  Supernovae and their remnants are believed to be prodigious sources of
Galactic cosmic rays and interstellar dust. Understanding the mechanisms behind
their surprisingly high production rate is helped by the study of nearby young
supernova remnants. There has been none better in modern times than SN1987A,
for which radio observations have been made for over a quarter of a century. We
review extensive observations made with the Australia Telescope Compact Array
(ATCA) at centimetre wavelengths. Emission at frequencies from 1 to 100 GHz is
dominated by synchrotron radiation from an outer shock front which has been
growing exponentially in strength from day 3000, and is currently sweeping
around the circumstellar ring at about 4000 km s$^{-1}$. Three dimensional
models of the propagation of the shock into the circumstellar medium are able
to reproduce the main observational features of the remnant, and their
evolution. We find that up to 4% of the electrons encountered by the shock are
accelerated to relativistic energies. High-frequency ALMA observations will
break new ground in the understanding of dust and molecule production.
