| Date | November 2021 | Marks available | 3 | Reference code | 21N.1.HL.TZ0.8 |
| Level | HL | Paper | 1 | Time zone | no time zone |
| Command term | Explain | Question number | 8 | Adapted from | N/A |
Question
Explain how an operating system manages peripherals.
Markscheme
Award [3 max]
OS keeps tracks of all peripheral devices (the I/O controller) / decides which process gets the device when and for how much time / allocates and de-allocates devices;
OS works with device drivers and the basic input/output system (BIOS) to perform hardware tasks
/ the necessary drivers (for every peripheral) are built into the OS and/or when a new peripheral is added software / device driver provided by a hardware maker is installed into the operating system (to tell the computer's OS how to work with the peripheral/hardware) (because without a device driver the OS would not be able to communicate with this peripheral device);
A device driver translates the OS's instructions into a language (analogue signals) that the device can understand;
There are various types of device drivers for peripherals (such as keyboards, mice, disk drives, controllers, printers, graphics cards, ports, etc.);
Device drivers run in the OS kernel space (in the part of the OS that directly interacts with the physical structure of the system) (and implement functions such as open, close, read, write);
The running application/user's program can make a call to device driver functions which provide an interface between user space and kernel space;
Example answer:
An OS manages peripherals via their respective drivers;
For example, sound card drivers;
are necessary so the OS knows exactly how to translate the 1s and 0s (that comprise the MP3 file) into audio signals;
that the sound card can output to headphones / speakers;
Examiners report
A well answered question. Many comprehensive answers were seen.
