RPN-70 HD3.4 - App Store

RPN-70 HD is a complete, photo-realistic simulation of the financial hand-held calculator HP-70 from 1974. It handles loan amortization, saving plans, depreciation, and much more with ease.

What users said:

"Hard to find a decent calculator on iPad, try this one."

"I don't normally write reviews but RPN-70 is just too fantastic to not get excited about. Apple should list this app under their Education category in the App Store and make it a must have for every college bound student. It is the best HP emulator in the market."

"An incredibly well-engineered calculator app, and free, to boot!"

"This is a really cool Financial calculator. Just like using the original HP-70. Accurate to the penny."
Features:

. Photo-realistic look based on an existing device
. "Live" register view in landscape mode
. Animated keys with click sound (adjustable volume)
. All functions and operations of the HP-70 fully implemented
. Simulation of the HP-70's computation time (optional)
. Correct wrong number entries by swiping left across the display
. Cut/copy/paste of display value
. Visual indicators keep track of stored input parameters (optional)
. Stack shown right below display (optional)
. 10 non-volatile memory registers (optional)
. Built-in short manual with many examples

The HP-70 was discontinued after just one year. It is one of the rarest calculators, hard to find in any condition.

NOTE:
RPN-70 HD is a faithful simulation of a vintage HP-70 calculator, as has been verified against a real device using the examples in the Applications Cookbook section of the HP-70 manual. In certain cases, what may appear like a bug of the app is actually an idiosyncrasy of the HP-70.

IMPORTANT: The HP-70 requires exactly three input parameters from the top-row keys, at least one of them being either "n" or "i". In other words, you can't use PMT, PV, and FV as input parameters simultaneously.

A version for the iPhone named "RPN-70 SD" is also available.

Visit the website: www.cuveesoft.ch

Version History • All registers are now non-volatile.

• Double-tapping the display acts like the View/Registers button (bottom-right).

• Triple-tapping the display:
- Clears registers R0..R9 (only if enabled in Settings).
- Resets the register K to 12. 3.4 07/28/2025 • Faster startup – no delay until the first button press is recognized after switching on. 3.3 05/09/2025 • RPN-70 HD runs on Apple Silicon Macs (see notes on homepage cuveesoft.ch).

• Disabled low-battery indicator (all decimal points lit) when running on Apple Silicon Mac.

• RPN-70 HD requires iOS 12 or later. 3.2 11/07/2024 • iPadOS 16 compatibility 3.1.5 11/09/2022 • iPad mini (2021) compatibility 3.1.2 10/03/2021 • Suppressed clipboard notification on each keypress (iOS 14)
Bug Fix:

• An empty clipboard could cause a crash on startup (iOS 14) 3.1.1 04/15/2021 • Key flashing may be turned off and on:
- Select desired mode in "Settings"
or:
- Store 19390101 in M (STO M) or R1 (STO 1) to turn off
- Recall 19390101 from M (M) or R1 (STO.1) to turn on
(Hewlett-Packard Company was founded an Jan 1, 1939)
Bug Fixes:

• Registers in portrait mode didn't show correctly in Dark Mode

• Using scientific notation could crash the app in some regions, e.g. Australia, Sweden, Slovenia. 3.1 04/01/2020 • Support for iOS 13
RPN-70 HD now requires iOS 11 or later. 3.0 01/24/2020 • The register window now shows selected input parameters (n,i,PMT,PV,FV) in green

• Changed "Undo digit" sound to same as found in other CuVee calculators

• Tapping the register view in portrait mode reveals registers 0 to 9

• Many under-the-hood refinements 2.7 01/10/2019 • Entering very large numbers automatically shows exponent 2.6 05/04/2017 This update requires iOS 8 or later.

• Calculator sounds mix with background audio and have their own volume control
Bug fixes:

• Fixed a possible crash on startup 2.5 10/02/2016 • Decimal addition/subtraction for higher precision 2.4 07/27/2016 • If audio is playing on start-up, RPN-67 will not produce any sounds 2.2 09/02/2015 • HP-70 low-battery warning (all decimal points lit) if iPad's battery drops below 5%

• Improved sound volume control

• 64-bit support 2.1 02/17/2015 • Landscape mode (finally...)
• 10 optional non-volatile memory registers
• Name change to better match the iPhone version (RPN-70 SD) 2.0 11/26/2013 • Full-screen display
• Compatible with iOS 7
• Requires iOS 5.1 or later

Bug fixes:
• Fixed pasting values dropping decimal point in certain regions 1.1 09/14/2013 • Improved keyboard response - no more missed keys
• Selectable keyclick volume (off/soft/loud)

Note that the volume is also affected by the device settings ("Settings - General - Sounds - Ringer and Alerts"). 1.0.3 06/11/2012 • While entering a number, the X register of the stack display reflects the main display
• Improved responsiveness of keyboard
• Tapping the display shows registers or turns the calculator on
• Tapping the register display hides it
• Triple-tapping the display turns the calculator off
• Support for Retina display 1.0.2 05/18/2012 1.0.1 05/17/2011