The early
TRS-80s had a system of
character graphics for displaying rather
chunky-looking graphics on the screen. These characters split the possible
character display area up into a 2x3 grid (don't know the pixel
size of
a
character, but this suggests it was something like 6x9) and all the
combinations were available.
Some of these systems accomplished this by using a mutant 7-bit form of ASCII
with only 64 of the normal characters and 64 of these special graphic
characters; they didn't have lower case letters. (Later systems had a full 8-bit ASCII including lower case characters and these same graphics, starting with the Model III. High-resolution graphics was a separate capability that came later.)
The first systems had a display of 64x16 characters, for a full screen
graphics resolution (with these 2x3 symbols) of 128x48. Later ones had
an 80x24 display, which allowed a graphics resolution of 160x72.
This was the system I played Pillbox on.
All monochrome of course.
Tandy computers didn't get color until the CoCo years later.