[kens]

A historical note: even though the line/box-drawing characters go back to the IBM PC, they aren't ASCII. The PC used Code page 437, which added a bunch of characters to ASCII. To be genuinely ASCII, you need to draw your boxes with pipes and hyphens (| and -).

[afandian]

If you want a _real_ graphics mode in the spare bits of ASCII, check out MODE 7 (teletex) of the BBC Micro, page 488.

https://www.bbcmicrobot.com/docs/BBC_User_Guide.pdf