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DB48X
RPL is a handheld calculator operating system and application programming language used on Hewlett-Packard's scientific graphing RPN (Reverse Polish Notation) calculators of the HP 28, 48, 49 and 50 series, but it is also usable on non-RPN calculators, such as the 38, 39 and 40 series. Internally, it was also utilized by the 17B, 18C, 19B and 27S. RPL is a structured programming language based on RPN, but equally capable of processing algebraic expressions and formulae, implemented as a threaded interpreter. RPL has many similarities to Forth, both languages being stack-based, as well as the list-based LISP. Contrary to previous HP RPN calculators, which had a fixed four-level stack, the dynamic stack used by RPL is only limited by available RAM, with the calculator displaying an error message when running out of memory rather than silently dropping arguments off the stack as in fixed-sized RPN stacks. RPL originated from HP's Corvallis, Oregon development f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic RPN Stack
Reverse Polish notation (RPN), also known as reverse Łukasiewicz notation, Polish postfix notation or simply postfix notation, is a mathematical notation in which operators ''follow'' their operands, in contrast to prefix or Polish notation (PN), in which operators ''precede'' their operands. The notation does not need any parentheses for as long as each operator has a fixed number of operands. The term ''postfix notation'' describes the general scheme in mathematics and computer sciences, whereas the term ''reverse Polish notation'' typically refers specifically to the method used to enter calculations into hardware or software calculators, which often have additional side effects and implications depending on the actual implementation involving a stack. The description "Polish" refers to the nationality of logician Jan Łukasiewicz, who invented Polish notation in 1924. The first computer to use postfix notation, though it long remained essentially unknown outside of Ger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP 50g
The HP 49/50 series are Hewlett-Packard (HP) manufactured graphing calculators. They are the successors of the HP 48 series. There are five calculators in the 49/50 series of HP graphing calculators. These calculators have both algebraic and RPN entry modes, and can perform numeric and symbolic calculations using the built-in Computer Algebra System (CAS), which is an improved ALG48 and Erable combination from the HP 48 series. It is widely considered the greatest calculator ever designed for engineers, scientists, and surveyors. It has advanced functions suitable for applications in mathematics, linear algebra, physics, statistical analysis, numerical analysis, computer science, and others. Although out of production, its popularity has led to high prices on the used market. HP 49G The HP 49G (F1633A, F1896A), was released in August 1999. The 49G incorporated many of the most powerful interface and mathematics tools available on the HP 48 series into the fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP48G
The HP 48 is a series of graphing calculators designed and produced by Hewlett-Packard from 1990 until 2003. The series includes the HP 48S, HP 48SX, HP 48G, HP 48GX, and HP 48G+, the G models being expanded and improved versions of the S models. The models with an X suffix are expandable via special RAM (memory expansion) and ROM (software application) cards. In particular, the GX models have more onboard memory than the G models. The G+ models have more onboard memory only. The SX and S models have the same amount of onboard memory. Note that the similarly named hp 48gII (2004) is not a member of the series but closely related to the HP 49/50 series, HP 49g+. The calculators use Reverse Polish Notation (RPN) and the RPL (programming language), RPL programming language. The computer architecture, hardware architecture developed for the HP 48 series became the basis for the HP 38G, with a simplified user interface and an infix notati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Threaded Code
In computer science, threaded code is a programming technique where the code has a form that essentially consists entirely of calls to subroutines. It is often used in compilers, which may generate code in that form or be implemented in that form themselves. The code may be processed by an interpreter or it may simply be a sequence of machine code call instructions. Threaded code has better density than code generated by alternative generation techniques and by alternative calling conventions. In cached architectures, it may execute slightly slower. However, a program that is small enough to fit in a computer processor's cache may run faster than a larger program that suffers many cache misses. Small programs may also be faster at thread switching, when other programs have filled the cache. Threaded code is best known for its use in many compilers of programming languages, such as Forth, many implementations of BASIC, some implementations of COBOL, early versions of B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LISP
Lisp (historically LISP, an abbreviation of "list processing") is a family of programming languages with a long history and a distinctive, fully parenthesized Polish notation#Explanation, prefix notation. Originally specified in the late 1950s, it is the second-oldest high-level programming language still in common use, after Fortran. Lisp has changed since its early days, and many Programming language dialect, dialects have existed over its history. Today, the best-known general-purpose Lisp dialects are Common Lisp, Scheme (programming language), Scheme, Racket (programming language), Racket, and Clojure. Lisp was originally created as a practical mathematical notation for computer programs, influenced by (though not originally derived from) the notation of Alonzo Church's lambda calculus. It quickly became a favored programming language for artificial intelligence (AI) research. As one of the earliest programming languages, Lisp pioneered many ideas in computer science, includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random-access Memory
Random-access memory (RAM; ) is a form of Computer memory, electronic computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A random-access memory device allows data items to be read (computer), read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks and Magnetic tape data storage, magnetic tape), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement. In today's technology, random-access memory takes the form of integrated circuit (IC) chips with MOSFET, MOS (metal–oxide–semiconductor) Memory cell (computing), memory cells. RAM is normally associated with Volatile memory, volatile types of memory where s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP-27S
The HP-27S was a pocket calculator produced by Hewlett-Packard, introduced in 1988, and discontinued between 1990 and 1993 (sources vary). It was the first HP scientific calculator to use algebraic entry instead of RPN, and though it was labelled ''scientific'', it also included features associated with specialized business calculators. The device featured standard scientific functions, including statistics and probability. Equations could be stored in memory, and solved and integrated for specified variables. Binary, octal, and hexadecimal number bases could be used. Business features included a real-time clock and calendar with up to ten appointments (each with a 22 character message string), as well as functions such as time value of money calculations. The 27S was not programmable in the conventional way, but it included an advanced formula-storage system with programming features. Within stored formulas, sub-formulas could be defined and later referred to by name. Loops ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
