Calc-U-59
Calc-U-59 Calculator Emulation
About
Explore the inner workings of classic TI-59, TI-58, and TI-58C calculators. This tool offers cycle-accurate emulation, a debugger to inspect code and registers, and a functional paper tape printer recreation. Load and save programs using magnetic card emulation and state files.
What's New in Calc
1.6.0
August 13, 2026
• 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.
MoreFAQ
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.