The operating system keeps a record of where each program and its data are stored in main memory.
State two reasons why the operating system needs this record.
Mark scheme
Award one mark for any of the following up to a maximum of two marks:
- So that it does not overwrite/use memory that is already being used by another program (1)
- So that it can find the program/data again when the program needs it (1)
- So that it knows which memory locations are free/can be allocated to a new program (1)
- So that it can keep the data used by each program separate from other programs (1)
- So that it can free the memory when the program is closed/knows which memory to release (1)
Do not accept 'so the program runs faster'.
Do not accept 'so that the program is not lost when the power is turned off' (this is about saving files to secondary storage, not main memory).
Example answers and how they were marked
So that the operating system does not put a new program on top of memory that another program is already using, and so that it can find the data again when the program needs it.
Why: Creditworthy point 'does not overwrite memory used by another program' (1) and 'find the program/data again when needed' (1).
It knows where the program is so it can find it again when it needs to run it.
Why: Creditworthy point 'find the program/data again when it is needed' (1); no second reason given.
So that the program is not lost when the computer is switched off.
Why: This is about saving to secondary storage, not about a record of main memory locations; not a creditworthy reason, so no marks.