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Single screen display system with multiple virtual display having prioritized service programs and dedicated memory stacks

  • US 4,484,302 A
  • Filed: 11/20/1980
  • Issued: 11/20/1984
  • Est. Priority Date: 11/20/1980
  • Status: Expired due to Term
First Claim
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1. Apparatus for generating multiple virtual displays on a single display screen, comprising:

  • a single processor for controlling the operation of said apparatus,a partitioned memory having a plurality of dedicated areas corresponding to a number of multiple virtual displays on the single display screen, each of said dedicated areas including a service program area, a stack element area, a buffer area and a display control block area,a display access method program stored in said memory for running a plurality of service programs stored in said service program areas, each of said service programs having an interrupt priority and associated with a separate virtual display on said single display screen, andan interrupt arbitrator responsive to an interrupt calling a high priority service program for interrupting the processing by the processor of information on the virtual display associated with a low priority service program, said interrupt initiating the processing by said processor of information on the virtual display associated with said high priority service program.

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