Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!uunet!olivea!apple!netcom!hotcity!furmanm From: furmanm@hotcity.uucp (Michael Furman) Newsgroups: comp.sys.tandy Subject: Re: Need help connecting Tandy 200 to Mac 512K Message-ID: Date: 3 Mar 91 16:08:42 GMT References: <29028@cs.yale.edu> Organization: BBS Lines: 35 Bill: I just happen to have the pin-outs of thhe Mac 8-pin modem port. I can't find my RS-232C specs right now, so I may need to follow this message with the Tandy side of the connection to make sure it will work. What you need anytime that you are trying to connect any 2 computers that are different together, it is a good idea to have a RS-232 break-out box, and also, a line monitor ( you put it in line with the cable, and it tells you the activity on the major lines) You also will need a plug that goes into the Mac that has wires on the other end so that you can try different ways of connecting things. Here is the Mac pinout: Pin Function ------- ---------------------- 1 Handshake out 2 Handshake in 3 Transmit data minus (ground) 4 Signal ground 5 Recieve data minus 6 Transmit data plus 7 Status line (goes to DCD) 8 Recieve data plus What you need to do on the Mac, is turn the "handshake" off. It looks as if the Mac outputs are "current loop", and that gets a little bit complicated. The Tandy side is no problem, since it is standard RS-232. I don't know that much about the Mac, so, if anyone else can, add to this. You might also want to go to a Mac.hardware newsgroup and ask them. I hope that this is of some help. I do have more info, but I will need to find it while I'm offline, and call back with more info for you. By the way, you can get cables that convert RS-232 to Mac, but I'm sure that you have one of these allready, and that it probably didn't work. Michael Furman-- out here in "sunny" California (It's been raining since Wednesday-- for a longer time than since that beginning of the drought)