RPN-35 SD is a photo-realistic simulation of Hewlett-Packard's break-through scientific hand-held calculator.

On January 4, 1972, Hewlett-Packard announced the HP-35, world's first scientific calculator small enough to fit in a pocket - more precisely, Bill Hewlett's shirt-pocket. The HP-35 was an immediate hit with students, engineers, and scientists. Despite its steep price of $395 (more than $2,200 today), it sold ten times better than anticipated in the first year. It was discontinued in 1975.


Features

• Photo-realistic look-and-feel


• Three skins: version 1, versions 2 & 3 (1973) and final version 4 (1974)


• Two Calculator Modes: Vintage and Enhanced


• Key haptics and key glow, both optional


• Swipe left across display to correct wrong number input


• Cut/copy/paste display value


• Display stack registers and all memory registers (tap display once)


• All decimal points but one light up when battery charge drops below 5%

• HP-35 Version: select production version 1 ("Red Dot"), versions 2 or 3 (identical apart from the front panel label), or version 4 (with labeled function keys)


• Calculator Mode: see below


• Registers: see below


• Haptics: select the desired level of haptic feedback when hitting a key. 0 = off.


• Key Glow Effect: tapping a key will shortly show a white glow around it


• Hide Extra Buttons: If the Settings and Information buttons are distracting, you may hide them (on devices not displaying the HP front label).
  They still work if you tap at the correct position. Alternatively, double-tap the display to open the Settings screen.


• Sound Volume: select desired key click volume.

• Original speed of operation


• Stack register Z gets copied to T on trig functions


• Leading zeros may be entered


• The sign of zero may be negative


• A negative number may be entered by pressing CHS before or after the number


• A keyboard entry or RCL immediately following STO does not raise the stack


• If HP-35 version 1 is selected, known arithmetic errors are simulated

In Vintage Mode, the settings button (wrench) is colored blue.

• High-speed operation


• Non-volatile stack and registers


• Higher precision of constants π and e


• Addressable registers R1...R9 supporting STO and RCL arithmetic like the HP-45


• Last X operation, performed by entering RCL 0


• Storing 1939010x in R0 sets the haptics level to x (0 = off)

HP35 Back Label

• New:
• • Redesigned Settings screen
• • Visual adjustments to iPhone 16 Pro and Pro Max
• • Requires iOS 12 or later

• New:
• • Haptics
    Set the haptic feedback level in the calculator's settings.
    Make sure that on your iPhone in "Settings / Sounds & Haptics" the option "System Haptics" is enabled.
    Note that iPads have no haptics engine.


• • Optimized Settings screen for devices not displaying the HP front label.

• New:
• • Compatiblity with iPhone 12

• Bug fix:
• • Calculations in scientific mode in regions not using "E" as exponent symbol (i.e. Sweden, Australia, Slovenia) would cause a crash.

• New:
• • If RPN-35 is set to HP-35 version v1 ("Red dot") and Vintage Mode is on:
    1. Simulation of (rather weird) EEX key behavior, i.e. exponent not shown initially, CHS ignored after digit entry, no CHS toggling
    2. Simulation of additional known calculation bugs.
• • HP-35 version 4 shows correct logo and label at the bottom (on applicable iOS devices.)
• • Support for iOS 13 Dark Mode
• • RPN-35 SD now requires iOS 11 or later.

• New:
• • Simulation of early HP-35 calculation errors

• New:
• • Changed "Undo digit" sound to same as found on other CuVee calculators
• • Internal optimisations
• • Support of late 2018 iPhones

• New:
• • Values containing blanks may be pasted into display

• New:
• • Improved compatibility with iPhone X

• Bug Fix:
• • Incorrect app icon shown when installed on iPad

• New:
• • Improved trig functions for extremely small angles
• • Support for iOS 11 and iPhone x

• New:
• • Improved results for SIN, COS, TAN with very large arguments
• • Decimal addition/subtraction for higher precision
• • Calculator sounds mix with background audio and have their own volume control

• New:
• • If audio is playing on start-up, RPN-35 SD will not produce any sounds

• If RPN-35 is set to HP-35 version v1 ("Red dot") and Vintage Mode is on: 1. Simulation of (rather weird) EEX key behavior, i.e. exponent not shown initially, CHS ignored after digit entry, no CHS toggling 2. Simulation of additional known calculation bugs. See website for details. • HP-35 version 4 shows correct logo and label at the bottom (on applicable iOS devices.) Version 3 shows the same label as version 2. • Support for iOS 13 Dark Mode RPN-35 SD now requires iOS 11 or later.
• New:
• • Added info about how to access settings screen
• • Fixed non-volatile memory not working

• New:
• • HP-35 version 1 (with red dot)
• • Settings and Info buttons may be set to invisible
• • Low-battery situation shows one decimal point unlit, as depicted in the HP-35 User's Manual

• First public version.

RPN-35 SD

Suomi