The lost era of pre-WIMP post-glass teletype software
Many years ago, when the world was young, and DOSosaurs roamed the earth, we wrote a piece of software for vehicle scheduling. It had a UI written in a library using GEM. In order to fit 50 rows of 80 characters on an EGA screen (640 by 350) a colleague had sat down with graph paper one weekend and designed a font which looked OK with characters 7 pixels high and 8 across (you can find some around now IIRC but his looked better than the ones I have found decades later). Then each character could have one of 8 foreground and background colours.
The software would schedule deliveries (main areas - breweries, oil tankers, deliveries to corner shops and the like) displaying each route in rows with 2 characters per drop - with the foreground and background colours of each character meaning something (e.g. order type, constraints, early or late delivery etc.)
The user could then use the keyboard to move orders round e.g. move delivery 3 from vehicle 7 to position 9 on vehicle 8 by something like M<enter>3<enter>7<enter>9<enter>. Some of the users could do this amazingly fast, I remember we had to find a TSR to increase the keyboard buffer from one of them - they were doing this at the speed of a fast typist. You couldn't get anywhere near this speed with a mouse, I don't think.