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Comparison Of Instruction Set Architectures
An instruction set architecture (ISA) is an abstract model of a computer, also referred to as computer architecture. A realization of an ISA is called an ''implementation''. An ISA permits multiple implementations that may vary in performance, physical size, and monetary cost (among other things); because the ISA serves as the interface between software and hardware. Software that has been written for an ISA can run on different implementations of the same ISA. This has enabled binary compatibility between different generations of computers to be easily achieved, and the development of computer families. Both of these developments have helped to lower the cost of computers and to increase their applicability. For these reasons, the ISA is one of the most important abstractions in computing today. An ISA defines everything a machine language programmer needs to know in order to program a computer. What an ISA defines differs between ISAs; in general, ISAs define the supported data ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Set Architecture
In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ''implementation''. In general, an ISA defines the supported instructions, data types, registers, the hardware support for managing main memory, fundamental features (such as the memory consistency, addressing modes, virtual memory), and the input/output model of a family of implementations of the ISA. An ISA specifies the behavior of machine code running on implementations of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as performance, physical size, and monetary cost (among other things), but that are capable of running the same machine code, so that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Number
A binary number is a number expressed in the base-2 numeral system or binary numeral system, a method of mathematical expression which uses only two symbols: typically "0" (zero) and "1" ( one). The base-2 numeral system is a positional notation with a radix of 2. Each digit is referred to as a bit, or binary digit. Because of its straightforward implementation in digital electronic circuitry using logic gates, the binary system is used by almost all modern computers and computer-based devices, as a preferred system of use, over various other human techniques of communication, because of the simplicity of the language and the noise immunity in physical implementation. History The modern binary number system was studied in Europe in the 16th and 17th centuries by Thomas Harriot, Juan Caramuel y Lobkowitz, and Gottfried Leibniz. However, systems related to binary numbers have appeared earlier in multiple cultures including ancient Egypt, China, and India. Leibniz was specifica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MC68000
The Motorola 68000 (sometimes shortened to Motorola 68k or m68k and usually pronounced "sixty-eight-thousand") is a 16/32-bit complex instruction set computer (CISC) microprocessor, introduced in 1979 by Motorola Semiconductor Products Sector. The design implements a 32-bit instruction set, with 32-bit registers and a 16-bit internal data bus. The address bus is 24 bits and does not use memory segmentation, which made it easier to program for. Internally, it uses a 16-bit data arithmetic logic unit (ALU) and two more 16-bit ALUs used mostly for addresses, and has a 16-bit external data bus. For this reason, Motorola termed it a 16/32-bit processor. As one of the first widely available processors with a 32-bit instruction set, and running at relatively high speeds for the era, the 68k was a popular design through the 1980s. It was widely used in a new generation of personal computers with graphical user interfaces, including the Macintosh 128K, Amiga, Atari ST, and X68000. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
8080
The Intel 8080 (''"eighty-eighty"'') is the second 8-bit microprocessor designed and manufactured by Intel. It first appeared in April 1974 and is an extended and enhanced variant of the earlier 8008 design, although without binary compatibility.'' Electronic News'' was a weekly trade newspaper. The same advertisement appeared in the May 2, 1974 issue of ''Electronics'' magazine. The initial specified clock rate or frequency limit was 2 MHz, with common instructions using 4, 5, 7, 10, or 11 cycles. As a result, the processor is able to execute several hundred thousand instructions per second. Two faster variants, the 8080A-1 (sometimes referred to as the 8080B) and 8080A-2, became available later with clock frequency limits of 3.125 MHz and 2.63 MHz respectively. The 8080 needs two support chips to function in most applications: the i8224 clock generator/driver and the i8228 bus controller. It is implemented in N-type metal-oxide-semiconductor logic (NMOS) using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Set
In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ''implementation''. In general, an ISA defines the supported instructions, data types, registers, the hardware support for managing main memory, fundamental features (such as the memory consistency, addressing modes, virtual memory), and the input/output model of a family of implementations of the ISA. An ISA specifies the behavior of machine code running on implementations of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as performance, physical size, and monetary cost (among other things), but that are capable of running the same machine code, so that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
60-bit Computing
A 60-bit word is typically used for high-precision floating-point calculations; it can also store 10 6-bit characters. Examples The only widely-used computers with 60-bit words were produced by Control Data Corporation (CDC), including the CDC 6000 series, the CDC 7600, and the CDC Cyber 70 and 170 series. Though the addressable unit was the 60-bit word, instructions were either 15 or 30 bits. Early design documents for the IBM 7030 Stretch tentatively specified its word length as 60 bits; the final design used 64.Werner Buchholz, "Memory Word Length"STRETCH Memo no. 40 July 31, 1956, archived at the Computer History Museum The Computer History Museum (CHM) is a museum of computer history, located in Mountain View, California. The museum presents stories and artifacts of Silicon Valley and the information age, and explores the computing revolution and its impact on ... Emulator Museum examples of 60-bit CDC machines exist. There also exists an emulator for the series whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
48-bit Computing
In computer architecture, 48-bit integers can represent 281,474,976,710,656 (248 or 2.814749767×1014) discrete values. This allows an unsigned binary integer range of 0 through 281,474,976,710,655 (248 − 1) or a signed two's complement range of -140,737,488,355,328 (-247) through 140,737,488,355,327 (247 − 1). A 48-bit memory address can directly address every byte of 256 terabytes of storage. 48-bit can refer to any other data unit that consumes 48 bits (6 octets) in width. Examples include 48-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size. Word size Computers with 48-bit words include the AN/FSQ-32, CDC 1604/ upper-3000 series, BESM-6, Ferranti Atlas, Philco TRANSAC S-2000 and Burroughs large systems. The Honeywell DATAmatic 1000, the MANIAC II, the MANIAC III, the Brookhaven National Laboratory Merlin, the Philco CXPQ, the Ferranti Orion, the Telefunken Rechner TR 440, the ICT 1301, and many other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliott 803
The Elliott 803 is a small, medium-speed transistor digital computer which was manufactured by the British company Elliott Brothers in the 1960s. About 211 were built. History The 800 series began with the 801, a one-off test machine built in 1957. The 802 was a production model but only seven were sold between 1958 and 1961. The short-lived 803A was built in 1959 and first delivered in 1960; the 803B was built in 1960 and first delivered in 1961. Over 200 Elliott 803 computers were delivered to customers, at a unit price of about £29,000 in 1960 (roughly ). Most sales were of the 803B version with more parallel paths internally, larger memory and hardware floating-point operations. The Elliott 803 was the computer used in the ISI-609, the world's first process or industrial control system, wherein the 803 was a data logger. It was used for this purpose at the US's first dual-purpose nuclear reactor, the N-Reactor. A significant number of British universities had an Ellio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
36-bit Computing
36-bit computers were popular in the early mainframe computer era from the 1950s through the early 1970s. Starting in the 1960s, but especially the 1970s, the introduction of 7-bit ASCII and 8-bit EBCDIC led to the move to machines using 8-bit bytes, with word sizes that were multiples of 8, notably the 32-bit IBM System/360 mainframe and Digital Equipment VAX and Data General MV series superminicomputers. By the mid-1970s the conversion was largely complete, and microprocessors quickly moved from 8-bit to 16-bit to 32-bit over a period of a decade. The number of 36-bit machines rapidly fell during this period, offered largely for backward compatibility purposes running legacy programs. History Prior to the introduction of computers, the state of the art in precision scientific and engineering calculation was the ten-digit, electrically powered, mechanical calculator, such as those manufactured by Friden, Marchant and Monroe. These calculators had a column of keys for eac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
24-bit Computing
Notable 24-bit machines include the CDC 924 – a 24-bit version of the CDC 1604, CDC lower 3000 series, SDS 930 and SDS 940, the ICT 1900 series, the Elliott 4100 series, and the Datacraft minicomputers/Harris H series. The term SWORD is sometimes used to describe a 24-bit data type with the S prefix referring to sesqui. The range of unsigned integers that can be represented in 24 bits is 0 to 16,777,215 ( in hexadecimal). The range of signed integers that can be represented in 24 bits is −8,388,608 to 8,388,607. Usage The IBM System/360, announced in 1964, was a popular computer system with 24-bit addressing and 32-bit general registers and arithmetic. The early 1980s saw the first popular personal computers, including the IBM PC/AT with an Intel 80286 processor using 24-bit addressing and 16-bit general registers and arithmetic, and the Apple Macintosh 128K with a Motorola 68000 processor featuring 24-bit addressing and 32-bit registers. The eZ80 is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
18-bit Computing
18 binary digits have (1000000 octal, 40000 hexadecimal) distinct combinations. 18 bits was a common word size for smaller computers in the 1960s, when large computers often used 36 bit words and 6-bit character sets, sometimes implemented as extensions of BCD, were the norm. There were also 18-bit teletypes experimented with in the 1940s. Example computer architectures Possibly the most well-known 18-bit computer architectures are the PDP-1, PDP-4, PDP-7, PDP-9 and PDP-15 minicomputers produced by Digital Equipment Corporation from 1960 to 1975. Digital's PDP-10 used 36-bit words but had 18-bit addresses. The UNIVAC produced several 18-bit computers, including the UNIVAC 418 and several military systems. The IBM 7700 Data Acquisition System was announced by IBM on December 2, 1963. The BCL Molecular 18 was a group of systems designed and manufactured in the UK in the 1970s and 1980s. The NASA Standard Spacecraft Computer NSSC-1 was developed as a standard component f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
12-bit Computing
Possibly the best-known 12-bit CPU is the PDP-8 and its relatives, such as the Intersil 6100 microprocessor produced in various forms from August 1963 to mid-1990. Many Analog-to-digital converter, 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 Word (computer architecture), 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 systems * Digital Equipment Corporation ** Programmed Data Processor, PDP-5 ** PDP-8 *** DECmate, a personal computer based o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
