Ethernet ports? What? If both machines have Ethernet, use that, don’t faff around with LocalTalk. Even crufty old 10-megabit Ethernet runs at around 4x the inherent speed of LocalTalk.
If you do need to use serial-port networking… As has been stated here repeatedly, the correct flavour of 8-pin serial cable run between the two printer ports is guaranteed to work. Software-wise, AppleTalk needs to be turned on and (when a choice is available) set to “printer port”. No further action should be required.
THAT SAID, having a network and actually using it for anything are two separate steps. No file servers will show up in the Chooser unless you first (1) turn on File Sharing and (2) explicitly tell the Finder to share a disk or folder, ON THE OTHER MAC. If you want both machines’ hard drives accessible from either one of them, you need to set up File Sharing on BOTH of them.
If you do need to use serial-port networking… As has been stated here repeatedly, the correct flavour of 8-pin serial cable run between the two printer ports is guaranteed to work. Software-wise, AppleTalk needs to be turned on and (when a choice is available) set to “printer port”. No further action should be required.
THAT SAID, having a network and actually using it for anything are two separate steps. No file servers will show up in the Chooser unless you first (1) turn on File Sharing and (2) explicitly tell the Finder to share a disk or folder, ON THE OTHER MAC. If you want both machines’ hard drives accessible from either one of them, you need to set up File Sharing on BOTH of them.