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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.


• Photo-realistic look based on an existing device
• 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, extended 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
• Double-tap display to show stack and all memory registers
• Complex numbers may be used in almost all operations
• Non-volatile stack registers
• 18 non-volatile memory registers (9 for complex numbers)
• Exponentiation and faculty accept any values
• Hyperbolic functions
• Solve linear equations in two or three unknowns
• Solve quadratic and cubic equations in one unknown
• 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 in the past or future
• Number of days between any two dates; support for Julian dates
• Last Stack
• Convert display value to hexadecimal
• Percentage of sum
• Register arithmetic includes sum registers and LAST x
• Indicators for active prefix keys
• Angular mode indicator
• Localized decimal point

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 (iPad version):

"This is by far the best RPN calculator available for the iPad!"

"Great app that I would recommend to anyone who grew up with an HP-45!"

"Calculator works great just like my original HP-45. Worth the price and brings back memories of using the slide rule before getting my HP-45."

"This is one of the most accurate but also nicest looking emulators I have come across for the HP-45, or any vintage HP calculator for that matter."

"With the Super-45 mode functions that were added by the developer, this is an extremely powerful calculator. Very elegant design."

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What's New

• Better FRAC results for large arguments

Bug fix:

• RND didn't round correctly certain values in SCI and ENG mode

My Rating

App Store Rating