ANSI art
Colourful text-mode graphics built from the IBM PC's block characters and ANSI colour codes — the login screens and menus of the BBS world.
ANSI art is drawn with the code page 437 character set — full and half blocks, shade patterns, lines — and coloured with ANSI escape sequences the terminal interpreted on the fly. Sixteen colours, sometimes blink, no resolution finer than the character grid. On the BBSes of the 1980s and 90s it was the standard for login screens, menus and group signatures.
Whole art groups formed around the craft — ACiD and iCE the best known — releasing monthly "artpacks" of hundreds of images. ANSI was the colour cousin of the plainer ASCII art; once the web took over the BBS's role, the form became a nostalgic craft rather than a working tool.