logic circuit simulator

version 1.2.1

    simcir is a simple simulator of logic circuits.

    click here to run

    system requirements

    java runtime environment java1.1. or higher


  1. choose a device from the toolbox and move to right side.
  2. connect them by drag+drop.
  3. click a input node to disconnect.
  4. move a device back to the toolbox if you don't use.
  5. double click the label to edit.


  • to simplify the model, all devices transfer only voltage but not current.
  • when logic gate's input node is not connected, it is treated as pulled down.