Second professor retains copyright on latest gadget (3,3)

'gadget' is the definition.
(I know that mod con is a type of gadget)

'second professor retains copyright on' is the wordplay.
'second' becomes 'mo' (both are short periods of time).
'professor' becomes 'don' (term for a university professor).
'retains' is an insertion indicator.
'copyright' becomes 'C' (as in the copyright symbol, a C in a circle).
'on' means one lot of letters go next to another.
'don' placed around 'c' is 'dcon'.
'mo'+'dcon'='MOD CON'

'latest' acts as a link.
This may not be correct. It may belong to another bit of the clue.

Can you help me to learn more?