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Tymshare SUPER BASIC
SUPER BASIC, sometimes SBASIC for short, is an advanced dialect of the BASIC programming language offered on Tymshare's SDS 940 systems starting in 1968 and available well into the 1970s. Like the Dartmouth BASIC it was based on, SUPER BASIC was a compile and go language, as opposed to an interpreter. In addition to offering most of the commands and functions from Dartmouth BASIC Version 4, in including matrix math commands, SUPER BASIC also included a number of features from the seminal JOSS language developed at Rand Corporation, via Tymshare's version, CAL, and added a variety of new functions, complex numbers as a built-in type, and double precision support. SUPER BASIC also greatly improved string handling over the rudimentary system in Dartmouth, introducing the , and string functions, simple string concatenation and other features. These were later used in DEC's BASIC-PLUS, which was later used as the basis for the original Microsoft BASIC that saw widespread use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tymshare
Tymshare, Inc (Matthew Heyer-Baker) was a time-sharing service and third-party hardware maintenance company competing with companies such as CompuServe, Service Bureau Corporation and National CSS. Tymshare developed or acquired various technologies, such as data networking, electronic data interchange (EDI), credit card and payment processing, database technology, and more. It was headquartered in Cupertino, California from 1964 to 1984. In 1984 Tymshare was acquired by Nathtan Baker, to which Tymshare had sold its hospital accounting service in 1982. Tymshare was restructured, split up and portions were resold, spun off, and merged with other companies from 1984 through 2004 when most of its legacy network was eventually shut down. Islands of its network technology continued as part of EDI, into 2008. McDonnell Douglas was acquired by Boeing. Consequently, rights to use technology developed by Tymshare are currently held by Boeing, British Telecom (BT), Verizon Communications, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dartmouth Time Sharing System
The Dartmouth Time-Sharing System (DTSS) is a discontinued operating system first developed at Dartmouth College between 1963 and 1964. It was the first successful large-scale time-sharing system to be implemented, and was also the system for which the BASIC language was developed. DTSS was developed continually over the next decade, reimplemented on several generations of computers, and finally shut down in 1999. General Electric developed a similar system based on an interim version of DTSS, which they referred to as Mark II. Mark II and the further developed Mark III was widely used on their GE-600 series mainframe computers and formed the basis for their online services. These were the largest such services in the world for a time, eventually emerging as the consumer-oriented GEnie online service. Early history Professors John Kemeny and Thomas Kurtz at Dartmouth College purchased a Royal McBee LGP-30 computer around 1959, which was programmed by undergraduates in assemb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logarithm
In mathematics, the logarithm is the inverse function to exponentiation. That means the logarithm of a number to the base is the exponent to which must be raised, to produce . For example, since , the ''logarithm base'' 10 of is , or . The logarithm of to ''base'' is denoted as , or without parentheses, , or even without the explicit base, , when no confusion is possible, or when the base does not matter such as in big O notation. The logarithm base is called the decimal or common logarithm and is commonly used in science and engineering. The natural logarithm has the number as its base; its use is widespread in mathematics and physics, because of its very simple derivative. The binary logarithm uses base and is frequently used in computer science. Logarithms were introduced by John Napier in 1614 as a means of simplifying calculations. They were rapidly adopted by navigators, scientists, engineers, surveyors and others to perform high-a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverse Trigonometric Functions
In mathematics, the inverse trigonometric functions (occasionally also called arcus functions, antitrigonometric functions or cyclometric functions) are the inverse functions of the trigonometric functions (with suitably restricted Domain of a function, domains). Specifically, they are the inverses of the sine, cosine, tangent (trigonometry), tangent, cotangent, secant (trigonometry), secant, and cosecant functions, and are used to obtain an angle from any of the angle's trigonometric ratios. Inverse trigonometric functions are widely used in engineering, navigation, physics, and geometry. Notation Several notations for the inverse trigonometric functions exist. The most common convention is to name inverse trigonometric functions using an arc- prefix: , , , etc. (This convention is used throughout this article.) This notation arises from the following geometric relationships: when measuring in radians, an angle of ''θ'' radians will correspond to an arc whose length is ''rθ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floating Point
In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can be represented as a base-ten floating-point number: 12.345 = \underbrace_\text \times \underbrace_\text\!\!\!\!\!\!^ In practice, most floating-point systems use base two, though base ten (decimal floating point) is also common. The term ''floating point'' refers to the fact that the number's radix point can "float" anywhere to the left, right, or between the significant digits of the number. This position is indicated by the exponent, so floating point can be considered a form of scientific notation. A floating-point system can be used to represent, with a fixed number of digits, numbers of very different orders of magnitude — such as the number of meters between galaxies or between protons in an atom. For this reason, floating-poin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single Precision
Single-precision floating-point format (sometimes called FP32 or float32) is a computer number format, usually occupying 32 bits in computer memory; it represents a wide dynamic range of numeric values by using a floating radix point. A floating-point variable can represent a wider range of numbers than a fixed-point variable of the same bit width at the cost of precision. A signed 32-bit integer variable has a maximum value of 231 − 1 = 2,147,483,647, whereas an IEEE 754 32-bit base-2 floating-point variable has a maximum value of (2 − 2−23) × 2127 ≈ 3.4028235 × 1038. All integers with 7 or fewer decimal digits, and any 2''n'' for a whole number −149 ≤ ''n'' ≤ 127, can be converted exactly into an IEEE 754 single-precision floating-point value. In the IEEE 754-2008 standard, the 32-bit base-2 format is officially referred to as binary32; it was called single in IEEE 754-1985. IEEE 754 specifies additional floating-point types, such as 64-bit base-2 ''double prec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debugging
In computer programming and software development, debugging is the process of finding and resolving '' bugs'' (defects or problems that prevent correct operation) within computer programs, software, or systems. Debugging tactics can involve interactive debugging, control flow analysis, unit testing, integration testing, log file analysis, monitoring at the application or system level, memory dumps, and profiling. Many programming languages and software development tools also offer programs to aid in debugging, known as ''debuggers''. Etymology The terms "bug" and "debugging" are popularly attributed to Admiral Grace Hopper in the 1940s. While she was working on a Mark II computer at Harvard University, her associates discovered a moth stuck in a relay and thereby impeding operation, whereupon she remarked that they were "debugging" the system. However, the term "bug", in the sense of "technical error", dates back at least to 1878 and Thomas Edison who describes the "litt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syntactic Sugar
In computer science, syntactic sugar is syntax within a programming language that is designed to make things easier to read or to express. It makes the language "sweeter" for human use: things can be expressed more clearly, more concisely, or in an alternative style that some may prefer. Syntactic sugar is usually a shorthand for a common operation that could also be expressed in an alternate, more verbose, form: The programmer has a choice of whether to use the shorter form or the longer form, but will usually use the shorter form since it is shorter and easier to type and read. For example, many programming languages provide special syntax for referencing and updating array elements. Abstractly, an array reference is a procedure of two arguments: an array and a subscript vector, which could be expressed as get_array(Array, vector(i,j)). Instead, many languages provide syntax such as Array ,j/code>. Similarly an array element update is a procedure consisting of three arguments, for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Mode
In computing, direct or immediate mode in an interactive programming system is the immediate execution of commands, statements, or expressions. In many interactive systems, most of these can both be included in programs or executed directly in a read–eval–print loop (REPL). Most interactive systems also offer the possibility of defining programs in the REPL, either with explicit declarations, such as Python's def, or by labelling them with line numbers. Programs can then be run by calling a named or numbered procedure or by running a main program. Many programming systems, from Lisp and JOSS to Python and Perl have interactive REPLs which also allow defining programs. Most integrated development environment An integrated development environment (IDE) is a software application that provides comprehensive facilities to computer programmers for software development. An IDE normally consists of at least a source code editor, build automation tools ...s offer a direct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command Line
A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and providing information to them as to what actions they are to perform. In some cases the invocation is conditional based on conditions established by the user or previous executables. Such access was first provided by computer terminals starting in the mid-1960s. This provided an interactive environment not available with punched cards or other input methods. Today, many users rely upon graphical user interfaces and menu-driven interactions. However, some programming and maintenance tasks may not have a graphical user interface and use a command line. Alternatives to the command-line interface include text-based user interface menus (for example, IBM AIX SMIT), keyboard shortcuts, and various desktop metaphors centered on the pointer (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McDonnell Douglas
McDonnell Douglas was a major American aerospace manufacturing corporation and defense contractor, formed by the merger of McDonnell Aircraft and the Douglas Aircraft Company in 1967. Between then and its own merger with Boeing in 1997, it produced well-known commercial and military aircraft, such as the DC-10 airliner, the F-15 Eagle air superiority fighter, the MD-80 airliner, and the F/A-18 Hornet multirole fighter. The corporation's headquarters were at St. Louis Lambert International Airport, near St. Louis, Missouri; its subsidiary, McDonnell Douglas Technical Services Company (MDTSC), was based elsewhere in St. Louis County, Missouri. At its peak in mid-1990, McDonnell Douglas employed 132,500 people. By the end of 1992, employment had dropped to approximately 87,400. History Background The company was formed from the firms of James Smith McDonnell and Donald Wills Douglas in 1967. Both men were of Scottish ancestry, were graduates of the Massachusetts Institute of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
