TkGate is a digital circuit editor and simulator with a Tcl/Tk based interface. TkGate includes a large number of built-in devices including basic gates, memories, ttys and modules for hierarchical design. The simulator can be controlled either interactively or through a simulation script. Memory contents can be loaded from files, and a microcode/macrocode compiler (gmac) is included to create tkgate memory files from a high-level description. The simulator supports continous simulation, single step simulation (by clock or epoch) and breakpoints. Save files are in a Verilog-like format. TkGate also includes a number of tutorial and example circuits which can be loaded through the "Help" menu. The examples range from a simple gate-level 3-bit adder to a 16-bit CPU programmed to play the "Animals" game. For more information on TkGate, see the TkGate web site at: WWW: http://www.cs.cmu.edu/~hansen/tkgate/ Program and FreeBSD port by: Jeffery Hansen http://www.cs.cmu.edu/~hansen