RPN-70 SD3.4.1 - App Store

RPN-70 SD is a complete 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:

"Looks good, all functions you need. Love it!"

"This is a beautiful emulation of a very rare HP financial calculator from 1974. Works just like the original but better! Faster, more accurate, with 10 more storage registers, and a popup window lets you see the contents of each stack, financial and storage register. Provides TVM4 functionality for compound interest as well as accumulated simple interest. A true work of art!"

Features:
. Photo-realistic look based on an existing device
. Animated keys with click sound (adjustable volume)
. All functions and operations of the HP-70 fully implemented
. Correct wrong number entries by swiping across the display
. Cut/copy/paste of display value
. Double-tap display to view the stack and memory registers
. Visual indicators keep track of input parameters entered
. 10 non-volatile memory registers (not available in original HP-70)

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 SD 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 HD" is also available.

Short manual and sample calculations on the website: www.cuveesoft.ch

Version History • Improved compatibility with iPhone Air and iOS 26. 3.4.1 10/17/2025 • All registers are now non-volatile.

• Triple-tapping the display:
- Clears the stack, the financial registers, and register M.
- 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 • Disabled low-battery indicator (all decimal points lit) when running on Apple Silicon Mac.

• Visual adjustments to iPhone 16 Pro and iPhone 16 Pro Max.

• RPN-70 SD requires iOS 12 or later. 3.2 11/07/2024 Compatibility with iPhone 14 Pro 3.1.5 09/22/2022 Compatibility with iPhone 12 3.1.1 11/05/2020 • Key flashing may be turned off and on:
- Store 19390101 in R1 to turn off
- Recall 19390101 from R1 to turn on
(Hewlett-Packard Company was founded an Jan 1, 1939)
Bug Fix:

• Using scientific notation could crash the app in some regions, e.g. Australia, Sweden, Slovenia. 3.1 04/01/2020 • iOS 13 compatibility

• Dismiss register view by dragging view down (iOS 13)
RPN-70 SD now requires iOS 11 or later. 3.0 01/24/2020 • In register view, selected input parameters (n,i,PMT,PV,FV) are now colored green

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

• 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 Fix:

• Fixed a possible crash on startup 2.5 10/02/2016 • Decimal addition/subtraction for higher precision 2.4 07/27/2016 • Key-click volume is now stored in settings
Bug Fix:
• Fixed display formatting not corresponding to real HP-70 in certain cases 2.3 07/05/2016 • If audio is playing on start-up, RPN-70 SD 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%

• Sound volume control

• 64-bit support
Bug Fixes:
• Calculator didn't turn itself on automatically (iOS 8 only) 2.1 02/17/2015 iOS 8 users: If the calculator fails to turn itself on, tap the display once.
• 10 non-volatile memory registers 2.0 11/26/2013 1.0 11/12/2013