Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!sdd.hp.com!cs.utexas.edu!uwm.edu!linac!att!news.cs.indiana.edu!ariel.unm.edu!nmsu!dante!thbaca From: thbaca@nmsu.edu (BACA) Newsgroups: comp.sys.handhelds Subject: Re: HP 95LX and modem. Message-ID: <1620@opus.NMSU.Edu> Date: 26 Jun 91 23:52:37 GMT References: <25590176@hpcvra.cv.hp.com.> Sender: news@NMSU.Edu Organization: New Mexico State University Lines: 42 In article <25590176@hpcvra.cv.hp.com.> everett@hpcvra.cv.hp.com. (Everett Kaser) writes: >I'm a little weak on this area, but, how's it not working? No response? >If you're using the 9-pin to 25-pin converter, you may need to also use >a null-modem (swapper) in order to talk to the modem. The cable is set >up for talking to a PC (which is the same as talking to a modem, sort of), >but I think that the 9 to 25 converter swaps xmit and rcv so that it can >be used for connecting to a printer. So then you need another 25 pin to >25 pin "swapper" to put xmit and rcv back in the right place for a modem. > >On the other hand, I could be all wet. I think you had the right idea, but the details were just a bit off. The HP cable is a null-modem cable for "talking" to a PC, but the 9-pin to 25-pin converter is wired straight through. This allows the user to connect to either a 9-pin AT or 25-pin XT serial port. A modem, on the other hand, requires a "straight through" connection. This means that you need ANOTHER null-modem connector to "undo" the null-modem connection of the HP cable. A visual aid: NULL-MODEM HP Cable CONNECTOR xmit --------\ /-------- --------\ /-------- xmit \ / \ / HP95LX X X MODEM / \ / \ rcv _______ / \________ _______ / \________ rcv I hope this makes some kind of sense. On the other hand, I may be the one who's all wet. >Everett Kaser Hewlett-Packard Company >...hplabs!hp-pcd!everett work: (503) 750-3569 Corvallis, Oregon >everett%hpcvra@hplabs.hp.com home: (503) 928-5259 Albany, Oregon Thomas L. Baca NMSU