Device Drivers
Definition
A device driver is a piece of software that acts as a translator between the Operating System and a specific hardware device. It converts generic OS commands into the specific instructions that a particular device understands.
Why Drivers Are Needed
Different hardware devices, even devices that do the same job, use very different underlying technologies. For example, three types of printer all produce printed output, but their mechanisms differ entirely:
| Printer Type | Mechanism |
|---|---|
| Inkjet | Sprays droplets of ink onto the page |
| Laser | Magnetises areas of a drum; toner fuses to the page |
| Plotter | Uses a pen physically drawn across the page |
Without a driver, a “print” command from the OS would mean nothing to any of these devices. The driver translates the generic “print this document” instruction into the precise, low-level commands that each printer model understands.
How Drivers Work
Application (e.g. Word)
│
│ "Print document"
▼
Operating System
│
│ Generic print instruction
▼
Device Driver ◄── translates to device-specific commands
│
│ Machine-specific instructions
▼
Hardware Device (printer, mouse, keyboard…)
Key Points
- Every piece of hardware needs a driver: printers, mice, keyboards, monitors, graphics cards, network adapters
- Drivers are often installed automatically by the OS or come on a disc with new hardware
- An outdated or missing driver causes the device to malfunction or not work at all
- Driver updates can improve performance and fix security vulnerabilities
Exam Questions
Q: Why are device drivers necessary for peripheral hardware?
They translate the operating system’s general-purpose instructions into the specific commands that a particular piece of hardware understands, allowing the OS and applications to use any device correctly.
Q: A user connects a new printer. Explain the role of a device driver.
The device driver acts as a translator, it converts the OS’s generic print command into the specific instructions that this printer’s hardware can understand and execute.
Exam Tip
The key word is translator. A device driver translates between the OS (which speaks in general terms) and the hardware (which only understands its own specific language).