http://alter.org.ua/en/soft/win/ntvdm_int28/

INT 28 idle implementation for NT VDM by Vitaliy Vorobyov aka DeathSoft […]
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INT 28 idle implementation for NT VDM
by Vitaliy Vorobyov aka DeathSoft

Situation: DOS applications use loop when waiting for user input.

Trouble: unnecessary power consumption, overheating and difficulties with background tasks (e.g. printing)

Solution: since DOS 2.0 new function was introduces for idle wait - INT 28. If the application uses this function, wait is performed with HLT instruction or some other task is executed.

Trouble N2: Virtual DOS machine under NT this function is not implemented. Thus event if the application uses INT 28, it consumes 100% CPU iven in idle state. That is why in multitask OSes CPU time is wasted with such programms. In addition new generation of processors emits significant amount of power nad gets very hot. This leads to much noise from coolers.

Solution N2: install the driver from the archive below.