RPN vs DB40X

RPN-45 SD is a complete simulation of the scientific hand-held calculator HP-45 from 1973. Powerful enhancements turn the calculator into an amazingly useful tool for the 21st century. Features: • Photo-realistic look based on an existing device • Original LED display or high-contrast LCD display • Printer to keep a record of calculations • Animated keys with adjustable click sound and visual feedback • Simulation of the HP-45's computation times (may be disabled) • All functions and operations of the HP-45 fully implemented • "Secret" stopwatch implemented, extensible from 12 to 100 hours capacity • Stopwatch may be preset to current time • Swipe left across display to correct wrong number entries • Cut/copy/paste of display value • Tap display to show stack and all memory registers • Complex numbers may be used in almost all operations • Non-volatile stack and registers • 18 storage locations (9 in complex number mode) • Exponentiation and factorial accept any values (incl. complex) • Optional hyperbolic functions • Logarithm to any base (incl. complex) • Solve linear equations in two or three unknowns • Solve quadratic and cubic equations • Normal distribution, Pearson correlation coefficient of paired variables • Linear regression with estimates • Weighted mean • Permutation, Combination (binomial coefficient) • Integer and fractional part of a number • Display rounding • Random numbers in any range, integer or real • Day of the week of any date between Jan 1, 0001 and Dec 31, 9999 • Easter date for any year between 1583 and 4099 • Support for Julian dates • Date and day of the week a number of days away (past or future) • Number of days between any two dates • Last Stack operation • Show display value in hexadecimal • Percentage of sum • Register arithmetic includes summation registers and LAST x • Indicators for active prefix keys • Angular mode indicator • Localized decimal point • Thousand's separator • Clear all registers • Backup registers in a protected area Double-tap the display for some basic hints. Also available for iPad (RPN-45 HD). For more information, a manual and sample calculations visit the RPN-45 website: cuveesoft.ch/rpn45/en What users said: "Have been using HP RPN calculators since HP-35 first came out. The CuVée versions for Apple products are the best emulations by far. I have, and regularly use, them all." "This app is a great emulator of the classic HP-45 Scientific Calculator, in look, feel and function. It keeps getting better and better with each update." "This is the most like the real thing that I've used. I've bought others but keep coming back to this App. It's photorealistic, the LEDs appear the way the real ones do, and the buttons almost give the same satisfying feedback of the real thing."

DB40X is a high-precision scientific calculator compatible with DB48X and inspired by the legendary HP48 series from Hewlett-Packard. It is not an emulator, but a redesign from scratch, which is faster, and delivers never seen before capabilities like computations in arbitrary precision. Like the original HP48, DB40X supports an unlimited stack, RPN and algebraic operations, complex numbers, based numbers, vectors, matrices, text, symbolic computations, numerical solving and integration, graphing and plotting, statistics, engineering units, and well over 1000 built-in functions. DB40X adds several HP50G capabilities, including a library of equations and constants covering mathematics, physics or chemistry. Using modern technologies, DB40X goes well beyond the original HP48 in many ways: - It is significantly faster, uses less memory, and features a higher-resolution 240x400 pixels graphical display. - Integer and decimal values can have an arbitrarily large number of digits, so you can compute log(pi) with 200 digits in a few keystrokes. - The six function keys feature up to three function per key, giving quick access to up to 18 related functions at a time. - Complex numbers can mix and match polar and rectangular form. - Symbolic operations extend to complex numbers, vectors and matrices. - Based numbers can be in any base from 2 to 36, and support any number of bits, making it easy to emulate a 23-bit or 512-bit processor. - Text is represented using Unicode instead of the proprietary HP encoding, facilitating data exchange with the rest of the world. - Multiple graphs can be distinguished using bitmap patterns. - Engineering units include all the modern evolutions of the SI system, and can be configured by the user, e.g. to integrate currency units with the exchange rate du jour. Converting between USD/hour and EUR/day has never been so easy! - A built-in hyperlinked help system documents functions simply by holding the corresponding key, and combine a quick start guide, a user manual and a reference manual. DB40X will run many user RPL programs as is. However, since it is not an emulator, it will not run any HP binary object, and notably will not run HP48 games or anything involving system RPL. Version 0.7.14 is an early-access release. Please consult https://github.com/c3d/db48x/blob/stable/doc/5-Unimplemented.md for a list of HP48 commands that are not yet implemented. DB40X is part of a family of compatible RPL calculators that include DB48X and DB50X. DB40X lacks the ability to write programs or data to disk, and RPL programs are limited to 40K.