Calc-U-59 is a TI-59, TI-58, and TI-58C emulator for iPhone, iPad, and Mac. It runs the original ROM, so every program, module, and quirk works exactly as it did on the real hardware — with virtual magnetic cards, a PC-100C printer, all fourteen Solid State Software modules, and a CPU-level debugger for anyone who wants to look under the hood.
CYCLE-ACCURATE EMULATION
The TMC0501 processor is emulated at the cycle level, reproducing the exact behaviour of the original hardware — including the TI-58C's constant memory, preserved across restarts. The Master Library ROM and many more modules are included.
INTEGRATED DEBUGGER
Inspect program memory, data registers, CPU state, and internal SCOM registers live as the machine runs. Step through instructions one at a time, or let the emulator run and freeze it at any point. You can even run your own assembly programs! Available on iPad (landscape) and Mac.
PAPER TAPE PRINTER
A functional recreation of the PC-100C thermal printer with dot-matrix font rendering. Trace exactly what programs print and why. Copy output as plain text or as a high-resolution bitmap.
MAGNETIC CARD READER
Load and save programs and data registers as card files, stored on your device and synced via iCloud. Bring old listings back to life and run them under the debugger.
STATE FILES
Load .ti59 and .ti58(c) state files to instantly configure the machine with a program, registers, and flags — ideal for sharing reproducible scenarios or revisiting known machine states.
SOLID STATE MODULES
Select a Solid State Module and run programs from there.
Whether you're bringing an old program back to life, running the Master Library modules, or exploring how these machines actually worked under the hood, Calc-U-59 gives you a faithful TI-59 in your pocket.
Ratings & Reviews
5.0
out of 5
1 Ratings
• ERROR MESSAGES: File-load error alerts now show a title that matches what actually failed (state file, card, or ASM load/save) instead of always saying "ROM load error". A state file that isn't valid UTF-8 (e.g. saved with a curly quote or em dash in a non-UTF-8 encoding) now gets a specific explanation instead of a generic "Cannot read file."
• STATE FILES: New "PencilColor:" CUECARD keyword ("black" default, or "pencil"/"sharpie") lets a CueCard or MagnetCard's title/row/label text use an ink color that contrasts against the template's printed divider lines instead of blending into them. SolidStateCard is unaffected — it always renders in its fixed printed gold.
FIXES
• KEYBOARD: Fixed key presses on iOS/iPadOS being dropped intermittently (most presses not registering) under iOS 27's revised touch-gesture timing. Key tracking now reads touches directly instead of through the higher-level gesture API, restoring the same reliable, immediate response as before. macOS input is unaffected.
• STATE FILES: Fixed "\blank" CUECARD labels (used to merge grid cells into a spanning label) silently turning into empty labels after a save/reload round trip through "ti58c.mem" — the invisible marker is now written back out as literal "\blank" text instead of a raw zero-width space, which whitespace-trimming was stripping on reload.
Version 1.7.0
The developer, Martin Erzberger, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
