI-1 differed from XMI-2 by requiring a DWMBA adapter and the presence of two 6-slot VAXBI channels, whereas in the XMI-2 platform, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VAX 9000
The VAX 9000 is a discontinued family of mainframes developed and manufactured by Digital Equipment Corporation (DEC) using custom ECL-based processors implementing the VAX instruction set architecture (ISA). Equipped with optional vector processors, they were marketed into the supercomputer space as well. As with other VAX systems, they were sold with either the VMS or Ultrix operating systems. The systems trace their history to DEC's 1984 licensing of several technologies from Trilogy Systems, who had introduced a new way to densely pack ECL chips into complex modules. Development of the 9000 design began in 1986, intended as a replacement for the VAX 8800 family, at that time the high-end VAX offering. The initial plans called for two general models, the high-performance ''Aquarius'' using water cooling as seen on IBM systems, and the midrange-performance ''Aridus'' systems using air cooling. During development, engineers so improved the air cooling system that Aquarius w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Q-Bus
The Q-bus, also known as the LSI-11 Bus, is one of several bus (computing), bus technologies used with Programmed Data Processor, PDP and VAX, MicroVAX computer systems previously manufactured by the Digital Equipment Corporation of Maynard, Massachusetts, Maynard, Massachusetts. The Q-bus is a less expensive version of Unibus using multiplexing so that address and data signals share the same wires. This allows both a physically smaller and less-expensive implementation of essentially the same functionality. Over time, the physical address range of the Q-bus was expanded from 16 to 18 and then 22 bits. Block transfer modes were also added to the Q-bus. Main features of the Q-bus The Q-bus is arranged as a series of Expansion card, modules installed in one or more Backplane, backplanes. Like the Unibus before it, the Q-bus uses: * ''Memory-mapped I/O'' * ''Byte addressing'' * A strict ''Master-slave (computers), master-slave'' relationship between devices on the bus * ''Asynchro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PDP-11
The PDP–11 is a series of 16-bit minicomputers originally sold by Digital Equipment Corporation (DEC) from 1970 into the late 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of all models were sold, making it one of DEC's most successful product lines. The PDP-11 is considered by some experts to be the most popular minicomputer. The PDP–11 included a number of innovative features in its instruction set and additional general-purpose registers that made it easier to program than earlier models in the PDP series. Further, the innovative Unibus system allowed external devices to be more easily interfaced to the system using direct memory access, opening the system to a wide variety of peripherals. The PDP–11 replaced the PDP–8 in many real-time computing applications, although both product lines lived in parallel for more than 10 years. The ease of programming of the PDP–11 made it popular for general-pur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Error-correcting Code
In computing, telecommunication, information theory, and coding theory, forward error correction (FEC) or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels. The central idea is that the sender encodes the message in a redundant way, most often by using an error correction code, or error correcting code (ECC). The redundancy allows the receiver not only to detect errors that may occur anywhere in the message, but often to correct a limited number of errors. Therefore a reverse channel to request re-transmission may not be needed. The cost is a fixed, higher forward channel bandwidth. The American mathematician Richard Hamming pioneered this field in the 1940s and invented the first error-correcting code in 1950: the Hamming (7,4) code. FEC can be applied in situations where re-transmissions are costly or impossible, such as one-way communication links or when transmitting to multiple receivers in m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zero Insertion Force
Zero insertion force (ZIF) is a type of IC socket or electrical connector that requires very little (but not literally zero) force for insertion. With a ZIF socket, before the IC is inserted, a lever or slider on the side of the socket is moved, pushing all the sprung contacts apart so that the IC can be inserted with very little force - generally the weight of the IC itself is sufficient and no external downward force is required. The lever is then moved back, allowing the contacts to close and grip the pins of the IC. ZIF sockets are much more expensive than standard IC sockets and also tend to take up a larger board area due to the space taken up by the lever mechanism. Typically, they are only used when there is a good reason to do so. Design A normal integrated circuit (IC) socket requires the IC to be pushed into sprung contacts which then grip by friction. For an IC with hundreds of pins, the total insertion force can be very large (hundreds of newtons), leading ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DECsystem
DECsystem was a line of server computers from Digital Equipment Corporation. They were based on MIPS architecture processors and ran DEC's version of the UNIX operating system, called ULTRIX. They ranged in size from workstation-style desktop enclosures to large pedestal cabinets. The DECSYSTEM name was used for later models of the PDP-10, namely the DECSYSTEM-10 and DECSYSTEM-20 series. Models DECsystem 3100 Identical to the DECstation 3100, but intended as a multiuser system. It was announced in early May 1989 at the UniForum exhibition in San Francisco. It was shipped in June 1989. Code name PMAX. DECsystem 5000 Series Rebranded Personal DECstation 5000 Series without graphics. Code name MAXINE. DECsystem 5000 Model 100 Series Rebranded DECstation 5000 Model 100 Series without graphics. Codename 3MIN. DECsystem 5000 Model 200 Series Rebranded DECstation 5000 Model 200 Series without graphics. Code name 3MAX. (5000/260 3MAX+). DECsystem 5100 A desktop unip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIPS Architecture
MIPS (Microprocessor without Interlocked Pipelined Stages) is a family of reduced instruction set computer (RISC) instruction set architectures (ISA)Price, Charles (September 1995). ''MIPS IV Instruction Set'' (Revision 3.2), MIPS Technologies, Inc. developed by MIPS Computer Systems, now MIPS Technologies, based in the United States. There are multiple versions of MIPS, including MIPS I, II, III, IV, and V, as well as five releases of MIPS32/64 (for 32- and 64-bit implementations, respectively). The early MIPS architectures were 32-bit; 64-bit versions were developed later. As of April 2017, the current version of MIPS is MIPS32/64 Release 6. MIPS32/64 primarily differs from MIPS I–V by defining the privileged kernel mode System Control Coprocessor in addition to the user mode architecture. The MIPS architecture has several optional extensions: MIPS-3D, a simple set of floating-point SIMD instructions dedicated to 3D computer graphics; MDMX (MaDMaX), a more extensive i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Standards
An open standard is a standard that is openly accessible and usable by anyone. It is also a common prerequisite that open standards use an open license that provides for extensibility. Typically, anybody can participate in their development due to their inherently open nature. There is no single definition, and interpretations vary with usage. Examples of open standards include the GSM, 4G, and 5G standards that allow most modern mobile phones to work world-wide. Definitions The terms ''open'' and ''standard'' have a wide range of meanings associated with their usage. There are a number of definitions of open standards which emphasize different aspects of openness, including the openness of the resulting specification, the openness of the drafting process, and the ownership of rights in the standard. The term "standard" is sometimes restricted to technologies approved by formalized committees that are open to participation by all interested parties and operate on a consensus bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backplane
A backplane or backplane system is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used to connect several printed circuit boards together to make up a complete computer system. Backplanes commonly use a printed circuit board, but wire-wrapped backplanes have also been used in minicomputers and high-reliability applications. A backplane is generally differentiated from a motherboard by the lack of on-board processing and storage elements. A backplane uses plug-in cards for storage and processing. Usage Early microcomputer systems like the Altair 8800 used a backplane for the processor and expansion cards. Backplanes are normally used in preference to cables because of their greater reliability. In a cabled system, the cables need to be flexed every time that a card is added or removed from the system; this flexing eventually cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 he was forced to resign in 1992, after the company had gone into precipitous decline. The company produced many different product lines over its history. It is best known for the work in the minicomputer market starting in the early 1960s. The company produced a series of machines known as the Programmed Data Processor, PDP line, with the PDP-8 and PDP-11 being among the most successful minis in history. Their success was only surpassed by another DEC product, the late-1970s VAX "supermini" systems that were designed to replace the PDP-11. Although a number of competitors had successfully competed with Digital through the 1970s, the VAX cemented the company's place as a leading vendor in the computer space. As microcomputers improved in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
