## Virtual Device Driver Reference for OS/2

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### Idle Detection Support

DOS applications waste CPU time in a multitasking system when they peek for input in a loop. Idle conditions are detected when:

The application is polling the keyboard using INT 16h in a loop
DOS is polling in an input loop
Repeated INT 28h calls are received from a DOS application
INT 2Fh, AX=1680h yield calls are received
DOS INT 21h, service 0Bh calls are received

Two services are available to device drivers to assist and for handling, VDHReportPeek and VDHWakeIdle.