OS/8 was a single user OS (like RT11), so it often was used as a personal computer. It inspired CP/M.

6-bit chars were popular on this machine since you could fit two in one word, and uppercase only a thing. Strings in BASIC used 6-bit chars, but you could PRINT all ASCII (especially control characters) with a special PNT() function (only usable as a PRINT argument). If you look at the available OS/8 images, you'll find "business BASIC"- at least one change compared to regular OS/8 basic was support for 8-bit strings.

Floppies used 8-bit bytes. You wasted 4-bits out of every two for image files.