The latest version of DJGPP (a port of GCC to MS-DOS running on an i386
or i486) can be found on omnigate.clarkson.edu in /pub/msdos/djgpp via
anonymous FTP.  Both sources and binaries are available there.
The latest version of DJGPP (a port of GCC to MS-DOS running on an
i386 or i486) can be found on oak.oakland.edu in /pub/msdos/djgpp (or
any other local Simtel mirror site) via anonymous FTP.  Both sources
and binaries are available there.

You can also get DJGPP on CD-ROM from the FSF.  Ask 
gnu@prep.ai.mit.edu for details.