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.
- Photo-realistic look-and-feel
- Three skins: version 1, versions 2 & 3 (1973) and final version 4 (1974)
- Vintage mode
- Enhanced memory mode
- Key-click and key-glow, both optional
- Swipe left across display to correct wrong number entries
- 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%
Tap the wrench symbol to access the settings screen:
- HP-35 Version: select production version 1 (with the red dot), versions 2 or 3 (identical apart from the front panel label), or version 4 (with key legends molded into keys)
- Invisible Buttons: If the Settings and Information buttons are distracting, you may hide them. They still work if you tap at the correct position. Alternatively, double-tap the display to open the Settings screen.
- Vintage Mode: see below
- Enhanced Memory: see below
- Key Glow Effect: tapping a key will shortly show a white glow around it
- Sound Volume: select desired volume of key click.
In this mode, RPN-35 SD simulates a real HP-35 very closely:
- Original speed of operation
- Stack register Z gets copied to T on trig functions
- Leading zeros may be entered
- 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
- Arithmetic precision is not simulated
In Vintage Mode, the settings button (wrench) is shown in blue.
Enhanced Memory Mode
In this mode, available only if Vintage Mode is off, RPN-35 SD provides advanced register handling.
- Non-volatile stack and registers
- Addressable registers R1...R9 supporting STO and RCL arithmetic like the HP-45
- Last X operation, performed by entering RCL 0
iPhone 6 Screenshots:
HP-35 Version 3
HP-35 Version 4