I were supposed to write a mini howto on how to do that, but there is something wrong with my Plus so I haven't managed to get the pictures I wanted xx(
As I said you need 6.0.8, MacTCP and MacPPP in the control panel. I think I configured MacTCP to static IP 192.168.0.50 on the Plus. I then plugged in a serial cable into the modem port on the Plus, and connected it to a laptop running linux/osx. I think I used a serial to usb converter on the machine in the picture. It was running Ubuntu at the time.
I installed
pppd in linux, and played around with the config so I could get a connection and a route from the serial port to my WIFI (using the laptop's wifi/LAN ip).
I saved the command in a small script, so I still have it;
Code:
sudo pppd -detach crtscts lock debug defaultroute proxyarp 192.168.0.10:192.168.0.50 /dev/tty.usbserial 38400
192.168.0.10 is the laptop's local LAN IP, 192.168.0.50 is a random static IP I sat up in MacTCP.
I think that's about it. I then hit the "Connect" button in MacPPP and could browse the web.
It's also possible for pppd to give out an ip to the plus (DHCP) etc, but as I said the machine isn't working so I haven't played with the config for a few years..
A Tip; Set up a web server on the laptop or use ping to see if you can get a connection before you start browsing the web, you may have to enter a router IP in MacTCP or something to reach anything beyond your local LAN.
I'm going to try and recap the Plus in the holidays so I will fix a better howto (with pictures) later.