First you need to connect the black cable with the red and black alligator clip to a power source. 

For TTL chips that would be 5 Vdc and for CMOS that would be 3 to 15 Vdc. 

Red is plus and black is minus (ground). 

Next choose the proper cable and plug it in the top of the unit. 

If you choose the 40 pin clip on fior microprocessor and EPROMs you just have to clip it one. 
I think the clips should have a mark for pin #1 but if not you will just have to try it until

you get the right orientation. It won’t hurt anything if you put it on backwards. 

The others option to determine pin #1 on the clip would be to take a wire with +5 Vdc on it 

and touch the pin you think is #1 on the clip and see if the indicator shows #1 or #21 as that

are the only two options. 

For the second cable there are two 16-pin clips.The last 8 inputs have the input #’s tagged on

the wires with the individual test clips. One of the two gray test clips should be 

1 through 8 on one side of the display and 33 through 40 on the other. 

For the second clip the clip should have 9 through 9 through 16 on one side and 25 through 32 

on the other side. This is a little confusing at first but the best way to understand it would

be to take a wire connected to 5 Vdc and touch the contacts on each clip until you understand 

where they go on the display.