Another idea of the older computer would be to try & locate a vintage
AirPort express or extreme from the 802.11b/g/n era and use a split
connection from the router or cable box, etc so your other wi-fi base
can run a modern secure protocol, and the vintage computer can
run from the other compatible one.
Seems odd that I have a few spares of the series in reference, as
whenever I happened across duplicates of ones I bought new, I
got these spares for only a few dollars each; while having paid
over $150. for AirPort Extreme models at discount for ones I use.
So, some cost me as little as $2., two others $5. each. The model
Extreme offered Ethernet, USB2.0, in-out for wired internet. And
a fairly good range distance, essentially fair over line-of-sight.
I found that mine could run a USB printer as a wi-fi via the AEBS.
A friend was able to use a USB hard drive via the port on theirs
for storage, but that was not said to be supported. I tried one of
mine outdoors in a waterproof container, to expand a network.
The good thing about the AirPort Extreme (white orb, circa 2004)
is they had a 56k dialup modem, several extra ports, and can be
used to relay other wireless base stations like a repeater. Or with
an Express model, they can support several computers and they
need not all be running unsecured. The configurations of how to
do this now may be harder to discover, I used to have all that on
paper and also some great bookmarked sites. They're gone now.
The iMac G4 800 can run up to 1024MB RAM if the factory slot
is upgraded with a suitable 512MB chip and the lower slot also
to an appropriate spec 512MB chip. Each location uses different
type of RAM; and the factory slot is a very busy job to upgrade.
You could research the correct upgrade RAM for the user friendly
slot in the bottom (under metal plate) and have the iMac running
with 768MB Total, or 256+512. If at some future date the internal
battery is replaced (PRAM battery) that would be a fair time to
also have the RAM upgraded; be sure the RAM is of best quality
so as to not have odd failure because the RAM can act up badly
if that is not of high quality. I have experience in this kind of thing.
If the computer had 1024MB (1GB) RAM total, and checked over
to be sure it has stable hardware, perhaps some upgrade or new
items, it could run Tiger 10.4.11 as a fine last system. The iMac G4
800 17" that I had, with superdrive, airport, 56k modem, etc worked
well with Tiger 10.4.11; but still worked best with its own branched
wi-fi base station. And its own older 802.11b/ settings.
Sometimes it can be fun to be on the lookout for cool vintage hardware
and whatever software you can save from being tossed; to keep & use.
Glad to hear you were able to get the iMac G4 to work, so far...