Brilliant episode.
There was also an NEC version of these about, and I'm not sure who was really first, Tandy or NEC....
We used the NEC versions as the standard terminal interface into our weather radars to configure and calibrate the systems.
People found the Tandy model also worked, but the cursor keys were not so friendly.
If you approached one of our older radars, it would still function OK into one of these machines when switched into TELCOM mode.
Good ol Telcom - Real weird arse serial protocol, the closest match turned out to be the Heath 19 terminal format, of Heathkit fame.
It was definitely not VT100 or other more popular forms, and I think ANSI was still an itch in someone's pants back then.
Perhaps it was one of those "Microsoft standards" that never caught on!
I spent far too many years building menus that would work on that 40x8 display, and the cursor keys that the NEC was quite prominent with them in a diamond pattern, were used extensively.
I eventually wrote a PC application to emulate the terminal protocol used by these devices as the only thing that worked on the PC was Procomm in Heath-19 mode, and the NEC devices/Tandy devices were already unobtainium.
9600N81, it still brings a tear to the eye :-)
BTW, gotta love those sexy curved PCB traces, that's when a PCB design was a beautiful work of art/craftsmanship/design before PC software enforced those rigid angular corners.