Hello I want to build a liitile project . Using my computer I want to make him signal generator and using the mic output pin of my computer to connect this pin to audio output computer . and on the second computer to build scope that will show me the signal from the first computer .
here is drawing of what i mean

 

You have it reversed.
Computer 1 (signal generator) outputs its signal via the headphones output jack.
Computer 2 (oscilloscope) gets the input signal from the mic or line input jack.

 

Computer1 generator should be green headphone/speaker out. Computer2 scope should be blue line in. These color codes can depend on type of computer.

You can use one computer without a cable for both apps....by using your sound mixer.

 

ok and is it posbiille ?

 

It will depend on your apps and your computer. Look at settings and help files on apps.

 

my question is simple . looking at the voltages can i connect 3.5 mm cable to one laptop to onther ?