The SDS 940 was Scientific Data Systems' (SDS) first machine designed to support time sharing directly, and was based on the SDS 930's 24-bit CPU built primarily of integrated circuits. Scientific Data Systems, or SDS, was an American Computer company founded in September 1961 by Max Palevsky, a veteran of Packard Bell Time-sharing refers to sharing a computing resource among many users by multitasking. The Scientific Data Systems SDS-930, was the first commercial Computer series to use Transistors ( PNP) The IBM System/360, announced in 1964, was an extremely popular computer system with 24-bit addressing and 32-bit general registers and arithmetic Microchipsjpg|right|thumb|200px|Microchips ( EPROM memory with a transparent window showing the integrated circuit inside It was announced in February 1966 and shipped in April, becoming a major part of Tymshare's expansion during the 1960s. Tymnet was an international data communications network headquartered in San Jose, California that utilized virtual call packet switched technology and used X The influential SRI "oN-Line System" (NLS) was based around SDS 940 hardware. SRI International, based in the United States is one of the world's largest contract Research institutes. NLS, or the "oN-Line System" was a revolutionary Computer collaboration system designed by Douglas Engelbart and the researchers
After SDS was acquired by Xerox in 1969 and became Xerox Data Systems, the SDS 940 was renamed as the XDS 940. Xerox Corporation ( (name ˈziːrɒks is a global document management company which manufactures and sells a range of color and black-and-white printers, multifunction
The design was originally created by the University of California, Berkeley, along with Tymshare, as part of their Project Genie that ran between 1964 and 1965. The University of California Berkeley (also referred to as Cal, Berkeley and UC Berkeley) is a major research university located in Berkeley Tymnet was an international data communications network headquartered in San Jose, California that utilized virtual call packet switched technology and used X Genie added memory and controller logic to an existing SDS 930 computer to give it paged virtual memory, which would be heavily copied by other designs. The Scientific Data Systems SDS-930, was the first commercial Computer series to use Transistors ( PNP) Virtual memory is a Computer system technique which gives an application program the impression that it has contiguous working memory while in fact it may be physically The 940 was simply a commercialized version of the Genie design, and remained backwardly compatible with their earlier models (with the exception of the 12-bit SDS 92).
Like most systems of the era, the machine was built with a bank of core memory as the primary storage, allowing between 16 and 64 kilowords. Magnetic core memory, or ferrite-core memory, is an early form of Random access Computer memory. This was backed up by a variety of secondary storage devices, including a 1376 kWord drum in Genie, or hard disks in the SDS models in the form of a drum-like 2097 kWord "fixed head" disk or a 16777 kWord traditional "floating head" model. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device The SDS machines also included a paper tape punch and reader, line printer, and a real-time clock. Punched tape or paper tape is a largely obsolete form of Data storage, consisting of a long strip of paper in which holes are punched to store data The line printer is a form of high speed impact printer in which one line of type is printed at a time They bootstrapped from paper tape. In Computing, booting ( booting up) is a bootstrapping process that starts Operating systems when the user turns on a Computer system
Software System
As of 1969, the XDS 940 Software System consisted of the following:
- Time-Sharing Monitor
- Time-Sharing Executive
- FORTRAN IV
- BASIC
The minimum configuration required to run the Software System included (partial list):
- Two 16K-word core memory modules (with multiple access)
- Two rapid-access disc (RAD) storage units and couplers (just under 4M character capacity each); optionally two more could be connected
- Disc file and coupler, with 67M characters of storage
- Magnetic tape control unit and two magnetic tape transports (controller supports up to 8)
- Asynchronous communication controller(s), supporting up to 64 teletypewriter lines each
Additional software was available from the XDS Users' Group Library, such as a string processing system, "SYSPOPs" (system programmed operators, which allow access to system services), CAL (Conversational Algebraic Language, a dialect of JOSS), QED (text editor) (a text editor), TAP (Time-sharing Assembly Program, an assembler), and DDT, a debugging tool. Fortran (previously FORTRAN) is a general-purpose, procedural, imperative Programming language that is especially suited to In Computer programming, BASIC (an Acronym for Beginner's All-purpose Symbolic Instruction Code) is a family of High-level programming languages Disk storage is a general category of a Computer storage mechanisms in which data is recorded on planar round and rotating surfaces ( disks, discs, or Magnetic tape is a medium for Magnetic recording generally consisting of a thin magnetizable coating on a long and narrow strip of Plastic. In Telecommunications, Asynchronous communication is transmission of data without the use of an external clock signal A teleprinter ( In Computer programming and some branches of Mathematics, a string is an ordered Sequence of Symbols. CAL (Conversational Algebraic Language was a Programming language and system designed and developed by Butler Lampson at Berkeley in 1967 This article is on the programming language See also Religion in China and Incense, Joss Stone for the British female soul singer or Joss Whedon QED is a line-oriented computer Text editor that was designed by Butler Lampson and L See the terminology section below for information regarding inconsistent use of the terms assembly and assembler For other expansions of "DDT" see DDT (disambiguation.
Notable Installations
A San Francisco counterculture community action group called Project One used a free surplus XDS 940 as described in Rolling Stone magazine in 1972.
References
- Xerox Data Systems, XDS 940 Computer (1969)
- Rolling Stone, Spacewar, 7 December 1972, loacated at http://www.wheels.org/spacewar/stone/rolling_stone.html
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic