FAQ

They are regular .ti59, .ti58, or .ti58c text files that can be anywhere on the file system. On Mac, the preset picker opens them from disk; on iPhone and iPad, use the built-in file picker.

Yes. The GitHub repository includes an 'examples' folder with a selection of .ti59, .ti58, and .ti58c files.

This feature is still a bit experimental. You can load these examples on the 'CPU' tab of the debugger. Use the buttons at the bottom to select a file, and run it.

Click away the error, click 'Freeze', then click 'Resume', and you should be on your way.

The virtual cards are stored in the app's iCloud storage. On iOS and iPadOS, use the card picker to load or save them. On Mac, they are also available in the file picker under the 'iCloud Drive/Calc-U-59' folder.

The TI-58C state file is stored in the app's iCloud storage (ti58c.mem). The file is written and loaded automatically when you switch to the TI-58C model.

Yes. Use the debug pane: CALCULATOR for program state and registers, CPU for the ROM instruction trace, and LOG for text output plus trace controls.

Open the debug pane, switch to LOG, and turn TRACE on. The app writes a binary session file to the configured trace location.

You first need to download the trace file to your computer. If you use the Mac emulator, this is already a given. When you generate the trace file with an iPad, then use 'Settings' to choose a good location. One option is to save the file directly to iCloud, and let the iPad sync it for you. Retrieve the file from iCloud on your PC. Download the 'read_trace.py' script from GitHub to convert the binary file to a readable format. The script is available in the 'tools' directory of the GitHub repository.

The CPU tab only traces while it is visible. When you switch to it, the heat map resets because any activity since you last left would be missing anyway. Exception: if the CPU is already frozen when you switch, the heat map is left intact — there is nothing new to miss.

In the CPU tab, F.START arms a scan-loop exit trigger: it freezes the moment the calculator leaves the keyboard idle loop — either because you pressed a key (the ROM exits the loop to handle the keystroke) or because the calculator was reset. This lets you catch the very first ROM opcode of a key-press handler without having to time a manual FREEZE. Only one F.START can be armed at a time; arming one tab silently disarms the other.

Switch to the CPU tab and press F.START (Freeze on Start). Then go to the calculator and press Reset — the CPU will freeze at the first ROM instruction of the reset routine. Use STEP to walk through it one opcode at a time.

This is expected. The ROM's key-debouncing logic registers a keypress only for a very short window. When F.START fires, the CPU freezes at the first instruction after the scan loop exits — but that window has already passed by the time you press RESUME or STEP. The key handler never sees the keypress and the calculator returns to idle. Use a TRACE capture instead: it records the full keystroke sequence without stopping the emulator, so the debounce window is never interrupted.

Yes. Copy or cut the output, and paste it into a text editor.

Add a CUECARD: section to a state file: set Template to MagnetCard or CueCard, then fill in fields A through E and A′ through E′ for the two key rows. Load that file (or write it onto a virtual magnetic card to keep the label with the card) and it appears on screen. See Loading a state file → Labeling the A–E and A′–E′ keys for the format, the math shortcuts, and the loading options.