# Calc-U-59 — Calc-U-59 Calculator Emulation > Research tool for emulating and debugging classic TI-59, TI-58, and TI-58C calculators. (iPhone/iPad app by Martin Erzberger.) - Source: https://appshunter.io/ios/app/calc-u-59/id6761413142 (this page in markdown: same URL + `.md`) - Developer: [Martin Erzberger](https://appshunter.io/developer/1889469770) - Category: Productivity - Price: Free - Rating: 5.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 18.0 · 6 MB - Languages: American English - Released: 2026-05-05 - Data updated: 2026-08-19 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/calc-u-59/id6761413142/reviews.md ## What is Calc? 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. ## Key features - Cycle-accurate TMC0501 processor emulation - Integrated debugger for program and register inspection - Functional PC-100C paper tape printer recreation - Magnetic card reader for loading/saving programs - State file loading for instant machine configuration - Solid State Module support ## Frequently asked questions about Calc ### What classic calculators does Calc-U-59 emulate? Calc-U-59 emulates the TI-59, TI-58, and TI-58C calculators. It provides cycle-accurate emulation of the TMC0501 processor, including the TI-58C's constant memory feature. ### Can I debug programs with Calc-U-59? Yes, Calc-U-59 features an integrated debugger. You can inspect program memory, data registers, CPU state, and internal SCOM registers live, and step through instructions. ### Does Calc-U-59 have a printer simulation? Yes, Calc-U-59 includes a functional recreation of the PC-100C thermal printer. You can trace printed output and copy it as plain text or a high-resolution bitmap. ### How can I load and save programs in Calc-U-59? You can load and save programs and data registers using the magnetic card reader emulation, which stores them as card files on your device and syncs via iCloud. State files (.ti59, .ti58(c)) can also be loaded for instant machine configuration. ### What devices is Calc-U-59 available on? Calc-U-59 is available on iPad (in landscape mode) and Mac. It is rated for ages 4+. ### How often is Calc-U-59 updated? The latest version, 1.3.0, was last updated on June 20, 2026. The app was released on May 5, 2026, indicating a relatively frequent update schedule. ### Does Calc-U-59 have ads? No, Calc-U-59 does not contain advertisements. It is a free application focused on research and emulation. ### What is the user sentiment for Calc-U-59? Calc-U-59 has a perfect rating of 5.0 stars from 1 review, indicating very positive initial user sentiment. ## Version history (last 5 releases) ### 1.6.0 — 2026-08-13 • KEYBOARD: The Mac app now takes input from a physical keyboard: the number keys, the yellow operation keys ("Esc" for CLR, "Enter" for "=", "‹" for +/−), the A–E function keys via "a"–"e", and EE "(" ")" on "›" "(" ")". "Shift"+"A"…"E" gives A′–E′. Everything else — 2nd, STO, RCL, LRN, R/S and the rest — stays mouse-only by design. The full map is in "reference/AppArchitecture.md" § "Physical Keyboard Mapping". Typing works as soon as the app opens — the calculator does not have to be selected first. Clicking into the debug panel hands the keyboard over to it until you click back on the calculator. The printer and debug panels have no keyboard bindings of their own. iOS and iPadOS are unaffected. • APP ICON: Rebuilt as a layered Icon Composer ".icon" document, adding Liquid Glass depth and Light/Dark/Tinted/Clear appearance variants on iOS/macOS 26. • STATE FILES: New "Trace: name.bin" / "Trace: Off" keywords turn CPU instruction tracing on or off while a state file's KEYSTROKES are executing. • STATE FILES: New "FullSpeed:" / "RegularSpeed:" keywords toggle full speed persistently (no auto-revert, unlike "WaitFullSpeed:") while a state file's KEYSTROKES are executing. • STATE FILES: New "ZeroElapseTime:" / "ReportElapseTime:" keywords snapshot and report elapsed emulated time during KEYSTROKES playback, for measuring program run time. • DOCUMENTATION: Reworked the repository's documentation around a strict split: "reference/" and skill files are developer-only, the "www.calcu59.ch" website is the sole home for end-user content, and README now links to it once instead of duplicating it. Consolidated the ".ti59"/".ti58"/".ti58c" state-file and CUECARD format into a new "reference/StateFileFormat.md" (previously scattered across a skill file and a section of "DebugAPI.md"), folded "reference/USERGUIDE.md"'s still-relevant ASM Overlay content into "DebugAPI.md" and retired the rest as redundant with the website, and trimmed several skill files that were restating facts already in "reference/". FIXES • STATE FILES: Fixed "REGISTERS:" lines for register numbers 60–99 being loaded into the wrong RAM cell on the TI-59 (they were mistaken for the TI-58C's unrelated extra "H00"–"H03" registers, which happen to live at raw RAM indices 60–63). Ordinary TI-59 registers now always use the correct top-down "STO"/"RCL" mapping regardless of number; only true TI-58C extra registers use the raw mapping, now selected by an explicit flag instead of a numeric-range guess. • KEYBOARD: Fixed a held key's matrix bit staying stuck set in the emulator core if the keyboard/R\/S automation button view was torn down (e.g. rapid panel switching) mid-press, instead of releasing normally. • UI: Fixed toolbar, printer, and debug panel buttons shifting position on iOS when the Button Shapes accessibility setting is enabled. ### 1.5.0 — 2026-07-07 • PRINTER: Dot-matrix output now correctly supports printer-interrupt, also known as "High Rez Graphics". This is a hack documented in the 1982 magazine "PPX Exchange". Check the GitHub repository for the example state file "texas-print.ti59". FIXES • PRINTER: Multiple blank-line errors fixed (ADV button). Blank lines now match the real PC-100A/B/C exactly. • DEBUG LOG: Fixed out-of-memory crash and GUI slowdown when the LOG panel is active at DEBUG level. ### 1.4.0 — 2026-06-29 • STATE FILES: New "MODEL:" keyword switches the machine variant (TI-59/58/58C) when a state file is loaded. • STATE FILES: New "WaitFullSpeed: Xs" keyword runs the calculator at full speed for the given duration before continuing. • STATE FILES: New "SKIP-RESET:" directive applies only PROGRAM, REGISTERS, and KEYSTROKES to the running machine, skipping the reset. • STATE FILES: Printer tape is cleared whenever a state file is loaded. FIXES • ASM OVERLAY: Running an overlay no longer spuriously times out. • ASM OVERLAY: FREEZE ON START in the CPU tab now also triggers when Run is pressed in the ASM Overlay. • CPU DEBUGGER: KEY instruction disassembly no longer shows a spurious digit suffix. ### 1.3.0 — 2026-06-20 New - Calculator Debugger; Enables tracing and single-stepping of solid-state module keycode programs. - Portrait View: Enables the debugger in portrait view as well (disabled by default, enable in Settings). Particularly useful for iPhone users who previously had no debugger access. - ROM Heatmap: Hover over (or touch and hold) a block to see its hex address in the header. - CPU Debugger: Binary flag registers are now grouped into nibbles for readability. - Debugger: Hold the STEP button to step continuously at 4 steps per second. Fixes - Debugger: Moved the RESUME button to the left of FREEZE to avoid accidental presses while stepping. - CPU Debugger: Registers A–E and Sout are displayed MSN-first. - CPU Debugger: FREEZE ON START now triggers on a keypress or on reset of the calculator. This allows single-stepping the reset routine. - Trace: File size limit is now enforced by disabling TRACE when the limit is reached. ### 1.2.0 — 2026-06-11 - CPU Debugger: Live view shows the same information as "frozen"; New "ROM heatmap" is a visual indicator which parts of the ROM got executed so far. - Debuggers: Debuggers are always active (on/off sliders removed). - Samples: Additional samples. Fixes - Debugger: Clearer labels "Calculator", "CPU" and "Log" to indicate what the panels actually do. - Canvas: Cosmetic improvements on canvas, e.g. on key "9". - Core: Fix error in original ROM code obtained from Datamath - Cue Cards: Fix rendering of empty cue card labels - Debuggers: Fix buttons jumping around, fix state machine for the buttons. - Calculator Debugger: Fix Arrow location in PROGRAM STEPS view --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-19.*