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FLEX (operating System)
FLEX is a discontinued single-tasking operating system developed by Technical Systems Consultants (TSC) of West Lafayette, Indiana, for the Motorola 6800 in 1976. Overview The original version was distributed on 8" floppy disks; the (smaller) version for 5.25" floppies is called mini-Flex. It was also later ported to the Motorola 6809; that version is called Flex09. All versions are text-based and intended for use on display devices ranging from printing terminals like the Teletype Model 33 ASR to smart terminals. While no graphic displays are supported by TSC software, some hardware supports elementary graphics and pointing devices. FLEX is a disk-based operating system, using 256-byte sectors on soft-sectored floppies; the disk structure uses linkage bytes in each sector to indicate the next sector in a file or free list. The directory structure is simplified as a result. TSC (and others) provide several programming languages including BASIC in two flavors (standard and ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical Systems Consultants
Technical Systems Consultants (TSC) was a United States software company. Headquartered first in West Lafayette, Indiana (it was started by Don Kinzer and Dave Shirk, EE graduate students at Purdue University) and later (1980) moved to Chapel Hill, North Carolina, it was the foremost supplier of software for SWTPC compatible hardware, as well as many other early makes of personal computers. Their software included operating systems (FLEX (operating system), Flex, mini-FLEX, FLEX09, and UniFlex) and various languages (several BASIC variants, FORTRAN, Pascal (programming language), Pascal, C (programming language), C and assemblers). References Software companies based in North Carolina Defunct companies based in North Carolina Defunct software companies of the United States {{US-software-company-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smoke Signal Broadcasting
Smoke is a suspension of airborne particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires (including stoves, candles, internal combustion engines, oil lamps, and fireplaces), but may also be used for pest control (fumigation), communication (smoke signals), defensive and offensive capabilities in the military (smoke screen), cooking, or smoking (tobacco, cannabis, etc.). It is used in rituals where incense, sage, or resin is burned to produce a smell for spiritual or magical purposes. It can also be a flavoring agent and preservative. Smoke inhalation is the primary cause of death in victims of indoor fires. The smoke kills by a combination of thermal damage, poisoning and pulmonary irritation caused by carbon monoxide, hydrogen cyanide and other combustion products. Smoke is an aerosol (or mist) of solid particl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echo (command)
In computing, echo is a command that outputs the strings that are passed to it as arguments. It is a command available in various operating system shells and typically used in shell scripts and batch files to output status text to the screen or a computer file, or as a source part of a pipeline. Implementations The command is available in the following operating systems: * Multics * TSC FLEX * MetaComCo TRIPOS * Zilog Z80-RIO * Microware OS-9 * DOS * Acorn Computers Panos * Digital Research FlexOS * IBM OS/2 * Microsoft Windows * ReactOS * HP MPE/iX * KolibriOS * SymbOS * Unix and Unix-like operating systems Many shells, including all Bourne-like (such as Bash or zsh) and Csh-like shells as well as COMMAND.COM and cmd.exe implement echo as a builtin command. The command is also available in the EFI shell. History echo began within Multics. After it was programmed in C by Doug McIlroy as a "finger exercise" and proved to be useful, it became part of Version 2 Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Date (command)
In computer science and computer programming, system time represents a computer system's notion of the passage of time. In this sense, ''time'' also includes the passing of days on the calendar. System time is measured by a ''system clock'', which is typically implemented as a simple count of the number of ''ticks'' that have transpired since some arbitrary starting date, called the ''epoch''. For example, Unix and POSIX-compliant systems encode system time ("Unix time") as the number of seconds elapsed since the start of the Unix epoch at 1 January 1970 00:00:00 UT, with exceptions for leap seconds. Systems that implement the 32-bit and 64-bit versions of the Windows API, such as Windows 9x and Windows NT, provide the system time as both , represented as a year/month/day/hour/minute/second/milliseconds value, and , represented as a count of the number of 100-nanosecond ticks since 1 January 1601 00:00:00 UT as reckoned in the proleptic Gregorian calendar. System time can be c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copy (command)
Copy may refer to: *Copying or the product of copying (including the plural "copies"); the duplication of information or an artifact **Cut, copy and paste, a method of reproducing text or other data in computing **File copying **Photocopying, a process which makes paper copies of documents and other visual images **Fax, a telecommunications technology used to transfer facsimile copies of documents, especially over the telephone network **Facsimile, a copy or reproduction that is as true to the original source as possible **Replica, a copy closely resembling the original concerning its shape and appearance **Term of art in U.S. copyright law meaning a material object in which a work of authorship has been embodied, such as a book * Copy (command), a shell command on DOS and Windows systems *Copy (publishing), written content in publications, in contrast to photographs or other elements of layout. **The output of journalists and authors, ready for copy editing and typesetting **T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backup
In information technology, a backup, or data backup is a copy of computer data taken and stored elsewhere so that it may be used to restore the original after a data loss event. The verb form, referring to the process of doing so, is "back up", whereas the noun and adjective form is "backup". Backups can be used to recover data after its loss from data deletion or corruption, or to recover data from an earlier time. Backups provide a simple form of disaster recovery; however not all backup systems are able to reconstitute a computer system or other complex configuration such as a computer cluster, active directory server, or database server. A backup system contains at least one copy of all data considered worth saving. The data storage requirements can be large. An information repository model may be used to provide structure to this storage. There are different types of data storage devices used for copying backups of data that is already in secondary storage onto archive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command (computing)
In computing, a command is a directive to a computer program to perform a specific task. It may be issued via a command-line interface, such as a shell, or as input to a network service as part of a network protocol, or as an event in a graphical user interface triggered by the user selecting an option in a menu. Specifically, the term ''command'' is used in imperative computer languages. The name arises because statements in these languages are usually written in a manner similar to the imperative mood used in many natural languages. If one views a statement in an imperative language as being like a sentence in a natural language, then a command is generally like a verb in such a language. Many programs allow specially formatted arguments, known as flags or options, which modify the default behaviour of the program, while further arguments may provide objects, such as files, to act on. As an analogy to a natural language, the flags are adverbs, while the other arguments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dragon 32/64
The Dragon 32 and Dragon 64 are home computers that were built in the 1980s. The Dragons are very similar to the TRS-80 Color Computer, and were produced for the European market by Dragon Data, Ltd., initially in Swansea, Wales before moving to Port Talbot, Wales (until 1984) and by Eurohard S.A. in Casar de Cáceres, Spain (from 1984 to 1987), and for the US market by Tano of New Orleans, Louisiana. The model numbers reflect the primary difference between the two machines, which have 32 and 64 kilobytes of RAM, respectively. Product history Dragon Data entered the market in August 1982 with the Dragon 32. The Dragon 64 followed a year later. The computers sold well initially and attracted the interest of independent software developers including Microdeal. A companion magazine, '' Dragon User'', began publication shortly after the microcomputer's launch. Despite this initial success, there were two technical impediments to the Dragon's acceptance. The graphics capabili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Memory Access
Direct memory access (DMA) is a feature of computer systems and allows certain hardware subsystems to access main system memory independently of the central processing unit (CPU). Without DMA, when the CPU is using programmed input/output, it is typically fully occupied for the entire duration of the read or write operation, and is thus unavailable to perform other work. With DMA, the CPU first initiates the transfer, then it does other operations while the transfer is in progress, and it finally receives an interrupt from the DMA controller (DMAC) when the operation is done. This feature is useful at any time that the CPU cannot keep up with the rate of data transfer, or when the CPU needs to perform work while waiting for a relatively slow I/O data transfer. Many hardware systems use DMA, including disk drive controllers, graphics cards, network cards and sound cards. DMA is also used for intra-chip data transfer in multi-core processors. Computers that have DMA channels can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
