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Macintosh 512K
The Macintosh 512K is a personal computer that was designed, manufactured and sold by Apple Computer from September 1984 to April 1986. It is the first update to the original Macintosh 128K. It was virtually identical to the previous Macintosh, differing primarily in the amount of built-in random-access memory. The increased memory turned the Macintosh into a more business-capable computer and gained the ability to run more software. It is the earliest Macintosh model that can be used as an AppleShare server and, with a bridge Mac, communicate with modern devices. The Mac 512K originally shipped with Macintosh System 1.1 but was able to run all versions of Mac OS up to System 4.1. It was replaced by the Macintosh 512Ke and the Macintosh Plus. All support for the Mac 512K was discontinued on September 1, 1998. Features Processor and memory Like the Macintosh 128K before it, the 512K contained a Motorola 68000 connected to 512 KB of DRAM by a 16-bit data bus. Though t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Computer
Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company by market capitalization, the fourth-largest personal computer vendor by unit sales and second-largest mobile phone manufacturer. It is one of the Big Five American information technology companies, alongside Alphabet, Amazon, Meta, and Microsoft. Apple was founded as Apple Computer Company on April 1, 1976, by Steve Wozniak, Steve Jobs and Ronald Wayne to develop and sell Wozniak's Apple I personal computer. It was incorporated by Jobs and Wozniak as Apple Computer, Inc. in 1977 and the company's next computer, the Apple II, became a best seller and one of the first mass-produced microcomputers. Apple went public in 1980 to instant financial success. The company developed computers featuring innovative graphical user interfaces, in ... [...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 trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel 80186
The Intel 80186, also known as the iAPX 186, or just 186, is a microprocessor and microcontroller introduced in 1982. It was based on the Intel 8086 and, like it, had a 16-bit external data bus multiplexed with a 20-bit address bus. The 80188 variant, with an 8-bit external data bus was also available. Description The 80186 series was generally intended for embedded systems, as microcontrollers with external memory. Therefore, to reduce the number of integrated circuits required, it included features such as clock generator, interrupt controller, timers, wait state generator, DMA channels, and external chip select lines. The initial clock rate of the 80186 was 6 MHz, but due to more hardware available for the microcode to use, especially for address calculation, many individual instructions completed in fewer clock cycles than on an 8086 at the same clock frequency. For instance, the common ''register+immediate'' addressing mode was significantly faster than on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LaserWriter
The LaserWriter is a laser printer with built-in PostScript interpreter sold by Apple, Inc. from 1985 to 1988. It was one of the first laser printers available to the mass market. In combination with WYSIWYG publishing software like PageMaker, that operated on top of the graphical user interface of Macintosh computers, the LaserWriter was a key component at the beginning of the desktop publishing revolution.H. A. Tucker: Desktop Publishing.'' In: Maurice M. de Ruiter: ''Advances in Computer Graphics III.'' Springer, 1988, , P. 296.Michael B. Spring: Electronic printing and publishing: the document processing revolution.'' CRC Press, 1991, , Page 46. History Development of laser printing Laser printing traces its history to efforts by Gary Starkweather at Xerox in 1969, which resulted in a commercial system called the Xerox 9700. IBM followed this with the IBM 3800 system in 1976. Both machines were large, room-filling devices handling the combined output of many users.Benji ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Multitasking
In computing, multitasking is the concurrent execution of multiple tasks (also known as processes) over a certain period of time. New tasks can interrupt already started ones before they finish, instead of waiting for them to end. As a result, a computer executes segments of multiple tasks in an interleaved manner, while the tasks share common processing resources such as central processing units (CPUs) and main memory. Multitasking automatically interrupts the running program, saving its state (partial results, memory contents and computer register contents) and loading the saved state of another program and transferring control to it. This " context switch" may be initiated at fixed time intervals (pre-emptive multitasking), or the running program may be coded to signal to the supervisory software when it can be interrupted (cooperative multitasking). Multitasking does not require parallel execution of multiple tasks at exactly the same time; instead, it allows more than o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multifinder
MultiFinder is an extension for the Apple Macintosh's classic Mac OS, introduced on August 11, 1987 and included with System Software 5. It adds cooperative multitasking of several applications at once – a great improvement over the previous Macintosh systems, which can only run one application at a time. With the advent of System 7, MultiFinder became a standard integrated part of the operating system and remained until the introduction of Mac OS X. History Background The first Macintosh was released in 1984, and Apple's developers made an early decision that the machine's 128 KB of RAM was so limited that they must abandon the application multitasking functionality that Apple had developed for the Lisa. As the successive Macintosh hardware models were released with much more RAM being the key feature, new programming techniques were developed as workarounds to allow users to run concurrent applications. Desk Accessories became a staple through the lifespan of System 6; a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft Excel
Microsoft Excel is a spreadsheet developed by Microsoft for Microsoft Windows, Windows, macOS, Android (operating system), Android and iOS. It features calculation or computation capabilities, graphing tools, pivot tables, and a macro (computer science), macro programming language called Visual Basic for Applications (VBA). Excel forms part of the Microsoft Office suite of software. Features Basic operation Microsoft Excel has the basic features of all spreadsheets, using a grid of ''cells'' arranged in numbered ''rows'' and letter-named ''columns'' to organize data manipulations like arithmetic operations. It has a battery of supplied functions to answer statistical, engineering, and financial needs. In addition, it can display data as line graphs, histograms and charts, and with a very limited three-dimensional graphical display. It allows sectioning of data to view its dependencies on various factors for different perspectives (using ''pivot tables'' and the ''sce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pascal Programming Language
Pascal is an Imperative programming, imperative and Procedural programming, procedural programming language, designed by Niklaus Wirth as a small, efficient language intended to encourage good programming practices using structured programming and data structure, data structuring. It is named in honour of the French mathematician, philosopher and physicist Blaise Pascal. Pascal was developed on the pattern of the ALGOL 60 language. Wirth was involved in the process to improve the language as part of the ALGOL X efforts and proposed a version named ALGOL W. This was not accepted, and the ALGOL X process bogged down. In 1968, Wirth decided to abandon the ALGOL X process and further improve ALGOL W, releasing this as Pascal in 1970. On top of ALGOL's variable (computer science), scalars and array data type, arrays, Pascal enables defining complex datatypes and building dynamic and recursive data structures such as list (abstract data type), lists, tree (data structure), trees and gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacProject
MacProject was a project management and scheduling business application released along with the first Apple Macintosh systems in 1984. MacProject was one of the first major business tools for the Macintosh which enabled users to calculate the "critical path" to completion and estimate costs in money and time. If a project deadline was missed or if available resources changed, MacProject recalculated everything automatically. MacProject was written by Debra Willrett at Solosoft, and was published and distributed by Apple Computer to promote the original Macintosh personal computer. It was developed from an earlier application written by Debra Willrett for Apple's Lisa computer, LisaProject. This was the first graphical user interface (GUI) for project management. There were many other project management applications on the market at the time, but LisaProject was the first to simplify the process by allowing the user to interactively draw their project on the computer in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacDraw
MacDraw is a discontinued vector graphics drawing application released along with the first Apple Macintosh systems in 1984. MacDraw was one of the first WYSIWYG drawing programs that could be used in collaboration with MacWrite. It was eventually adapted by Claris and, in the early 1990s, MacDraw Pro was released with color support. MacDraw was the vector cousin of MacPaint. In the preface of the third edition of ''Introduction to Algorithms'', the authors make an emphatic plea for the creation of an OS X-compatible version of MacDraw Pro. Early versions MacDraw was based on Apple's earlier program, LisaDraw, which was developed for the Apple Lisa computer which was released in 1983. LisaDraw and MacDraw were developed by the same person, Mark Cutter. The first version of MacDraw was similar to that of MacPaint, featuring both the same tools and patterns. However MacDraw is vector-based, meaning that an object's properties and placement can be changed at any time. MacDraw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
