Logisim Revisited
Logisim Revisited is a free, open-source digital logic circuit simulator, Karnaugh map analyzer, and interactive trainer built in TypeScript for the web and mobile devices. Inspired by Carl Burch’s classic Logisim 2.7.1, it runs 100% client-side in your browser with no Java Runtime Environment required.
Highlights
- 4-State Multi-Bit Logic Simulator (
@logisim/core): Simulates 0 (Low), 1 (High), Z (Floating / High-Impedance), and E (Error / Short-Circuit Conflict) across 1-bit wires and multi-bit buses (up to 32 bits).
- Classic Logisim Component Libraries:
- Wiring: Input Pin, Output Pin, Probe, Tunnel, Splitter, Clock, Constant, Power, Ground.
- Gates: NOT, Buffer, Controlled Buffer (Tri-State), AND, OR, NAND, NOR, XOR, XNOR, Odd/Even Parity.
- Plexers: Multiplexer, Demultiplexer, Decoder, Priority Encoder.
- Arithmetic: Full Adder, Subtractor, Multiplier, Comparator, Shifter, Negator.
- Memory: D, T, J-K, and S-R Flip-Flops, Register, Counter, RAM, and ROM.
- Input/Output: Push Button, LED, 7-Segment Display, Hex Digit Display.
- Symbolic AI Circuit Coach & Signal Prover:
- “Why is this wire/pin 0 / 1 / E / Z?”: Click any pin, gate, or wire net to trace signal propagation backward step-by-step from outputs to driving inputs, or pinpoint the exact competing drivers causing a red short-circuit (
E).
- 4-Stage Socratic AI Coach (
Coach me): Walks through circuit debugging, truth-table verification, and Karnaugh map prime-implicant grouping in four progressive nudges (Where to look, The pattern, The logic, Conclusion).
- Combinational Analysis (Truth Table ↔ Boolean Expression ↔ K-Map ↔ Circuit):
- Interactive 2-, 3-, and 4-variable Gray-code Karnaugh Maps with Quine-McCluskey minimal Sum-of-Products (SOP) and Product-of-Sums (POS) prime-implicant loops, plus one-click automatic schematic synthesis.
- Logisim 2.7.1
.circ XML Import & Export: Load and save standard Logisim .circ XML circuit files directly in the browser.
- Daily Logic Challenges: Date-seeded digital logic design and troubleshooting puzzles with shareable completion cards.
Quick Start
pnpm install
pnpm typecheck
pnpm test
pnpm --filter @logisim/app build
pnpm --filter @logisim/website build
pnpm --filter @logisim/website test
License
Free software under the GNU General Public License v3.0 or later (GPL-3.0-or-later). See LICENSE and docs/LICENSE-AUDIT.md.