Windows 95/98

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Windows 9X Devices

Windows System Drivers

A driver is a software translator. It accepts the various commands from the operating system and translates them into specific commands for a specific piece of hardware.

Using drivers allow programs be independent of hardware. Hardware may be changed without affecting the program.

Why Use Drivers?

Drivers connect Windows with the hardware and provide device independence. When new hardware is created, a new driver can also be created; Windows itself does not need to change. Some types of drivers used by Windows are:

  • System
  • Sound
  • Keyboard
  • Communications
  • Mouse
  • Printer
  • Display
  • Network adapter

Supported Driver Types

To remain compatible with existing programs, Windows 95 supports the use of the following drivers.

  1. MS-DOS real mode (*.SYS)
  2. Real mode Windows (usually listed in SYSTEM.INI, *.DRV)
  3. Protected mode Windows (virtual drivers - *.VXD or *.386)

If a device is not supported by a new driver, the MS-DOS driver in the CONFIG.SYS file is left in place and still works.

If the setup process is not sure that the driver may be safely removed, the driver remains in place and the 32-bit Windows-based driver is used after the switch to protected mode.

If the driver is not needed in the boot process, it may be removed from the CONFIG.SYS file. A real mode driver may be added by loading it through the CONFIG.SYS file.

However, protected mode drivers should be used whenever possible.

Protected Mode vs. Real Mode Drivers

Real mode drivers are drivers that were created to run under the real mode MS/DOS operating system. Real mode drivers are not as secure or robust as protected mode drivers.

Protected mode drivers take advantage of the architecture of the 80386 and higher processors' protected mode. A protected mode driver (also known as a virtual device driver, or VxD) allows for faster, shared access to the device with no use of the lower 640K of memory.

Driver Files

Most Windows-based drivers are located in the \WINDOWS\SYSTEM directory and are usually named *.DRV, *.386, or *.VXD. The .DRV drivers are older 16-bit Windows-based drivers, the .VXD and .386 drivers are 32-bit protected mode drivers.

VXD (32-bit protected mode) drivers that are always used in a specific Windows 95 installation are combined together by the setup process into the VMM32.VXD file to speed loading.

New system drivers, installed after Windows 95 is set up, are placed in the \WINDOWS\SYSTEM\VMM32 folder and are added into VMM32.VXD the next time Setup is run.

Note :Some third-party programs may use the .386 extension for their drivers. Windows 95 does support the use of these files.