Method to Provide Concurrent Update of Multiple Physical Displays by Multiple Virtual Terminals
Original Publication Date: 1987-Jun-01
Included in the Prior Art Database: 2005-Feb-01
Some Display Management Subsystems allow multiple virtual terminals to be created. Each virtual terminal uses one and only one physical display at a time; however, many virtual terminals may share the same physical display. Fig. 1 illustrates the case where "N" virtual terminals share one real display. To avoid update conflicts, the concept of "ACTIVE" virtual terminal was introduced. Only the "active" virtual terminal has the right to update the real display. All other virtual terminals must update their internal representation (Presentation Space) of the information that would have been displayed had they been the "ACTIVE" virtual terminal. This new method gives "non-active" virtual terminals the ability to update their associated real displays concurrent with the "active" virtual terminal. As shown in Fig.