Logic gates, as real chips on a breadboard
Mokxi is a free logic gate simulator that runs in your browser, with nothing to install and no account needed. Most browser logic simulators draw an ideal symbol and stop there. Mokxi has ideal gates too, and it also has the 74HC00, 04, 08, 32, 74 and 86 as real DIP chips with supply pins, supply-relative thresholds and a propagation delay you could measure with a scope.
- 192parts on the bench
- 25boards running now
- 1.00xreal time, on every board
Ideal gates and real chips, on the same bench
One teaches the truth table. The other teaches the part.
The plain "Logic gate" and "Inverter" parts are ideal: two inputs, one output, no supply pins, a 10 nanosecond inertial delay so a pulse narrower than that never reaches the output at all. They are the right part for teaching the truth table before the chip.
The 74HC00, 74HC04, 74HC08, 74HC32, 74HC74 and 74HC86 are the real 14-pin DIP packages: four or six gates in one body, a VCC and a GND pin that actually have to be wired, and every output going high-impedance the moment the chip is unpowered. That last part is the single most common reason a beginner’s logic circuit does nothing at all, and Mokxi models it rather than hiding it.
What the running circuit above shows
Two buttons, a real NAND and a real XOR, four rows of a truth table you can press instead of read.
Two 10 kilohm pull-downs hold each input at 0 V while its button is not held, because a CMOS input left floating is not a zero, it is whatever charge happened to be on it last. Every gate on both chips carries the datasheet’s typical propagation delay of 9 nanoseconds from an input edge to the output moving.
The chips on the bench
Every logic part Mokxi has today.
Digital electronics, one circuit at a time
Explainers that each end in a circuit built from these chips, running.
Questions
Is it free?
Yes. Every gate and every 74HC chip, on the free plan, with no card.
What is the difference between the ideal gate and the 74HC chip?
The ideal gate has no supply pins and drives from nowhere, like a symbol in a textbook. The 74HC chip has to be powered, has a real propagation delay from the datasheet, and its outputs go high-impedance when it is not.
Can I build a flip-flop or a counter?
Yes. The 74HC74 is a dual D flip-flop with preset and clear, and the templates gallery has a binary counter built from two of them.
Do I need an account?
No. An account is only for saving a project to the cloud and sharing it by link.
Press Run on a real chip
Open the editor, drop a part on the breadboard and press Run. Nothing to install, and no account needed.