Java Circuit Simulation Workaround ▾

Due to recent changes by Oracle, java applets have become difficult to run in the browser. To mitigate the troubles, Oracle has provided the following websites to help users troubleshoot: and

Even after following the above instructions, loading applets may still show warning concerning “unsigned application” and “unknown publisher”. For Teahlab in particular, these warnings are due to the fact that we have opted not to pay a third party such as Verisign to sign our applets. Any warning that comes up when you try to run our applets should emphasize that our applets will always run with “limited access”, which is Oracle’s way of letting you know that teahlab doesn’t do anything on your computer except running the circuits you see: in other words, our applets are safe to run.


The Teahlab Team

[ 4 TO 1 MUX ]

The 4 to 1 Multiplexer is a logic circuit whose function is to select one data line from among 4. For this reason, many people refer to it and all multiplexers as data selectors.


BUILD! SAVE! SHARE! any elaborate circuits completely online. NO DOWNLOAdING IS NEEDED! And have access to your circuits 24/7.


This Johnson counter counts from 1 to 8. Johnson counters obey two mathematical relationships: 2 * flipflops = count; ANDs = count.


This type of Finite State Machine is a digital circuit that can add any two arbitrarily large numbers using a single full adder.


Given any two 4-bit signed numbers X and Y, the circuit is able to differentiate the following relations: whether X = Y, X > Y, or X < Y.


The hierarchy of flipflops: from RS fliplop to D flipflop to JK flipflop to Toggle flipflop.