Radar Overhead.
At Northern we had a feed from Staxton, albeit on another screen mounted on top, none of this poofy "composite picture" stuff they have nowadays.
This allowed half of the consoles to still see traffic in the Northern Overhead, as well as Midland and Eastern's.
At Border we had the luxury of three heads spinning away upstairs and a feed from Staxton as well as from somewhere else. The Border Overhead was less of an issue as we got so much less traffic than Northern, and mostly it was handled by a procedural crossing of the overhead, on a strict "non deviating" agreement.
Many evenings were spent watching the fighters playing out to the East while scrolling through the ARC52 trying to find the right Fighter Stud to follow the fight. It was difficult to keep coming up with excuses to go into see the Fighter Marshall, carrying a bit of paper to write down freqs that we shouldn't have been looking at, never mind taking out of the room on paper.