[tom_]

Depends on the system. Each thing did its own thing at the time.

8-bit Acorn systems did work kind of roughly as you describe. Handwaving a bit: there was no shell, but there was an OS call roughly corresponding to system(3), and add-on ROMs (e.g., the driver-type ROM that came with the disk interface) could extend the default (fairly limited) set of available commands.

With no shell, there was no standard UI for typing in a command and having it run, but this OS call was one of the main ways to interact with the OS, so the inbuilt BASIC made it very easy to do. For a lot of the stuff you'd use the DOS prompt for in MS-DOS, you'd do the equivalent from the BASIC prompt on the Acorn systems. In place of batch files, there were a couple of options, and one of them was that you'd write a BASIC program that contained the commands you wanted executed, in order.