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PDP-1
The PDP-1 (''Programmed Data Processor-1'') is the first computer in Digital Equipment Corporation's PDP series and was first produced in 1959. It is famous for being the computer most important in the creation of hacker culture at Massachusetts Institute of Technology, BBN and elsewhere. The PDP-1 is the original hardware for playing history's first game on a minicomputer, Steve Russell's ''Spacewar!'' Description The PDP-1 uses an 18-bit word size and has 4096 words as standard main memory (equivalent to 9,216 eight-bit bytes, though the system actually divides an 18-bit word into six-bit characters), upgradable to 65,536 words. The magnetic-core memory's cycle time is 5.35 microseconds (corresponding roughly to a clock speed of 187 kilohertz); consequently most arithmetic instructions take 10.7 microseconds (93,458 operations per second) because they use two memory cycles: the first to fetch the instruction, the second to fetch or store the data word. Signed numbers ar ... [...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 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 mid-1960s. The company produced a series of machines known as the 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 the late 1980s, especially w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmed Data Processor
Programmed Data Processor (PDP), referred to by some customers, media and authors as "Programmable Data Processor," is a term used by the Digital Equipment Corporation from 1957 to 1990 for several lines of minicomputers. The name 'PDP' intentionally avoids the use of the term 'computer'. At the time of the first PDPs, computers had a reputation of being large, complicated, and expensive machines. The venture capitalists behind Digital (especially Georges Doriot) would not support Digital's attempting to build a 'computer' and the term 'minicomputer' had not yet been coined. So instead, Digital used their existing line of logic modules to build a ''Programmed Data Processor'' and aimed it at a market that could not afford the larger computers. The various PDP machines can generally be grouped into families based on word length. Series Members of the PDP series include: ;PDP-1: The original PDP, an 18-bit 4-rack machine used in early time-sharing operating system work, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacewar!
''Spacewar!'' is a Space combat game, space combat video game developed in 1962 by Steve Russell (computer scientist), Steve Russell in collaboration with Martin Graetz, Wayne Wiitanen, Robert Alan Saunders, Bob Saunders, Steve Piner, and others. It was written for the newly installed Digital Equipment Corporation, DEC PDP-1 minicomputer at the Massachusetts Institute of Technology. After its initial creation, ''Spacewar!'' was expanded further by other students and employees of universities in the area, including Dan Edwards and Peter Samson. It was also spread to many of the few dozen installations of the PDP-1 computer, making ''Spacewar!'' the first known video game to be played at multiple computer installations. The game features two space vehicle, spaceships, "the needle" and "the wedge", engaged in a dogfight while maneuvering in the gravity well of a star. Both ships are controlled by human players. Each ship has limited weaponry and fuel for maneuvering, and the ships re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBN Time-Sharing System
The BBN Time-Sharing System was an early time-sharing system created at Bolt, Beranek and Newman (BBN) for the PDP-1 computer. It began operation in September 1962. History J. C. R. Licklider left MIT to become a vice president at Bolt Beranek and Newman in 1957. He learned about time-sharing from Christopher Strachey at a UNESCO-sponsored conference on Information Processing in Paris in June 1959. Digital Equipment Corporation's prototype PDP-1 was ready in November, 1959, and the machine was featured in the November/December issue of ''Datamation'' magazine. BBNer Ed Fredkin saw a prototype system at the Eastern Joint Computer Conference in Boston in December 1959, and was extremely interested. Given BBN's interest, DEC's founder and President Ken Olsen visited and explained that DEC had just completed construction of a prototype PDP-1, and that they needed a test site for a month. BBN agreed to be the test site, at its regular hourly rates, and then in early 1960 obtai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PDP-4
The PDP-4 was the successor to the Digital Equipment Corporation's PDP-1. History This 18-bit machine, first shipped in 1962, was a compromise: "with slower memory and different packaging" than the PDP-1, but priced at $65,000 - less than half the price of its predecessor. All later 18-bit PDP machines ( 7, 9 and 15) are based on a similar, but enlarged instruction set, more powerful than, but based on the same concepts as, the 12-bit PDP-5/PDP-8 series. Approximately 54 were sold. Hardware The system's memory cycle was 8 microseconds, compared to 5 microseconds for the PDP-1. The PDP-4 weighed about . Mass storage Both the PDP-1 and the PDP-4 were introduced as paper tape-based systems. The only use, if any, for IBM-compatible 200 BPI or 556 BPI magnetic tape was for data. The use of "mass storage" drums - not even a megabyte and non-removable - were an available option, but were not in the spirit of the “personal” or serially shared systems that DEC offered. It wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Word (computer Architecture)
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 word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steve Russell (computer Scientist)
Stephen Russell (born 1937), also nicknamed "Slug", is an American computer scientist most famous for creating ''Spacewar!'', well known for being the first widely distributed video game. Biography Born in Hartford, Connecticut, Russell attended Dartmouth College in Hanover, New Hampshire, from 1954 to 1958. Russell wrote the first two implementations of the programming language Lisp for the IBM 704 mainframe computer. It was Russell who realized that the concept of universal functions could be applied to the language. By implementing the Lisp universal evaluator in a lower-level language, it became possible to create the Lisp interpreter; prior development work on the language had focused on compiling the language. He invented the continuation to solve a double recursion problem for one of the users of his Lisp implementation. In 1962, Russell created and designed ''Spacewar!'', with the fellow members of the Tech Model Railroad Club at the Massachusetts Institute of Tech ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolt, Beranek And Newman
Raytheon BBN (originally Bolt Beranek and Newman Inc.) is an American research and development company, based next to Fresh Pond in Cambridge, Massachusetts, United States. In 1966, the Franklin Institute awarded the firm the Frank P. Brown Medal, in 1999 BBN received the IEEE Corporate Innovation Recognition, and on 1 February 2013, BBN was awarded the National Medal of Technology and Innovation, the highest honors that the U.S. government bestows upon scientists, engineers and inventors, by President Barack Obama. It became a wholly owned subsidiary of Raytheon in 2009. History BBN has its roots in an initial partnership formed on 15 October 1948 between Leo Beranek and Richard Bolt, professors at the Massachusetts Institute of Technology. Bolt had won a commission to be an acoustic consultant for the new United Nations permanent headquarters to be built in New York City. Realizing the magnitude of the project at hand, Bolt had pulled in his MIT colleague Beranek for he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures. To disambiguate arbitrarily sized bytes from the common 8-bit definition, network protocol documents such as The Internet Protocol () refer to an 8-bit byte as an octet. Those bits in an octet are usually counted with numbering from 0 to 7 or 7 to 0 depending on the bit endianness. The first bit is number 0, making the eighth bit number 7. The size of the byte has historically been hardware-dependent and no definitive standards existed that mandated the size. Sizes from 1 to 48 bits have been used. The six-bit character code was an often-used implementation in early encoding systems, and computers using six-bit and nine-bit bytes were common in the 1960s. These systems often had memory wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 society. History The museum's origins date to 1968 when Gordon Bell began a quest for a historical collection and, at that same time, others were looking to preserve the Whirlwind computer. The resulting ''Museum Project'' had its first exhibit in 1975, located in a converted coat closet in a DEC lobby. In 1978, the museum, now ''The Digital Computer Museum'' (TDCM), moved to a larger DEC lobby in Marlborough, Massachusetts. Maurice Wilkes presented the first lecture at TDCM in 1979 – the presentation of such lectures has continued to the present time. TDCM incorporated as '' The Computer Museum'' (TCM) in 1982. In 1984, TCM moved to Boston, locating on Museum Wharf. In 1996/1997, the TCM History Center (TCMHC) was established; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic-core Memory
Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, core. Core memory uses toroids (rings) of a hard magnetic material (usually a semi-hard ferrite) as transformer cores, where each wire threaded through the core serves as a transformer winding. Two or more wires pass through each core. Magnetic hysteresis allows each of the cores to "remember", or store a state. Each core stores one bit of information. A core can be magnetized in either the clockwise or counter-clockwise direction. The value of the bit stored in a core is zero or one according to the direction of that core's magnetization. Electric current pulses in some of the wires through a core allow the direction of the magnetization in that core to be set in either direction, thus storing a one or a zero. Another wire through each core, the sense wire, is used to detect whether the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
18-bit
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] |
