7.1.2 Installing Serial Drivers

This provides information on how to install a serial driver (or serial driver emulator) so Remote Access setup can be configured to use that driver.

Write a configuration utility that installs the driver. Package the configuration utility as a DLL that can be started from the network control panel by using an installation script (.inf file). Users can then install the hardware by using the network control panel application, clicking the “Add Adapter” button, and installing the correct driver.

Port Naming

Serial Adapters (serial driver emulators): COM1, COM2, ... COMm

Windows NT Registry

For an X.25 adapter with a serial driver emulator, merge the [X.25_card_name] script section in with the Remote Access pad.inf script located in the RAS subdirectory of the Windows NT system directory, for example, winnt35\system32\ras. The Remote Access Service Administrator's Guide provides details on how to write a pad.inf script.

Indicate which COM ports the driver exposes to the system by storing information in the Windows NT registry's hardware devicemap as shown in the following example:

HKEY_LOCAL_MACHINE
    HARDWARE
        DEVICEMAP
            SERIALCOMM
                Serial0    REG_SZ  COM1
                Serial1    REG_SZ  COM2
                    .
                    .
                    .
                Serialn    REG_SZ  COMn
 

If there are one or more serial ports in the local system, the SERIALCOMM key will already exist. The serial driver installation script should then add the number of supported serial ports to the existing list of ports. When a serial driver is loaded, it must add the supported ports to the SERIALCOMM key because this information is updated every time the system is restarted.