This is how I started out my career back in the dayz ;)
Painting images on the C64 with a Joystick!
The graphics chip, VIC-II, featured only a resolution of 160×200 in standard color mode and only 16 colors (of which only 4 where usable in a 4×8 pixel cell) but soon those limits where broken with clever assembler code and exploiting serveral bugs of the chip.
You can find a pretty good overview of all the different image formats ‘invented’ over at Studio Style .
When there’s time I’ll add more of my old pixels … or new ones (X’2014 is approaching ;)