I recall some radars used those large round screens, long persistence phosphors. Often these were mechanically rotated in time with the antenna, with slide contact rings. Later electronic rotation superseded that.
All of this required complex electromechanical devices to generate (and eventually filter) the required signals.
As technology progressed and textual information started to be added to the process it became necessary to convert the polar plot to a conventional rasterized signal. This was accomplished with a scan converter tube which was essentially a polar CRT coupled to a TV camera. Radar would plot on the CRT and the camera would turn it into scanlines to be overlaid with data. This was used into the 90s and there's probably still operational systems relying on this.
They had these systems and a camera pointed right at one to rasterize them.
At the time, a whole lot was still analog. Beautiful systems.
Saw one of those 9 track tape drives too. On a seek, tape would just dissappear from one reel and accumulate on the other one --fast!
And then CLACK! It would stop and just start reading at what looked like normal speed. Was kind of impressive in its own way too.
Interestingly while the new system is much nicer to work with, much better resolution and features I didn't think were possible. The old system had power, and lots of it, and sometimes power is what you need.
The one I used had a joystick built right into the keyboard, and it ran a CNC programming environment.
Data I/O was paper tape via serial and data cassette. Ours did not have the floppy or fast refresh graphics options.
2048x2048 vector space! The big CRT could resolve most of that when well tuned.
The work process was:
Load editor from tape cartridge
Type it in, or read text from paper tape.
I had punched a fair number of shortcut G-codes and I would use them to get the bones of a new program started.
Write finished program text (g-code) to paper tape. That could and should include comments. (We put a setup sheet on the master tape, for example) This was a master.
Make another stripped down one, and this is production.
Prep a tape for reading by sticking the beginning of program end into the reader and put the reader into handshake mode.
Read it back to validate against program in RAM.
Or...
Load backplotter/ simulator. Prep program tape for reading.
Run the simulator, plotter. If it was a master tape, it would know the tooling setup and just draw all the operations to the CRT. And because it was a storage tube, those all would display and one could see what metal gets cut out easy enough.
This worked fairly well!
Once it was done, the production tape went into a can and was moved to a library. That was a whole wall of cabinets filled with little plastic canisters containing paper tape programs for everything.
1Mhz 6500 CPU.
And like I said, the Tek terminals were just fun to use.
It mostly just works.