That looks like something similar to a Litton 72. I never got to use those, but I did (and still do) have the pleasure of using it's descendant...the Litton 92.
Unlike the modern FMSs, you have no ability to program in airways....each waypoint must be typed in individually. This gets interesting when flying over Europe, as Germany in particular feels the need to insert an intersection ever 10 miles on jet routes.
The improvement over the LTN 72 is that you can now program in up to 99 waypoints...I'm sure it was a marvel in it's day. The display itself compared to the LTN 72 also makes it look like an HD TV. Talking about displays....this unit has no ability to send images/interact with a moving map display. A CDI is all you have.
Our DC-10s have been upgraded, and we now rely on GPS nav, HT9100 FMSs and color moving map displays to get us to where we need to go. The LTN 92 is still there, but only as a lonely control head to the #3 INS unit on the center pedestal. It's a comforting backup to have, though.
(BTW, I've attached a picture of a LTN 92. It's the first time I've done this, and I have no idea how to control where it appears on this post....so my apologies if it's in some akward spot and/or too big)