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PDP-10
Digital Equipment Corporation (DEC)'s PDP-10, later marketed as the DECsystem-10, is a mainframe computer family manufactured beginning in 1966 and discontinued in 1983. 1970s models and beyond were marketed under the DECsystem-10 name, especially as the TOPS-10 operating system became widely used. The PDP-10's architecture is almost identical to that of DEC's earlier PDP-6, sharing the same 36-bit word length and slightly extending the instruction set (but with improved hardware implementation). Some aspects of the instruction set are unusual, most notably the ''byte'' instructions, which operate on bit fields of any size from 1 to 36 bits inclusive, according to the general definition of a byte as ''a contiguous sequence of a fixed number of bits''. The PDP-10 was found in many university computing facilities and research labs during the 1970s, the most notable being Harvard University's Aiken Computation Laboratory, MIT's AI Lab and Project MAC, Stanford's SAIL, Computer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TENEX (operating System)
TENEX is an operating system developed in 1969 by BBN for the PDP-10, which later formed the basis for Digital Equipment Corporation's TOPS-20 operating system. Background In the 1960s, BBN was involved in a number of LISP-based artificial intelligence projects for DARPA, many of which had very large (for the era) memory requirements. One solution to this problem was to add ''paging'' software to the LISP language, allowing it to write out unused portions of memory to disk for later recall if needed. One such system had been developed for the PDP-1 at MIT by Daniel Murphy before he joined BBN. Early DEC machines were based on an 18-bit word, allowing addresses to encode for a 256 kiloword memory. The machines were based on expensive core memory and included nowhere near the required amount. The pager used the most significant bits of the address to index a table of blocks on a magnetic drum that acted as the pager's ''backing store''. The software would fetch the pages if nee ... [...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 wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TOPS-10
TOPS-10 System (''Timesharing / Total Operating System-10'') is a discontinued operating system from Digital Equipment Corporation (DEC) for the PDP-10 (or DECsystem-10) mainframe computer family. Launched in 1967, TOPS-10 evolved from the earlier "Monitor" software for the PDP-6 and PDP-10 computers; this was renamed to TOPS-10 in 1970. Overview TOPS-10 supported shared memory and allowed the development of one of the first true multiplayer computer games. The game, called DECWAR, was a text-oriented ''Star Trek'' type game. Users at terminals typed in commands and fought each other in real time. TOPS-10 was also the home of the original Multi User Dungeon, MUD, the fore runner to today's MMORPGs. Another groundbreaking application was called ''FORUM''. This application was perhaps the first so-called ''CB Simulator'' that allowed users to converse with one another in what is now known as a chat room. This application showed the potential of multi-user communication and led ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incompatible Timesharing System
Incompatible Timesharing System (ITS) is a time-sharing operating system developed principally by the MIT Artificial Intelligence Laboratory, with help from Project MAC. The name is the jocular complement of the MIT Compatible Time-Sharing System (CTSS). ITS, and the software developed on it, were technically and culturally influential far beyond their core user community. Remote "guest" or "tourist" access was easily available via the early ARPAnet, allowing many interested parties to informally try out features of the operating system and application programs. The wide-open ITS philosophy and collaborative online community were a major influence on the hacker culture, as described in Steven Levy's book ''Hackers'', and were the direct forerunners of the free and open-source software, open-design, and Wiki movements. History ITS development was initiated in the late 1960s by those (the majority of the MIT AI Lab staff at that time) who disagreed with the direction taken by Proj ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PDP-6
The PDP-6, short for Programmed Data Processor model 6, is a computer developed by Digital Equipment Corporation (DEC) during 1963 and first delivered in the summer of 1964. It was an expansion of DEC's existing 18-bit systems to use a 36-bit data word, which was at that time a common word size for large machines like IBM mainframes. The system was constructed using the same germanium transistor-based System Module layout as DEC's earlier machines, like the PDP-1 and PDP-4. The system was designed with real-time computing use in mind, not just batch processing as was typical for most mainframes. This made it popular in university settings and its support for the Lisp language made it particularly useful in artificial intelligence labs like Project MAC at MIT. It was also complex, expensive, and unreliable as a result of its use of so many early-model transistors. Only 23 were sold, at prices ranging from $120,000 to $300,000. The lasting influence of the PDP-6 was its re-impl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DECSYSTEM-20
The DECSYSTEM-20 was a 36-bit Digital Equipment Corporation PDP-10 mainframe computer running the TOPS-20 operating system (products introduced in 1977). PDP-10 computers running the TOPS-10 operating system were labeled ''DECsystem-10'' as a way of differentiating them from the PDP-11. Later on, those systems running TOPS-20 (on the KL10 PDP-10 processors) were labeled ''DECSYSTEM-20'' (the block capitals being the result of a lawsuit brought against DEC by Singer, which once made a computer called " The System Ten"). The DECSYSTEM-20 was sometimes called PDP-20, although this designation was never used by DEC. Models The following models were produced: *DECSYSTEM-2020: KS10 bit-slice processor with up to 512 kilowords of solid state RAM (The ADP OnSite version of the DECSYSTEM-2020 supported 1 MW of RAM) *DECSYSTEM-2040: KL10 ECL processor with up to 1024 kilowords of magnetic core RAM *DECSYSTEM-2050: KL10 ECL processor with 2k words of cache and up to 1024 kilowords of R ... [...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 words ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CompuServe
CompuServe (CompuServe Information Service, also known by its initialism CIS) was an American online service provider, the first major commercial one in the world – described in 1994 as "the oldest of the Big Three information services (the others are Prodigy and America Online)." It dominated the field during the 1980s and remained a major influence through the mid-1990s. At its peak in the early 1990s, CIS was known for its online chat system, message forums covering a variety of topics, extensive software libraries for most computer platforms, and a series of popular online games, notably ''MegaWars III'' and ''Island of Kesmai''. It also was known for its introduction of the GIF format for pictures and as a GIF exchange mechanism. In 1997, 17 years after H&R Block had acquired CIS, the parent announced its desire to sell the company. A complex deal was worked out with WorldCom acting as a broker, resulting in CIS being sold to AOL. In 2015, Verizon acquired AOL, includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
36-bit
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 ea ... [...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, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WAITS
WAITS was a heavily modified variant of Digital Equipment Corporation's Monitor operating system (later renamed to, and better known as, "TOPS-10") for the PDP-6 and PDP-10 mainframe computers, used at the Stanford Artificial Intelligence Laboratory (SAIL) from the mid-1960s up until 1991; the mainframe computer it ran on also went by the name of "SAIL". Overview There was never an "official" expansion of WAITS, but a common variant was "West-coast Alternative to ITS"; another variant was "Worst Acronym Invented for a Timesharing System". The name was endorsed by the SAIL community in a public vote choosing among alternatives. Two of the other contenders were SAINTS ("Stanford AI New Timesharing System") and SINNERS ("Stanford Incompatible Non-New Extensively Rewritten System"), proposed by the systems programmers. Though WAITS was less visible than ITS, there was frequent exchange of people and ideas between the two communities, and innovations pioneered at WAITS exerted enormo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hacker Culture
The hacker culture is a subculture of individuals who enjoy—often in collective effort—the intellectual challenge of creatively overcoming the limitations of software systems or electronic hardware (mostly digital electronics), to achieve novel and clever outcomes. The act of engaging in activities (such as programming or other mediaThe Hacker Community and Ethics: An Interview with Richard M. Stallman, 2002 (gnu.org)) in a spirit of playfulness and exploration is termed ''hacking''. However, the defining characteristic of a is not the activities performed themselves (e.g. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
