I had an OG 100 for a time, and liked it considerably. HOWEVER, it was 'way too hard to read except in direct sunlight (and I gave it away to a friend with younger eyes). There's a context-sensitive help function that tells you quite a bit, and experimentation will provide the rest.
I don't have any manuals; what I do have, however.... When I first got the beast, I downloaded everything I could find (based upon the idea that what you see on the Internet today, might not be around tomorrow). So if you might have an ftp site for it (email me the details privately), I could share my 43,611,884_bytes of unsorted, unverified, unsupported, applications and ebooks (I was fascinate by the ebooks, but you need GeoWorks Bindery to roll-your-own, and that hasn't been available anywhere for years), maybe as a very big ZIP file, but whatever. And because it's mostly uncategorized, I'm sure there are significant duplications here and there....
Alternately, you can cruise through Google & friends, and find it yourself.
And lastly, there's a Yahoo group devoted to GeoWorks, moderated by Byron Collins (bcollins@ clarksville.com). It seemed moderately active, but the OG 100 was mostly a "sideline"....
gk
:)