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PERQ Operating System
The PERQ, also referred to as the Three Rivers PERQ or ICL PERQ, was a pioneering workstation computer produced in the late 1970s through the early 1980s. In June 1979, the company took its very first order from the UK's Rutherford Appleton Laboratory and the computer was officially launched in August 1979 at SIGGRAPH in Chicago. It was the first commercially produced personal workstation with a Graphical User Interface. The design was heavily influenced by the original workstation computer, the Xerox Alto, which was never commercially produced. The origin of the name "PERQ" was chosen both as an acronym of "Pascal Engine that Runs Quicker," and to evoke the word ''perquisite'' commonly called ''perks'', that is employee additional benefits. The workstation was conceived by six former Carnegie Mellon University alumni and employees, Brian S. Rosen, James R. Teter, William H. Broadley, J. Stanley Kriz, Raj Reddy and Paul G. Newbury, who formed the startup Three Rivers Comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ICL PERQ 1 Workstation Edinburgh University
ICL may refer to: Companies and organizations * Idaho Conservation League * Imperial College London, a UK university * Indian Confederation of Labour * Indian Cricket League * Department_of_Chemistry,_University_of_Oxford, Inorganic Chemistry Laboratory of the University of Oxford * Israel Chemicals, an Israeli multi-national chemical company that produces and markets fertilizers, metals and other special-purpose chemical products * International Computers Limited, a UK company acquired by Fujitsu * International Confederation of Labor, a global anarcho-syndicalist union federation * International Consortium on Landslides, Kyoto, Japan Computing * Ice Lake (microprocessor), Ice Lake series Intel CPUs * ICO (file format)#Icon library, Icon library filename extension * Clean (programming language) source filename extension * Inter-Chassis Link, Brocade's name for an InterSwitch Trunk link Chemistry and biology * Idiopathic CD4+ lymphocytopenia, a medical condition * Implantable colla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollo Computer
Apollo Computer Inc., founded in 1980 in Chelmsford, Massachusetts, by William Poduska (a founder of Prime Computer) and others, developed and produced Apollo/Domain workstations in the 1980s. Along with Symbolics and Sun Microsystems, Apollo was one of the first vendors of graphical workstations in the 1980s. Like computer companies at the time and unlike manufacturers of IBM PC compatibles, Apollo produced much of its own hardware and software. Apollo was acquired by Hewlett-Packard in 1989 for US$476 million (equivalent to $ million in ), and gradually closed down over the period of 1990–1997. The brand (as "HP Apollo") was resurrected in 2014 as part of HP's high-performance computing portfolio. History Apollo was started in 1980, two years before Sun Microsystems. In addition to Poduska, the founders included Dave Nelson (Engineering), Mike Greata (Engineering), Charlie Spector (COO), Bob Antonuccio (Manufacturing), Gerry Stanley (Sales and Marketing), and Dave Lub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shugart Associates
Shugart Associates (later Shugart Corporation) was a computer peripheral manufacturer that dominated the floppy disk drive market in the late 1970s and is famous for introducing the -inch "Minifloppy" floppy disk drive. In 1979 it was one of the first companies to introduce a hard disk drive form factor compatible with a floppy disk drive, the SA1000 form factor compatible with the 8-inch floppy drive form factor. Founded in 1973, Shugart Associates was purchased in 1977 by Xerox, which then exited the business in 1985 and 1986, selling the brand name and the 8-inch floppy product line (in March 1986) to Narlinger Group, which ultimately ceased operations circa 1991. History Beginnings Alan Shugart, after a distinguished career at IBM and a few years at Memorex, decided to strike out on his own in 1973; after gathering venture capital, he started Shugart Associates. The original business plan was to build a small-business system (similar to the IBM 3740) dealing with the developm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random-access Memory
Random-access memory (RAM; ) is a form of computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A Random access, random-access memory device allows data items to be read (computer), read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks, CD-RWs, DVD-RWs and the older Magnetic tape data storage, magnetic tapes and drum memory), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement. RAM contains multiplexer, multiplexing and demultiplexing circuitry, to connect the data lines to the addressed storage for reading or writing the entry. Usually more than one bit of storage is accessed by the same address, and RAM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Word (data Type)
In computing, a word is the natural unit of data used by a particular processor design. A word is a fixed-sized datum handled as a unit by the instruction set or the hardware of the processor. The number of bits or digits in a word (the ''word size'', ''word width'', or ''word length'') is an important characteristic of any specific processor design or computer architecture. The size of a word is reflected in many aspects of a computer's structure and operation; the majority of the registers in a processor are usually word-sized and the largest datum that can be transferred to and from the working memory in a single operation is a word in many (not all) architectures. The largest possible address size, used to designate a location in memory, is typically a hardware word (here, "hardware word" means the full-sized natural word of the processor, as opposed to any other definition used). Documentation for older computers with fixed word size commonly states memory sizes in words ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Store
A 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). Implementation Early use 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. Modern VLSI processors instead use matrices of field-effect transistors to build the ROM and/or PLA structures used to control the processor as well as its internal sequencer in a microcoded implementation. IBM System/360 used a variety of techniques: CCROS (Card Capacitor Read-Only Storage) on the Model 30, TROS (Transformer Read-Only Storage) on the Model 40, and BCROS (Balanced Capacitor Read-Only Stora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AMD Am2900
Am2900 is a family of integrated circuits (ICs) created in 1975 by Advanced Micro Devices (AMD). They were constructed with bipolar devices, in a bit-slice topology, and were designed to be used as modular components each representing a different aspect of a computer control unit (CCU). By using the bit slicing technique, the Am2900 family was able to implement a CCU with data, addresses, and instructions to be any multiple of 4 bits by multiplying the number of ICs. One major problem with this modular technique was that it required a larger number of ICs to implement what could be done on a single CPU IC. The Am2901 chip was the arithmetic logic unit (ALU), and the "core" of the series. It could count using 4 bits and implement binary operations as well as various bit-shifting operations. The 2901 and some other chips in the family were second sourced by an unusually large number of other manufacturers, starting with Motorola and then Raytheon both in 1975 and also Cypr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arithmetic Logic Unit
In computing, an arithmetic logic unit (ALU) is a Combinational logic, combinational digital circuit that performs arithmetic and bitwise operations on integer binary numbers. This is in contrast to a floating-point unit (FPU), which operates on floating point numbers. It is a fundamental building block of many types of computing circuits, including the central processing unit (CPU) of computers, FPUs, and graphics processing units (GPUs). The inputs to an ALU are the data to be operated on, called operands, and a code indicating the operation to be performed; the ALU's output is the result of the performed operation. In many designs, the ALU also has status inputs or outputs, or both, which convey information about a previous operation or the current operation, respectively, between the ALU and external status registers. Signals An ALU has a variety of input and output net (electronics), nets, which are the electrical conductors used to convey Digital signal (electronics), digi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bit-slice
Bit 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. Recently it has been used in arithmetic logic units (ALUs) for quantum computers and as a software technique, e.g. for cryptography in x86 CPUs. Operational details Bit-slice processors (BSPs) usually include 1-, 2-, 4-, 8- or 16-bit arithmetic logic unit (ALU) and control lines (including carry or overflow signals that are internal to the processor in non-bitsliced CPU designs). For example, two 4-bit ALU chips could be arranged side by side, with control lines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
74S181
The 74181 is a 4-bit slice arithmetic logic unit (ALU), implemented as a 7400 series TTL integrated circuit. The first complete ALU on a single chip, it was used as the arithmetic/logic core in the CPUs of many historically significant minicomputers and other devices. The 74181 represents an evolutionary step between the CPUs of the 1960s, which were constructed using discrete logic gates, and today's single-chip microprocessor CPUs. Although no longer used in commercial products, the 74181 is still referenced in computer organization textbooks and technical papers. It is also sometimes used in "hands-on" college courses to train future computer architects. Specifications The 74181 is a 7400 series medium-scale integration (MSI) TTL integrated circuit, containing the equivalent of 75 logic gates and most commonly packaged as a 24-pin DIP. The 4-bit wide ALU can perform all the traditional add / subtract / decrement operations with or without carry, as well as AND / NAND, OR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circuitry required to perform the functions of a computer's central processing unit. The integrated circuit is capable of interpreting and executing program instructions and performing arithmetic operations. The microprocessor is a multipurpose, clock-driven, register-based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides results (also in binary form) as output. Microprocessors contain both combinational logic and sequential digital logic, and operate on numbers and symbols represented in the binary number system. The integration of a whole CPU onto a single or a few integrated circuits using Very-Large-Scale Integration (VLSI) greatly reduced the cost of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transistor–transistor Logic
Transistor–transistor logic (TTL) is a logic family built from bipolar junction transistors. Its name signifies that transistors perform both the logic function (the first "transistor") and the amplifying function (the second "transistor"), as opposed to earlier resistor–transistor logic (RTL) and diode–transistor logic (DTL). TTL integrated circuits (ICs) were widely used in applications such as computers, industrial controls, test equipment and instrumentation, consumer electronics, and synthesizers. After their introduction in integrated circuit form in 1963 by Sylvania Electric Products, TTL integrated circuits were manufactured by several semiconductor companies. The 7400 series by Texas Instruments became particularly popular. TTL manufacturers offered a wide range of logic gates, flip-flops, counters, and other circuits. Variations of the original TTL circuit design offered higher speed or lower power dissipation to allow design optimization. TTL devices were original ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
