I recently obtained a little gadget that some of you may or may not know about, it's called a Lantronix UDS-10. It can get your old Classic Computer on the Internet. It acts like a modem, but it handles all the telnet protocols internally. One end hooks up to your classic computers RS-232, the other end uses an Ethernet cable and plugs into your router.
I was amazed to find "GOBS" of active BBS's on the Internet.
In my gallery << HERE >> you can see some images of the unit and a screen shot of the TI connected to one of the BBS's.
<< HERE >> Is the eBay search string.
Sometimes you might have to wait a week or two to find a good, but you should be able to get one under $30.00 (shipping included) if you are patient.