PollStatusIterations

HKLM\SYSTEM\CurrentControlSet\Services\i8042prt\Parameters

Description

(This entry has limited use in Windows 2000. See Notes below.)

Specifies the maximum number of times the system verifies interrupts on the i8042 controller status register. If the interrupt cannot be verified in the number of trials specified in PollStatusIterations, the interrupt is ignored.

This entry is designed to minimize the effect of interrupts raised before the Output Buffer Full bit is set in the i8042 status register. This condition occurs on some computers, such as the Olivetti MIPS computer.

If the system seems to ignore keyboard interrupts, increase the value of this entry. The system might mistakenly ignore an interrupt if the Output Buffer Full bit is not set when the interrupt is raised. However, if you increase the value of PollStatusIterations, the Interrupt Service Routine will take longer to execute because there is a one-microsecond delay following each check for Output Buffer Full.

Note

This entry is used only when a device is installed. When the system recognizes a new device, it copies this entry to a device-specific subkey in the Enum subkey. Thereafter, it uses only the entries in Enum.

Tip

To determine whether the driver is processing keyboard interrupts correctly, press the NUM LOCK key. If the Num Lock light on the keyboard turns on or off, this indicates that the i8042prt driver handled the keyboard interrupt correctly.