RPN-35 SD [iPhone]

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.

Experience this unique calculator that won HP the prestigious "IEEE Milestone in Electrical Engineering and Computing" in 2009.

Features:

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

Vintage mode
In this mode, peculiarities of a real HP-35 are simulated:
- original speed of operation
- stack register Z 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
- for version 1 only: a number of known arithmetic bugs

Enhanced memory mode
- non-volatile stack and registers
- use registers 1 through 9 with HP-45-like register arithmetic
- register 0 works as LastX register