for a lot of 80s computers the command line / basic environment was an interactive thing. It would immediately execute your commands. Some of those commands w

for a lot of 80s computers the command line / basic environment was an interactive thing. It would immediately execute your commands. Some of those commands were for listing contents on disks and loading programs from disk/tapes. The simplest way to add the ability to build up a basic program on a command line is by a simple line editor where you get the classic '10 PRINT "Hello World"' which would immediately store away that line of code. Towards the end of my 8 bit days there were screen editors for things like doing 6502 assembly, and there was this cool language called "Action!" https://en.wikipedia.org/wiki/Action!_(programming_language) https://en.wikipedia.org/wiki/Action!_(programming_language) which also had a screen editor.