Basic logic probe design help

[mkv1091]

I have to construct the logic probe shown on the computer. Some of the connections are not shown though. After, i need to test it and make sure it works. D1, D2, D3, D4 are diodes. D5 and D6 are LEDs. 1 LED needs to be red, the other green (to show high/low). Im lost onto how to connect the switch/switches the right way. I believe thats the only thing that is missing? Here is the picture of the probe/schematic which is not showing all the connections.

https://imageshack.us/photo/my-images/210/logicprobe.jpg/

Any help would be greatly appreciated. Thanks.

 

[House0Fwax]

Quite simply. Where it says red, you put your power lead positive. Where it says black you put your negative lead. The only switching point I can see is between the 3.9K resistor and the 'already placed' black lead. Short it to the black lead to check for TTL. Leave it disconnected otherwise.

 

[colin55]

Here is a simpler circuit: