In a computer's central processing unit (CPU), the accumulator is a register in which intermediate arithmetic logic unit results are stored.
In computer science, an integer is a datum of integral data type, a data type that represents some range of mathematical integers. Integral data types may be of different sizes and may or may not be allowed to contain negative values. Integers are commonly represented in a computer as a group of binary digits (bits). The size of the grouping varies so the set of integer sizes available varies between different types of computers. Computer hardware nearly always provides a way to represent a processor register or memory address as an integer.
The IBM 1620 was announced by IBM on October 21, 1959, and marketed as an inexpensive scientific computer. After a total production of about two thousand machines, it was withdrawn on November 19, 1970. Modified versions of the 1620 were used as the CPU of the IBM 1710 and IBM 1720 Industrial Process Control Systems.
The IBM 650 Magnetic Drum Data-Processing Machine is an early digital computer produced by IBM in the mid-1950s. It was the first mass produced computer in the world. Almost 2,000 systems were produced, the last in 1962, and it was the first computer to make a meaningful profit. The first one was installed in late 1954 and it was the most-popular computer of the 1950s.
A one-instruction set computer (OISC), sometimes called an ultimate reduced instruction set computer (URISC), is an abstract machine that uses only one instruction – obviating the need for a machine language opcode. With a judicious choice for the single instruction and given infinite resources, an OISC is capable of being a universal computer in the same manner as traditional computers that have multiple instructions. OISCs have been recommended as aids in teaching computer architecture and have been used as computational models in structural computing research. The first carbon nanotube computer is a 1-bit one-instruction set computer.
MIX is a hypothetical computer used in Donald Knuth's monograph, The Art of Computer Programming (TAOCP). MIX's model number is 1009, which was derived by combining the model numbers and names of several contemporaneous, commercial machines deemed significant by the author. Also, "MIX" read as a Roman numeral is 1009.
The HP-35 was Hewlett-Packard's first pocket calculator and the world's first scientific pocket calculator: a calculator with trigonometric and exponential functions. It was introduced in 1972.
In computing, a memory address is a reference to a specific memory location used at various levels by software and hardware. Memory addresses are fixed-length sequences of digits conventionally displayed and manipulated as unsigned integers. Such numerical semantic bases itself upon features of CPU, as well upon use of the memory like an array endorsed by various programming languages.
The Burroughs B2500 through Burroughs B4900 was a series of mainframe computers developed and manufactured by Burroughs Corporation in Pasadena, California, United States, from 1966 to 1991. They were aimed at the business world with an instruction set optimized for the COBOL programming language. They were also known as Burroughs Medium Systems, by contrast with the Burroughs Large Systems and Burroughs Small Systems.
The UNIVAC III, designed as an improved transistorized replacement for the vacuum tube UNIVAC I and UNIVAC II computers, was introduced in June 1962, with Westinghouse agreeing to furnish system programing and marketing on June 1, 1962. It was designed to be compatible for all data formats. However the word size and instruction set were completely different; this presented significant difficulty as all programs had to be rewritten, so many customers switched to different vendors instead of upgrading existing UNIVACs.
The Western Design Center (WDC) 65C02 microprocessor is an enhanced CMOS version of the popular nMOS-based 8-bit MOS Technology 6502. The 65C02 fixed several problems in the original 6502 and added some new instructions, but its main feature was greatly lowered power usage, on the order of 10 to 20 times less than the original 6502 running at the same speed. The reduced power consumption made the 65C02 useful in portable computer roles and microcontroller systems in industrial settings. It has been used in some home computers, as well as in embedded applications, including medical-grade implanted devices.
An instruction set simulator (ISS) is a simulation model, usually coded in a high-level programming language, which mimics the behavior of a mainframe or microprocessor by "reading" instructions and maintaining internal variables which represent the processor's registers.
NAR 1 or just NAR was a theoretical model of a computer created by Faculty of Mathematics of University of Belgrade professor Nedeljko Parezanović. It was used for Assembly language and Computer architecture courses.
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 structure using magnetic-core memory. The instructions can use a memory slab as either two 6-bit alphanumeric characters or as three 4-bit BCD digits. Basic memory is 5000 "slabs" of handmade core memory, which is expandable to a maximum of 40,000 slabs in four refrigerator-size cabinets. The main processor includes three cabinets and a console section that houses the power supply, keyboard, output writer, and a panel with lights that indicate the current status of the program counter, registers, arithmetic accumulator, and system errors. Input/Output is by direct parallel connections to each type of peripheral through a two-cable bundle with 1-inch-thick cables. Some devices like magnetic tape and the CRAM are daisy-chained to allow multiple drives to be connected.
The Little Man Computer (LMC) is an instructional model of a computer, created by Dr. Stuart Madnick in 1965. The LMC is generally used to teach students, because it models a simple von Neumann architecture computer—which has all of the basic features of a modern computer. It can be programmed in machine code or assembly code.
The Olivetti Programma 101, also known as Perottina or P101, is one of the first "all in one" commercial desktop programmable calculators, although not the first. Produced by Italian manufacturer Olivetti, based in Ivrea, Piedmont, and invented by the Italian engineer Pier Giorgio Perotto, the P101 used many features of large computers of that period. It was launched at the 1964 New York World's Fair; volume production started in 1965. A futuristic design for its time, the Programma 101 was priced at $3,200 (equivalent to $27,500 in 2021). About 44,000 units were sold, primarily in the US.
Ferranti's Sirius was a small computer released in 1961. Designed to be used in smaller offices without a dedicated programming staff, the Sirius used decimal arithmetic instead of binary, supported Autocode to ease programming, was designed to fit behind a standard office desk, and ran on UK standard mains electricity with no need for cooling. It was also fairly slow, with instruction speeds around 4,000 operations per second, and had limited main memory based on delay lines, but as Ferranti pointed out, its price/performance ratio was difficult to beat.
CPU Sim is a software development environment for the simulation of simple computers. It was developed by Dale Skrien to help students understand computer architectures. With this application the user is able to simulate new or existing simple CPUs. Users can create new virtual CPUs with custom machine language instructions, which are implemented by a sequence of micro instructions. CPU Sim allows the user to edit and run assembly language programs for the CPU being simulated.
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.
The City & Guilds Mnemonic Code and its associated City & Guilds Computer was a specification for an assembler language and a virtual computer system that ran it. It was introduced in 1964 by the City and Guilds of London Institute and used as the basis for a number of computer programming and administration courses. The computer model was deliberately very simple, and operational systems were implemented as interpreters on a number of mainframe computers like the ICL 1900 series and Elliot 900 family. An updated version was released in 1968.
