Hardware/software trade‐offs for bitmap graphics on the blit

The Blit is an experimental bitmap graphics terminal built for research into interactive computer graphics on the UNIX time‐sharing system. The hardware is inexpensive and the graphics functions are implemented entirely in software. Nevertheless, the graphics performance of the Blit is comparable or superior to some displays with special‐purpose graphics hardware. This paper explains the paradox by referring to some principles of design: the hardware and software should be designed together to complement each other; carefully designed software can outperform infelicitous hardware; and simplicity of design leads to efficiency of execution. These principles are illustrated by examples from the Blit hardware and software and comparisons with other systems.