My netowrk is a mix of OS X, OS 10, and RasPi (Buster, Bullseye, and Bookworm). I have on e or two favored machines that are only 9.x capable. They can see the internet enough to come to AppleFritter, MacRepository.com, and MacintoshGarden.com. They just cannot see anything on my local network, nor be seen by any local machine. Pinging the IP address gets a hit but trying to connect fails as there seems to be alack of a common protocol/protocol version.
What could I do to make these things see each other?
TIA
You'd need something like dave to reach a smb share. Classic MacOS doesnt speak SMB. it uses appleshare / AFP for its file sharing. Im not even sure that current linux's can even install anything that speaks appleshare or afp.
On raspbian/debian you may try "libatalk"
https://github.com/Netatalk/netatalk
Depends on what you want to do. If you need to share data between macos and modern machines, the easiest protocol both understand is NFS. If you use something like a synology NAS (or FreeNAS) you can share the same storage space with multiple protocols.
Way back when... I used to run an A/UX server specifically to map data between PCs, mac0s 9.x machines and Unix machines (before linus). The A/UX machine can mount the NFS volumes locally and then share them out via AppleShare. A bit of a kludge... but it worked.