This is an interesting program used to test memory that boots from a floppy. Might be good someday for figuring out how to bootstrap a homemade OS.
The home page for the program is: http://reality.sgi.com/cbrady_denver/memtest86/. From there you can download a precompiled binary or the source code. I'll attach the version we used in case the website ever disappears.
-- MattWalsh - 02 Jan 2002