Haphazard components of read-only memory (6)
I believe the answer is:
random
'haphazard' is the definition.
(similar in meaning)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for random that I've seen before include "Chance, irregular" , "Unsystematic" , "Wild" , "Haphazard, no fixed pattern" , "casual?" .)