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This section describes functions in the VSL that help video drivers signal the Macintosh software to service display interrupts associated with the display attached to the frame buffer.
A driver can create as many interrupt services as it supports. The model described here supports different types of video interrupts, such as horizontal blanking and frame interrupts. It opens the door for specialized interrupts for specific applications (such as broadcast). For each queue it supports, the driver is responsible for calling VSLDoInterruptService when the associated interrupt happens.