PS. If you have a little more memory (possibly for 24M, probably for 32M)
you can get rid of the hard disk, as the software to operate a SETI@Home
machine will almost certainly fit on a single floppy Linux (Linux Router
Project style, or the rescue disk style that I use).
Complications are that the floppy would have to be customised for the
machine's networking environment and one could not distribute it with
setiathome program installed without negotiating licensing terms for this,
as the setiathome licence doesn't permit re-distribution. These mean that
you would need to construct a configuring tool, possibly under Windows,
and that would be nearly all the effort.
A simple single disk solution would not save state so would lose any
batch that was incomplete when it was shutdown. This could be added, but
running with the actual state files on the floppy would probably wear it