A student uses a graphics tablet connected to a computer to draw in a program.
Describe how the operating system passes input from the graphics tablet to the program.
Mark scheme
Award up to two marks for a linked description such as:
- The operating system receives signals/data from the graphics tablet (1) and converts them into data the program can use/process (1)
- The operating system receives data from the graphics tablet (1) and passes/forwards it to the program being used/the active program (1)
- The tablet's device driver receives/interprets the signals/data from the tablet (1) so the operating system can pass the input to the program (1)
- The operating system identifies the graphics tablet as the source of the input (1) so the data is sent to the correct program (1)
Accept 'signals' for 'data' throughout.
Accept reference to the device driver only where it is linked to receiving/interpreting the input (e.g. the driver receives the tablet's signals (1) so the OS can pass data to the program (1)).
Do not accept 'the operating system uses a driver' on its own, without saying what the driver does with the input.
Do not accept generic statements such as 'the operating system runs the tablet' as a description of how input is managed.
Do not accept responses that say the operating system creates/finishes the drawing, or that the tablet stores the input permanently.
Example answers and how they were marked
The operating system receives signals from the graphics tablet and passes the data to the program.
Why: Receives signals/data from the tablet (1) and passes the data to the active program (1).
The operating system receives signals from the graphics tablet.
Why: Gives the first half of a linked description (1): it receives signals, but does not say what happens to the input.
The operating system uses a device driver to control the graphics tablet and stores the input.
Why: Only says the OS uses a driver to control the tablet and that input is stored; it does not describe the driver receiving/interpreting the input or the input being passed to the program, so no linked point is credited. The mark scheme rejects 'uses a driver' on its own.