1. A system suitable for electronically storing, revising, and displaying technical drawings comprising: mass storage means for storing multiple data sets, each data set comprising digital data defining a pixel representation of a different technical drawing; operator input means for enabling an operator to selectively identify a data set stored in said mass storage means; monitor means for displaying a drawing; and control means responsive to said operator input means for controlling said monitor means to display at least a portion of the drawing identified by said input means, said control means including: pixel memory means for storing a bit map of a drawing; processor means for retrieving each data set identified by said operator input means and responsive to the digital data therein for loading a bit map into said pixel memory means; means responsive to said bit map stored in said pixel memory means for causing said monitor to display pixels representing the identified drawing; said operator input means including means enabling an operator to define a DRAWING REVISION MODE and to initiate the generation of primitives, each primitive defining an elementary display instruction and related parameter data; said processor means including means reponsive to each of said generated primitives for revising said bit map stored in said pixel memory means; and cache means for temporarily storing each of said generated primitives.