Everybody say "hoo-ray" for progress
So I looked up some information on gzip file formats, and learned enough to determine that gzip archives start with the byte pattern "1f8b". So I grabbed one an upgrade image, opened it up in ghex, and did a search for such. Found it at 7E80. Decided it was likely the compressed image considering a large number of bytes preceding this were all 00. So I chopped off everything before that point, ran it through gzip (which complained of trailing garbage) and ran the result through strings.
An exerpt from the result:
`Easy Rider - Rel. 1.0a
Copyright (C) 1996-1997, Teknema, Inc.
Init Video........ OK
Init I/O copro....
%dk in %d sectors
It goes on for much longer than that, but there's definitely something embedded in there. Time to go poke around some more.