10 PRINT CHR$(205.5+RND(1);: GOTO 10 

Piece of code in the Commodore 64 manual, used in a small digital art show called ‘Codings’ at the Pace Digital Gallery, New York, which looks at code, text and digital art:

A 3-line version of this program appeared in the original Commodore 64 User’s guide:

10 PRINT “{CLR/HOME}
20 PRINT CHR$(205.5+RND(1)
30 GOTO 20

This is one of many short basic programs, for this and other computers, that have been entered by users seeking to puzzle their friends, to learn more about computing, and to see aesthetically pleasing output.

You can find out more about the show here

[sad confession - I never knew there was an easy bit of code to do this on a Commodore … I discovered the effect myself, but did it manually, typing the two characters myself at random …]

via prostheticknowledge