ANSI C to 'OLD' C

[y w ko]

Hi,
	I would be most grateful if someone could help me get hold
of a utility to convert 'C' source written with ANSI style
function prototypes to old style 'C'. I seem to remember
vaguely that there is something called 'unproto' which does
what I want.
	By the way, apart from GCC or Cfront (well, or using the above
mentioned utility), is that any other means of compiling 'C' 
code with function prototypes on the SUN's.
	Thanks in Advance!

						ywko