PollStatusIterations Entry

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

HKLM\SYSTEM\CurrentControlSet\Services\i8042prt\Parameters

Description

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 the value of this entry, then 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, then 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 this entry, then the Interrupt Service Routine will take longer to execute, because there is a one-microsecond delay following each check of the Output Buffer Full bit.

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 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.