Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!apple!jdevoto From: jdevoto@Apple.COM (Jeanne A. E. DeVoto) Newsgroups: comp.sys.mac.comm Subject: Re: null modeming Message-ID: <47632@apple.Apple.COM> Date: 30 Dec 90 05:51:29 GMT References: Distribution: usa Organization: Apple Computer Inc., Cupertino, CA Lines: 29 In article dpaight@weber.ucsd.edu (Daniel Paight) writes: >Sorry if this is the 4.23e06 time this question has been raised >here, but I need someone to tell me how to null modem. My >father-in-law has bought a Mac and needs to move his data files from >a CP/M Kaypro to the Mac. I thought null modeming sounded like a >promising way to go, but I'm ignorant about electronics and such and >am afraid I might blow up his new Mac! :) > >I understand only this much: that I need a special cable to connect >the Mac modem port directly to the Kaypro's RS232. I have found a >source for the cable, but I'd like to find out what I'm getting into >before pursuing this any further. Please help! A serial port has separate lines for transmit and receive. A "null modem" simply reverses these lines, so that the transmit pin on one end is connected to the receive pin on the other end. (The lines used for handshaking will be flipped also, if they're connected.) This means that what you send from one computer gets sent to the "receive" pin on the other computer. All it is is a special kind of cable. No possibility of blowing anything up. -- ========= jeanne a. e. devoto ======================================== jdevoto@apple.com | You may not distribute this article under a jdevoto@well.sf.ca.us | compilation copyright without my permission. ______________________________________________________________________ Apple Computer and I are not authorized | CI$: 72411,165 to speak for each other. |