> > Is there an easy way to tell, if a serial cable is > a null modem cable?
> A nullmodem cable has two female plugs. Usually were, should have been, two female plugs, but some were specially built for non-conforming DTEs that had female plugs on the Data Terminal Equipment, and thus had one of each -- and even back then these were impossible to recognize unless labelled. The once-ubiquitous Laplink cable has two female DB25s and one female DB9 at one end, like Zapod Beeblebrox, and has a couple extra pin swaps besides the basic null modem swaps, but works fine for most null-modem work. (I've got one attached between an AlphaServer 400 4/233 and a ancient NCR notepad as console terminal at the moment.) If you have a Digital-Volt-Ohmmetter or continuity tester, you can try ringing pin 2,3 to pin 2,3 at the other end. 2-2, 3-3 is "normal", 2-3, 3-2 is Null Modem. (If either device wants "hardware flow control", other pins need to be crossed or jumpered as well. Xon/Xoff flow control is much safer, same as with cheap, 4 wire serial cables.) In the old days, we had small DB25 M-F extenders with LEDs wired in that would light up to indicate correct wiring. Some had switches to compose a custom null-modem. A null-modem how-to is buried under the Linux Emacs how-to, go figure. http://howtos.linux.com/howtos/Emacspeak-HOWTO/appendixa.shtml Null modem adapters (to go on an existing cable) and cables are still available in at better retailers. Bill __________________________________ Do you Yahoo!? Yahoo! Mail - Find what you need with new enhanced search. http://info.mail.yahoo.com/mail_250 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
