Minimum memory required to execute program if overlay is applied

Question

In a system which supports overlay two programs want to run.

Size of program1 = 90kb

Size of program 2 = 100kb

Size of common code = 10kb

Size of overlay driver = 20kb

Size of error routine = 50kb

If no error is occured then what will be the minimum memory requirement to execute program

 

a) 130kb.                                       b)180kb

c) 270kb.                                       d) 220kb

Please give explanation also thank you.

Answer 1

Overlay can share same memory space for different programs

So, if we take large program , then both program could run

So, 100kB memory is taken

Common code size =10 kB

Overlay driver size 20kB

Error has not occured . So, no need to take space for error routing

So, total space required 100+10+20=130kB