How to use Google Forms for data entry in a lab, keeping track of which computer input each entry?

Question

I wanted to use Google Forms for the following:

1. People come into the lab, seated at 1 computer desk each. They do not sign in with any personal info.

2. They enter addresses from a phone book (through Google Form) one at a time.

3. We (the managers) see a single spreadsheet with all the addresses entered, with a column telling us which address was entered by which computer.

Note I could ask them to enter their computer number each time, but unless the separate computer numbers come pre-filled, they may forget to do this for all entries … and anyways, it is time consuming.

Is there a solution?