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Installing a Device Driver

There are ways to install a device driver, depending on where the driver code is stored and how much control you want over the installation process.

You can store the device driver in an expansion ROM, as described in Startup and System Configuration
You can store the device driver on disk in a file of type 'ndrv' in the Extensions folder.
Use the DLL

The first option, storing the driver in the card's expansion ROM, is the normal practice because it gives the card autoconfiguration capabilities, as described in Startup and System Configuration

See Finding, Initializing, and Replacing Drivers for driver loading and installation details. Driver Loader Library provides details of the mechanisms available for installing and removing drivers that are listed in the Device Manager unit table.

Table 8-2 lists the driver unit numbers that are reserved for specific purposes.

Table 8-2 Reserved unit numbers

Unit number range	Reference number range	Purpose
0 through 11	-1 through -12	Reserved for serial, disk, AppleTalk, printer, and other drivers
12 through 31	-13 through -32	Available for desk accessories
32 through 38	-33 through -39	Available for old SCSI devices
39 through 47	-40 through -48	Reserved
48 through 127	-49 through -128	Available for PCI and other drivers