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Files, Autosave & Undo

Chip Hippo separates two things most apps blur together: the circuit you're currently poking at, which is saved for you continuously, and a named schematic file you deliberately save to organize or share a specific design. This page covers both, plus the discard-changes prompt, the title bar's dirty indicator, and undo/redo.

The autosaved working document

Whatever is on the desk right now — every board, chip, wire, and part — lives in a working document that Chip Hippo saves automatically as you go. There's nothing to save manually for day-to-day tinkering: place a chip, lay a wire, quit the app, relaunch, and the desk comes back exactly as you left it. This is the same document that opens by default every time you launch Chip Hippo.

Named files

A named file (extension .chiphippo) is a snapshot of a schematic you've explicitly saved somewhere on disk — useful for organizing a design under a project name, keeping several circuits side by side, or sharing one with someone else. Once you've opened or saved a named file, it becomes the working document: further edits keep autosaving into it, and the title bar shows its filename.

New, Open, Save, Save As

Four commands on the File menu cover the whole file lifecycle:

The same four actions are also available as buttons in the header toolbar's schematic menu, alongside their keyboard shortcuts.

New and Open replace the whole desk, so the window refreshes to load it — a brief flash as everything rebuilds from the new document. Note that this resets any run-volatile simulation state (see below); it doesn't affect what's saved.

Unsaved changes

The title bar shows the current file's name (or "Untitled" for a fresh document) with a leading dot — • MyCircuit — Chip Hippo — whenever the desk has changes that haven't been written to that file yet. Save clears the dot.

Because New Schematic and Open Schematic… both replace the working document outright, Chip Hippo won't silently throw away unsaved work: if the desk is dirty, it shows a Discard unsaved changes? prompt naming the current file and asking you to confirm before proceeding. Choose Discard to continue (losing those changes) or Cancel to back out and save first.

Undo & redo

Cmd/Ctrl+Z undoes the last edit; Shift+Cmd/Ctrl+Z redoes it. Undo/redo covers the full editing history of the circuit — placing and moving boards, chips, and discretes; wiring and unwiring; deleting anything; net names — as far back as your session's history allows, and both menu items disable themselves automatically when there's nothing left to undo or redo.

Undo/redo does not cover simulation state. While the circuit is running, editing — and with it, recording new undo steps — is locked, so nothing that happens mid-run (sequential chip state, clock phase, a chip taking 12 V damage) ever becomes an undo step of its own. Sequential state and clock phase vanish outright the next time you press Run. 12 V damage is the one exception that outlives the run: it's written into the document, so stopping — or even quitting and reopening — doesn't clear it, and there's no Cmd+Z back to before it happened. The only way to clear a damaged chip is the right-click Replace chip action (see Power & Clock Sources) — which, taken while stopped, is a normal edit and undoes/redoes like any other. What undo/redo restores is always the circuit you built, never a moment in its simulated behavior.

Example circuits

Chip Hippo's project repository ships a handful of ready-to-load example circuits as ordinary .chiphippo files — currently small W65C02-based breadboard computers built from 74xx glue logic, each paired with a .hex ROM image. Open one the same way as any saved file: File ▸ Open Schematic…, then load its matching .hex into the ROM chip via the memory inspector or the external programmer before pressing Run.

See Getting Started for building your first circuit from scratch, and Settings for what else persists between sessions.