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Hp-45
The HP-45 is the second scientific pocket calculator introduced by Hewlett-Packard, adding to the features of the HP-35. It was introduced in 1973 with an MSRP of US$395 (). Especially noteworthy was its pioneering addition of a shift key that gave other keys alternate functions. The calculator was code-named ''Wizard'', which is the first known use of a code name for a calculator. It also contained an Easter egg that allowed users to access a not-especially accurate stopwatch mode. An accurate version of the stopwatch mode was officially featured in the 1975 successor of the HP-45, the HP-55. The display of the HP-45 hidden timer showing 00 hours 00 minutes 07 seconds and 58/100 second. Emulators Several individuals and companies make software emulators of the HP 45 series calculators. Nonpareil, high-fidelity simulator for calculators Emulates, among other, the HP-45. Licensed under the GNU General Public License (GPL). Available for Microsoft Windows. HP-45 Emulator ...
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Scientific Calculator
A scientific calculator is an electronic calculator, either desktop or handheld, designed to perform mathematical operations. They have completely replaced slide rules and are used in both educational and professional settings. In some areas of study scientific calculators have been replaced by graphing calculators and financial calculators which have the capabilities of a scientific calculator along with the capability to graph input data. Functions When scientific calculators were originally marketed they normally had only four of five capabilities (addition, subtraction, multiplication, division and square root). Modern scientific calculators generally have many more capabilities than the original four or five function calculator, and the capabilities differ between manufacturers and models. The capabilities of a modern scientific calculator include: * scientific notation * floating-point decimal arithmetic * logarithmic functions, using both base 10 and base e ...
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HP-55
The HP-55 was a programmable handheld calculator; a lower-cost alternative to the HP-65. Introduced by Hewlett-Packard in 1975, it featured twenty storage registers and room for 49 keystroke instructions. Its outward appearance was similar to the HP-65, but its silver band went through between the display and the keyboard like HP-45, its some key functions were different from HP-65 and it did not have a magnetic card reader/writer. Like all Hewlett-Packard calculators of the era and most since, the HP-55 used Reverse Polish Notation (RPN) and a four-level automatic operand stack. Another feature of the HP-55 was that it officially featured a stop-watch function much similar to the hidden stop-watch function of the earlier HP-45 calculator. This stop-watch function could be accessed by setting the mode-slider to the Timer position. A quartz-crystal inside the calculator provided an accurate timebase, and it was advertised that the timer ran with as little as +/- 0.01% error. T ...
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Windows Phone 7
Windows Phone 7 is the first release of the Windows Phone mobile client operating system, released worldwide on October 21, 2010, and in the United States on November 8, 2010. It runs on the Windows CE 6.0 kernel. It received multiple large updates, the last being Windows Phone 7.8, which was released in January 2013 and added a few features backported from Windows Phone 8, such as a more customizable start screen. Microsoft ended support for Windows Phone 7 on October 14, 2014. It was succeeded by Windows Phone 8, which was released on October 29, 2012. History Microsoft officially unveiled the new operating system, Windows Phone 7 Series, at the Mobile World Congress in Barcelona on February 15, 2010, and revealed additional details at MIX 2010 on March 15, 2010. The final SDK was made available on September 16, 2010. HP later decided not to build devices for Windows Phone, citing that it wanted to focus on devices for its newly purchased webOS. As its original name wa ...
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Symbian
Symbian is a discontinued mobile operating system (OS) and computing platform designed for smartphones. It was originally developed as a proprietary software OS for personal digital assistants in 1998 by the Symbian Ltd. consortium. Symbian OS is a descendant of Psion's EPOC, and was released exclusively on ARM processors, although an unreleased x86 port existed. Symbian was used by many major mobile phone brands, like Samsung, Motorola, Sony Ericsson, and above all by Nokia. It was also prevalent in Japan by brands including Fujitsu, Sharp and Mitsubishi. As a pioneer that established the smartphone industry, it was the most popular smartphone OS on a worldwide average until the end of 2010, at a time when smartphones were in limited use, when it was overtaken by iOS and Android. It was notably less popular in North America. The Symbian OS platform is formed of two components: one being the microkernel-based operating system with its associated libraries, and the oth ...
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Android (operating System)
Android is a mobile operating system based on a modified version of the Linux kernel and other open-source software, designed primarily for touchscreen mobile devices such as smartphones and tablets. Android is developed by a consortium of developers known as the Open Handset Alliance and commercially sponsored by Google. It was unveiled in November 2007, with the first commercial Android device, the HTC Dream, being launched in September 2008. Most versions of Android are proprietary. The core components are taken from the Android Open Source Project (AOSP), which is free and open-source software (FOSS) primarily licensed under the Apache License. When Android is installed on devices, the ability to modify the otherwise free and open-source software is usually restricted, either by not providing the corresponding source code or by preventing reinstallation through technical measures, thus rendering the installed version proprietary. Most Android devices ship with addition ...
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GPL 3
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general use and was originally written by the founder of the Free Software Foundation (FSF), Richard Stallman, for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. These GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. It is more restrictive than the Lesser General Public License and even further distinct from the more widely used permissive software licenses 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 domain. Prominent free software programs licensed under the GPL include the Linux kern ...
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Java (programming Language)
Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers ''write once, run anywhere'' ( WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as reflection and runtime code modification) that are typically not available in traditional compiled languages. , Java was one of the most popular programming languages in use according to GitHub, particularly for client–server web applications, with a reported 9 million developers. Java was originally develo ...
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Microsoft Windows
Windows is a group of several Proprietary software, proprietary graphical user interface, graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for servers, and Windows IoT for embedded systems. Defunct Windows families include Windows 9x, Windows Mobile, and Windows Phone. The first version of Windows was released on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUIs). Windows is the most popular desktop operating system in the world, with Usage share of operating systems, 75% market share , according to StatCounter. However, Windows is not the most used operating system when including both mobile and desktop OSes, due to Android (operating system), Android's massive growth. , the most recent version of Windows is Windows 11 for consumer Personal compu ...
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GNU General Public License
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general use and was originally written by the founder of the Free Software Foundation (FSF), Richard Stallman, for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. These GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. It is more restrictive than the Lesser General Public License and even further distinct from the more widely used permissive software licenses 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 domain. Prominent free software programs licensed under the GPL include the L ...
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HP-45 (101587990)
The HP-45 is the second scientific pocket calculator introduced by Hewlett-Packard, adding to the features of the HP-35. It was introduced in 1973 with an MSRP of US$395 (). Especially noteworthy was its pioneering addition of a shift key that gave other keys alternate functions. The calculator was code-named ''Wizard'', which is the first known use of a code name for a calculator. It also contained an Easter egg that allowed users to access a not-especially accurate stopwatch mode. An accurate version of the stopwatch mode was officially featured in the 1975 successor of the HP-45, the HP-55. The display of the HP-45 hidden timer showing 00 hours 00 minutes 07 seconds and 58/100 second. Emulators Several individuals and companies make software emulators of the HP 45 series calculators. Nonpareil, high-fidelity simulator for calculators Emulates, among other, the HP-45. Licensed under the GNU General Public License (GPL). Available for Microsoft Windows. HP-45 Emulator ...
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Stopwatch
A stopwatch is a timepiece designed to measure the amount of time that elapses between its activation and deactivation. A large digital version of a stopwatch designed for viewing at a distance, as in a sports stadium, is called a stop clock. In manual timing, the clock is started and stopped by a person pressing a button. In fully automatic time, both starting and stopping are triggered automatically, by sensors. The timing functions are traditionally controlled by two buttons on the case. Pressing the top button starts the timer running, and pressing the button a second time stops it, leaving the elapsed time displayed. A press of the second button then resets the stopwatch to zero. The second button is also used to record ''split times'' or ''lap times''. When the split time button is pressed while the watch is running it allows the elapsed time to that point to be read, but the watch mechanism continues running to record total elapsed time. Pressing the split button a ...
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RPN Input Mode
There are various ways in which calculators interpret keystrokes. These can be categorized into two main types: * On a single-step or immediate-execution calculator, the user presses a key for each operation, calculating all the intermediate results, before the final value is shown. * On an expression or formula calculator, one types in an expression and then presses a key, such as "=" or "Enter", to evaluate the expression. There are various systems for typing in an expression, as described below. Immediate execution The immediate execution mode of operation (also known as single-step, algebraic entry system (AES) or chain calculation mode) is commonly employed on most general-purpose calculators. In most simple four-function calculators, such as the Windows calculator in Standard mode and those included with most early operating systems, each binary operation is executed as soon as the next operator is pressed, and therefore the order of operations in a mathematical expression ...
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