Pretty sure it was the way hi-res graphics worked on the VIC-20 too -- 22 characters by 8 pixels per character = 176 pixels wide, multi-colour mode where each block of 8x8 pixels had a background and a foreground colour. Deeply freaky.
a
b
and when you typed "b", it would emit: c
d
When I was about 8, I fooled with this peeking and poking pixels so that "a" and "b" bitmaps where the top and bottom halves of a double-height "a", through to the end of the alphabet. I imagined that this would make it easy for my grandparents to use computers. Never mind that they couldn't type, had no interest, and would never remember commands like "load $,8,1".edit: formatting