Path: news1.icaen!news.uiowa.edu!news1.chicago.cic.net!iagnet.net!207.22.81.9!europa.clark.net!4.1.16.34!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!howland.erols.net!news2.digex.net!swbell!not-for-mail From: Rubywand Newsgroups: comp.sys.apple2 Subject: Re: pinouts for null modem Date: Sun, 24 Aug 1997 12:47:13 +0000 Organization: Southwestern Bell Internet Services, Richardson, TX Lines: 38 Message-ID: <34002D51.75DA@swbell.net> References: <33ff685d.3917544@news.execpc.com> <33ff980f.100556186@news.tds.net> <33ffaedd.5499905@news.execpc.com> NNTP-Posting-Host: ppp-207-193-13-214.hstntx.swbell.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 2.02E (Win16; I) Bill Misek writes ... > > .... > So what pins from each of those gets wired together? > You plug a 9-pin --> 25-pin converter cable into the PC serial port you plan to use. The 25-pin side should be a male plug (to go to a modem). Your GS ("high-speed") modem cable should, also end in a 25-pin male plug. Your NULL modem is two 25-pin female sockets (call them "A" and "B") wired back-to-back as follows ... Socket-A Socket-B 1 -> 1 2 -> 3 3 -> 2 4 & 5 -> 8 6 & 22 -> 20 7 -> 7 8 -> 4 & 5 20 -> 6 & 22 If you can find a couple old-style DIN-25 plug casings, the sockets can be mounted and the casings can be glue-gunned together to make a nice compact unit. You plug the modem cable from the PC into one side of the NULL modem and the modem cable from the GS into the other side. Rubywand