HP16C

Michael Doornbos · Utilities

4.2 4 ratings Free

Independent analytics for this App Store listing. AppTracker is not affiliated with Michael Doornbos.

Chart standing · US

Not currently charting in this storefront.

What changed · US

Listing changes AppTracker has observed for this app in this storefront — new versions, price moves, rating shifts, and store copy.

Oct 12, 2026
Rating ★ 4.33 → 4.25
Oct 2, 2026
Rating ★ 5 → 4.33
Sep 25, 2026
New version 1.0.6 → 1.0.7

Flag 3 works now. Set it with SF 3 and hex, octal, and binary values are padded with leading zeros out to the full word size, the way the original HP 16C shows them. CF 3 turns it back off. While fixing that, I found a bigger problem: SF, CF, and F? were taking the flag number from the X register instead of from the next key you pressed. On the real machine, the number is part of the keystroke sequence, so SF 3 is SF followed by 3. That's how it works here now, in programs as well. Thanks to the two people who wrote in about this.

Price & rating history · US

Reconstructed from the listing changes AppTracker has observed in this storefront. A field is charted once it has changed more than once, and each line starts at the value it moved from.

Average rating history over the observed period. 4.25 4.50 4.75 5.00 Oct 1 Oct 5 Oct 8 Oct 12 Oct 15

Average rating · ★ 4.25 now · 2 changes on record

Ratings breakdown · US

The star breakdown behind this app's rating in this storefront.

5★ 50% 2
4★ 25% 1
3★ 25% 1
2★ 0% 0
1★ 0% 0

Screenshots

About

A faithful recreation of the legendary HP 16C Computer Scientist calculator for iPhone, with a few modern upgrades. If you've ever needed to perform hex arithmetic, bit manipulation, or base conversion on your phone and been frustrated by the available options, this is for you. RPN-16C gives you the full power of the original HP 16C in your pocket. WHAT IT DOES - Full RPN (Reverse Polish Notation) calculator - Integer arithmetic in HEX, DEC, OCT, and BIN - Configurable word size from 1 to 64 bits - Unsigned, one's complement, and two's complement modes - Complete bit operations: shift, rotate, rotate through carry, AND, OR, XOR, NOT, mask, bit set/clear/test, count bits, left justify - Float mode with configurable precision (FLOAT 0-9) - Keystroke programming with labels, subroutines, loops, and conditionals - Storage registers with direct and indirect addressing - Programs can be imported from text (long-press the display to paste) ENHANCEMENTS OVER THE ORIGINAL - Two-line display: see both X and Y registers at once. No more guessing what's on the stack. - Wider LCD: displays all 32 bits in binary without scrolling. The original could only show 8 at a time. - Haptic feedback on every key press - State persistence: pick up right where you left off - SHOW function to peek at values in other bases FAIR WARNING This is a quirky calculator. It uses Reverse Polish Notation, has no equals key, and expects you to know what two's complement means. If you're looking for a simple calculator, this is not it. If you've ever wished you could do a bitwise rotate through carry on your phone, welcome home. DESIGNED FOR PROGRAMMERS The key layout matches the physical HP 16C exactly, including the f (gold) and g (blue) shift labels. If you know the original, you already know this one. The original HP 16C Owner's Handbook is freely available on the Internet Archive: https://archive.org/details/hp-16c_handbook

What's new · 1.0.7

Flag 3 works now. Set it with SF 3 and hex, octal, and binary values are padded with leading zeros out to the full word size, the way the original HP 16C shows them. CF 3 turns it back off. While fixing that, I found a bigger problem: SF, CF, and F? were taking the flag number from the X register instead of from the next key you pressed. On the real machine, the number is part of the keystroke sequence, so SF 3 is SF followed by 3. That's how it works here now, in programs as well. Thanks to the two people who wrote in about this.

Details

ReleasedApr 2026
UpdatedJun 2026
Version1.0.7
Size0.8 MB
RequiresiOS 17.0 or later
Age rating4+
LanguagesEnglish
PriceFree
Categories Utilities
Bundle IDcom.imapenguin.HP16C