For each boy a large kind of computer (8)
I believe the answer is:
personal
'kind of computer' is the definition.
'for each boy a large' is the wordplay.
'for each' becomes 'per' (I've seen this before).
'boy' becomes 'son' ('son' can be a synonym of 'boy').
'large' becomes 'l'.
'per'+'son'+'a'+'l'='PERSONAL'
(Other definitions for personal that I've seen before include "Pertaining to the self" , "Of one's private life - nobody else's business" , "Applied to a particular individual" , "Such a rude remark" , "Concerning the self" .)