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Action! (programming Language)
Action! is a procedural programming language and integrated development environment written by Clinton Parker for the Atari 8-bit computers. The language, which is similar to ALGOL, compiles to high-performance code for the MOS Technology 6502 of the Atari computers. Action! was distributed on ROM cartridge by Optimized Systems Software starting in 1983. It was one of the company's first bank-switched 16 kB "Super Cartridges". The runtime library is stored in the cartridge; to make a standalone application requires the Action! Toolkit which was sold separately by OSS. Parker, working with Henry Baker, had previously developed Micro-SPL, a systems programming language for the Xerox Alto. Action! is largely a port of Micro-SPL concepts to the Atari with changes to support the 6502 processor and the addition of an integrated fullscreen editor and debugger. Action! was used to develop at least two commercial products—the '' HomePak'' productivity suite and '' Games Compute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optimized Systems Software
Optimized Systems Software (OSS) was a company that produced disk operating systems, programming languages with integrated development environments, and applications primarily for Atari 8-bit computers. The founders of OSS previously developed Atari DOS, Atari BASIC, and the Atari Assembler Editor for Atari, Inc., and many OSS products are substantially improved versions. and DOS XL are based on Atari DOS. BASIC A+, BASIC XL, and BASIC XE are based on Atari BASIC. EASMD and MAC/65 are modeled on the Atari Assembler Editor. Action! is an ALGOL-inspired compiled programming language with an integrated full-screen editor. OSS also sold some software for the Apple II. OSS transitioned to the Atari ST with Personal Pascal and the Mac (computer), Mac with Personal Prolog (which was also advertised for the Atari ST, but may not have been released). OSS was not as significant in those markets. The company merged with ICD in 1988. History Optimized Systems Software was forme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU General Public License
The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first copyleft license available for general use. It was originally written by Richard Stallman, the founder of the Free Software Foundation (FSF), for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. The licenses in the GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. The GPL is more restrictive than the GNU Lesser General Public License, and even more distinct from the more widely used permissive software licenses such as BSD, MIT, and Apache. Historically, the GPL license family has been one of the most popular software licenses in the free and open-source software (FOSS) domai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signedness
In computing, signedness is a property of data types representing numbers in computer programs. A numeric variable is ''signed'' if it can represent both positive and negative numbers, and ''unsigned'' if it can only represent non-negative numbers (zero or positive numbers). As ''signed'' numbers can represent negative numbers, they lose a range of positive numbers that can only be represented with ''unsigned'' numbers of the same size (in bits) because roughly half the possible values are non-positive values, whereas the respective unsigned type can dedicate all the possible values to the positive number range. For example, a two's complement signed 16-bit integer An integer is the number zero (0), a positive natural number (1, 2, 3, ...), or the negation of a positive natural number (−1, −2, −3, ...). The negations or additive inverses of the positive natural numbers are referred to as negative in ... can hold the values −32768 to 32767 inclusively, while an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Type
In computer science and computer programming, a data type (or simply type) is a collection or grouping of data values, usually specified by a set of possible values, a set of allowed operations on these values, and/or a representation of these values as machine types. A data type specification in a program constrains the possible values that an expression, such as a variable or a function call, might take. On literal data, it tells the compiler or interpreter how the programmer intends to use the data. Most programming languages support basic data types of integer numbers (of varying sizes), floating-point numbers (which approximate real numbers), characters and Booleans. Concept A data type may be specified for many reasons: similarity, convenience, or to focus the attention. It is frequently a matter of good organization that aids the understanding of complex definitions. Almost all programming languages explicitly include the notion of data type, though the possible d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atari Assembler Editor
Atari Assembler Editor (sometimes written as Atari Assembler/Editor) is a ROM cartridge-based development system released by Atari, Inc. in 1981. It is used to edit, assemble, and debug 6502 programs for Atari 8-bit computers without the need for additional tools. It was programmed by Kathleen O'Brien of Shepardson Microsystems, the company which wrote Atari BASIC, and Assembler Editor shares many design concepts with that language implementation. Assembly times are slow, making the cartridge challenging to use for larger programs. In the manual, Atari recommended the Assembler Editor as a tool for writing subroutines to speed up Atari BASIC, which would be much smaller than full applications. The Atari Macro Assembler was offered as an alternative with better performance and more features, such as macros, but it is disk-based, copy-protected, and does not include an editor or debugger. Despite the suggestion, commercial software was written using the Assembler Editor, such as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atari BASIC
Atari BASIC is an interpreter for the BASIC programming language that shipped with Atari 8-bit computers. Unlike most American BASICs of the home computer era, Atari BASIC is not a derivative of Microsoft BASIC and differs in significant ways. It includes keywords for Atari-specific features and lacks support for string arrays. The language was distributed as an 8 KB ROM cartridge for use with the 1979 Atari 400 and 800 computers and included the ''Atari BASIC Reference Manual'' written by Carol Shaw and Keith Brewster. Starting with the 600XL and 800XL in 1983, BASIC is built into the system. There are three primary versions of the software: the original cartridge-based "A", the built-in "B" for the 600XL/800XL, and the final "C" version in late-model XLs and the XE series. Despite the Atari 8-bit computers running at a higher speed than most of its contemporaries, several technical decisions placed Atari BASIC near the bottom in performance benchmarks. The original ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recursion
Recursion occurs when the definition of a concept or process depends on a simpler or previous version of itself. Recursion is used in a variety of disciplines ranging from linguistics to logic. The most common application of recursion is in mathematics and computer science, where a function (mathematics), function being defined is applied within its own definition. While this apparently defines an infinite number of instances (function values), it is often done in such a way that no infinite loop or infinite chain of references can occur. A process that exhibits recursion is ''recursive''. Video feedback displays recursive images, as does an infinity mirror. Formal definitions In mathematics and computer science, a class of objects or methods exhibits recursive behavior when it can be defined by two properties: * A simple ''base case'' (or cases) — a terminating scenario that does not use recursion to produce an answer * A ''recursive step'' — a set of rules that reduce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Activation Record
In computer science, a call stack is a stack data structure that stores information about the active subroutines and inline blocks of a computer program. This type of stack is also known as an execution stack, program stack, control stack, run-time stack, or machine stack, and is often shortened to simply the "stack". Although maintenance of the call stack is important for the proper functioning of most software, the details are normally hidden and automatic in high-level programming languages. Many computer instruction sets provide special instructions for manipulating stacks. A call stack is used for several related purposes, but the main reason for having one is to keep track of the point to which each active subroutine should return control when it finishes executing. An active subroutine is one that has been called, but is yet to complete execution, after which control should be handed back to the point of call. Such activations of subroutines may be nested to any level (re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
One-pass Compiler
In computer programming, a one-pass compiler is a compiler that processes each compilation unit only once, sequentially translating each source statement or declaration into something close to its final machine code. This is in contrast to a multi-pass compiler which converts the program into one or more intermediate representations in steps between source code and machine code, and which reprocesses the entire compilation unit in each sequential pass. A one-pass compiler initially has to leave addresses for forward jumps unresolved. These can be handled in various ways (e.g. tables of forward jumps and targets) without needing to have another complete pass. Some nominally one-pass compilers effectively 'pass the buck' by generating assembly language and letting the assembler sort out the forward references, but this requires one or more passes in the assembler. One-pass compilers are smaller and faster than multi-pass compilers. One-pass compilers are unable to generate as eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opcode
In computing, an opcode (abbreviated from operation code) is an enumerated value that specifies the operation to be performed. Opcodes are employed in hardware devices such as arithmetic logic units (ALUs), central processing units (CPUs), and software instruction sets. In ALUs, the opcode is directly applied to circuitry via an input signal bus. In contrast, in CPUs, the opcode is the portion of a machine language instruction that specifies the operation to be performed. CPUs Opcodes are found in the machine language instructions of CPUs as well as in some abstract computing machines. In CPUs, an opcode may be referred to as an instruction machine code, instruction code, instruction syllable, instruction parcel, or opstring. For any particular processor (which may be a general CPU or a more specialized processing unit), the opcodes are defined by the processor's instruction set architecture (ISA). They can be described using an opcode table. The types of operations may in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machine Code Monitor
A machine code monitor ( machine language monitor) is software that allows a user to enter commands to view and change memory address, memory locations on a computer, with options to load and save memory contents from/to secondary storage. Some full-featured machine code monitors provide detailed control ("single-stepping") of the execution of machine language programs (much like a debugger), and include absolute-address Assembly language#Assembler, code assembly and disassembler, disassembly capabilities. Motorola published the MIKBUG ROM monitor for the 6800 in 1973 and the BUFFALO ROM monitor for the Motorola 68HC11, 68HC11. Machine code monitors became popular during the home computer era of the 1970s and 1980s and were sometimes available as resident firmware in some computers (e.g., the built-in monitors in the Commodore 128, Zenith Z-89, Heathkit H89 and Zenith laptops). Often, computer manufacturers rely on their ROM-resident monitors to permit users to reconfigure their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bank Switch
Bank switching is a technique used in computer design to increase the amount of usable memory beyond the amount directly addressable by the processor instructions. It can be used to configure a system differently at different times; for example, a ROM required to start a system from diskette could be switched out when no longer needed. In video game systems, bank switching allowed larger games to be developed for play on existing consoles. Bank switching originated in minicomputer systems. Many modern microcontrollers and microprocessors use bank switching to manage random-access memory, non-volatile memory, input-output devices and system management registers in small embedded systems. The technique was common in 8-bit microcomputer systems. Bank-switching may also be used to work around limitations in address bus width, where some hardware constraint prevents straightforward addition of more address lines, and to work around limitations in the ISA, where the addresses gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
