Isonic is an application for designing and simulating computer architectures. It combines schematic capture with live logic simulation, letting you build circuits - from single gates up to full CPUs - out of wires and ICs and watch signals propagate in real time.
Beyond off-the-shelf parts, Isonic lets you emulate your own real ICs: define a chip's pinout and behavior once, and place it like any other component. Multi-layer routing with vias, a per-net diagnostics overlay (bus conflicts, floating pins, fan-out warnings), and a way to program an EEPROM's contents directly all make Isonic a schematic-design foundation for PCB development, pairing schematic entry with the groundwork for PCB layout and routing in one tool.
Manual download
- Go to github.com/ortanaV2/Isonic/releases
- Open the most recent release
- Under Assets, download
isonic-windows-x64-<version>.zip - Unzip it to any location
- Run
isonic.exe
- Live logic simulation — signals propagate across nets every frame; bus conflicts, overwritten drivers, floating pins, and fan-out overloads are flagged automatically by an on-canvas diagnostics overlay.
- Multi-layer routing — organize wiring across any number of named, colored layers (with GND/POWER roles), connected with vias where they need to cross.
- EEPROM programming — an AT28C64B's memory can be viewed and edited directly, byte by byte, through a "Manage Data" panel, without wiring up its address/data/control pins.
- Custom ICs — new chips are added by defining their pinout and behavior
once (see
src/ics/); they then show up in the parts menu like any built-in part. - Annotations — Section-Labeling draws a labeled, resizable, lockable rectangle to frame off part of a schematic; Text Label drops a single freestanding line of text — both purely organizational, with no effect on simulation.
Isonic targets Windows and requires a C11 compiler, SDL2, and SDL2_ttf
(sdl2-config must be on PATH) — MSYS2/mingw64 is the intended environment.
mingw32-make
Produces isonic.exe. make run builds and launches it, make clean removes
build artifacts.
Schematics save as .isonic files — a plain-text, versioned key=value
format that's safe to diff or read by hand. Settings (autosave interval,
Layers panel corner, keybinds) persist to %APPDATA%\Isonic\settings.ini,
independent of any schematic file.
- Left click — tool-dependent: place/draw with the active tool, or select/drag in Select mode
- Right click — delete whatever's under the cursor
- Middle mouse drag — pan the camera
- Mouse wheel — zoom (centered on the cursor)
- Mouse back/forward buttons — undo/redo
- W — switch to the Wire tool
- F — switch to the Via tool
- Space — switch to Select mode
- Q — switch to the Input tool
- E — switch to the Output tool
- T — switch to the Text Label tool
- R — while an IC is pending placement (Components menu, Ctrl+C, or Ctrl+V), rotate it 90° counterclockwise before dropping it
- 1-9 — pick which layer new wires route on
- Double middle-click — reset the camera to its default position/zoom
- Shift (hold) — preview all layers at once; Ctrl+Shift toggles that preview locked on/off
- Delete / Backspace — delete the current selection
- Escape — cancel the current action, close an open popup, or drop the selection
- Ctrl+S — save (falls through to Save As if the schematic has no path yet)
- Ctrl+Z / Ctrl+Y — undo / redo (Ctrl+Shift+Z also redoes)
All of the above (except the number keys, Delete/Backspace/Escape, and the Shift/Ctrl+Shift layer-preview chord) can be rebound from the Settings popup.
Tools are also selectable from the taskbar at the top of the window (Select, Wire, Via, Input, Output). The Components button opens a categorized, fold-up parts menu — click a category to expand it, then click a part to start placing it:
- Logic Gates — AND (SN74HC08N), OR (SN74HC32N), NOT (SN74HC540N), NAND (SN74HC00N), NOR (SN74HC02N), XOR (SN74HC86N)
- Multiplexers — 8:1 MUX (SN74HC151N), Dual 4:1 MUX (SN74HC153N)
- Demultiplexers — 1:8 DEMUX (CD74HCT238E), Dual 1:4 DEMUX (CD4555BE)
- Buffers — Tri-State Buffer (SN74HC244N)
- Latches — D-Latch (TC74HC373APF)
- Counters — 12-Bit Binary Counter (SN74HC4040N)
- Timers — Timer (TLC555)
- Memory — EEPROM (AT28C64B-15PU)
- Arithmetic — 4-Bit Adder (CD74HC283E)
- Obsolete — NOT (CD74HC04E, superseded by SN74HC540N above)
- File — New Schematic, New Window, Open File, Import Schematic, Save, Save As, Close Window (prompts to save unsaved changes first)
- Settings — autosave frequency, Layers panel corner, and keybind rebinding, with Save and Reset Default
- Section-Labeling / Text Label — a separate group to the right of Components, for framing and annotating a schematic rather than building it; see "Annotations" below
- Manage Data — appears when a single AT28C64B is selected; opens a panel to view/edit its memory contents directly
Section-Labeling drags out a light-gray rectangle to frame off part of a schematic, labeled at its top-right corner. In Select mode you can drag its body to move it, drag any of its 4 corners to resize it, or double-click its label to rename it — the small lock icon next to the label freezes all three against accidental changes (a locked section can still be selected and inspected, just not moved/resized/renamed, and stays out of Delete's way too). Typing the label happens immediately after you draw the rectangle; Enter or clicking elsewhere confirms it, Escape (or confirming empty) discards the whole section.
Text Label places a single line of freestanding text with a click, and starts you typing it immediately the same way. Double-click any placed label to retype it. Neither tool draws anything electrical — both are purely for keeping your bearings in a large schematic.
Docked below the taskbar (or centered on the left edge, if set in Settings): lists every layer with its color, name, and position in the stack. Click a row to make it the active layer for new wires, double-click a name to rename it, use the reorder arrows or delete button, or add a new layer from the row at the bottom.