Device for protecting selected information in multi-media workstations

摘要

The display buffer of a multimedia workstation is partitioned into a display section and a non-display section. The information to be displayed on the display screen is arranged in the display section of the display buffer. An image or shadow of the display section is written in the non-display section (called a lock buffer) of the display buffer. Prior to updating the display section, a controller reads the protection data from the lock buffer and generates control signals which inhibit the writing of data into protected areas of the display section.