How can you use a dial up connection on a new computer that only has ethernet port and no telephone port?

Most computers still come with a phone jack expansion in one of the PCI slots, try plugging it into that, and ethernet cable into the onboard ethernet adapter. I dont use fax machines personally, so this is just a theory, but it should work. You will probably want to pick up an A/B splitter box with a manual switch at Radio Shack for like $10. Make sure the configuration is setup so the computer still has internet while you are faxing.