PortSetModemStatusShadow

cCall [pPortSetModemStatusShadow], <hPort, dwEventMask
    <OFFSET32 MSRShadow>>
or      eax, eax
jz      error_handler

Sets the location of the modem status shadow for a port. The port driver updates the byte at this location whenever the modem status register changes. Uses the C calling convention.

• Returns TRUE if successful, FALSE otherwise.

hPort

Address of a _PORTINFORMATION structure returned by the PortOpen function.

dwEventMask

Specifies the new event mask for the port.

MSRShadow

Address of the modem status shadow.

When a port is opened, the modem status shadow is the bMSRShadow field of the _PORTDATA structure.

VCOMM calls this function when the VCOMM_PM_API_SetMSRShadow protected-mode API is called. This enables the 16-bit Windows communications driver to set the modem status shadow to a location in the system VM. There is no equivalent VCOMM service.

See also _PORTDATA, _PORTINFORMATION, PortOpen, VCOMM_PM_API_SetMSRShadow