pat@seradg.Dayton.NCR.COM (Patrick Pesch) (12/11/87)
A friend of mine recently gave me a US Robotics PASSWORD/COURIER 300/1200 bps modem. The problem is that the cabling coming out of the unit is for an Osbourne box, which means that it is a DB9 connector (9-pin) with only 4-wires actually attached. I opened up the case and found that the internal end of the cable is connected to a 9 (or 10?) pin "edge connector". Does anyone out there know which pins are which on the edge connector? What I want to do is to attach this guy to a vt100 type terminal with a DB25 connector. Do I have to get a hold of US Robotics and purchase a cable from them or can I *easily* build one myself? I am not a "hardware type", but feel I could build my own if I what pin did what on the edge connector inside the modem... Thanks in advance for any advice... Patrick Pesch pat@seradg.Dayton.NCR.COM NCR Corporation Dayton OH
silber@batcomputer.tn.cornell.edu (Jeffrey Silber) (12/11/87)
Last time I needed to make a cable for a US Robotics modem, I called
US Robotics' tech support and they supplied me with all of the appropriate
pin-outs (I needed to go from a mac DB9 to the DB25 on the Password modem).
--
"A billion here, a billion there, and pretty soon you're talking real money."
--Sen. Everett Dirksen
Jeffrey A. Silber/silber@tcgould.tn.cornell.edu
Business Manager/Cornell Center for Theory & Simulation in Science & Engineeringehr@ecsvax.UUCP (Ernest H. Robl) (12/12/87)
On AT-type machines the pins on a DB9 serial connector are: 1 CD 2 RD 3 TD 4 DTR 5 Sig.Grnd. 6 DSR 7 RTS 8 CTS 9 RI For straight-through cables DB9 on computer to DB25 on modem, we have used the following: DB25 side DB9 side pin 2 to pin 3 pin 3 to pin 2 pin 4 to pin 7 pin 5 to pin 8 pin 7 to pin 5 pin 8 to pin 1 pin 20 to pin 4 pin 22 to pin 9 For a null-modem (DB9 computer to DB25 computer) we have used the following: DB25 side DB9 side pin 2 to pin 2 pin 3 to pin 3 pins 4&5 to pin 1 pin 6 to pin 4 pin 7 to pin 5 pin 8 to pins 7&8 pin 20 to pin 6 pin 22 to pin 9 Since you are going from a DB9 modem to a DB25 machine, the above may or may not work. Some electronics stores, including Radio Shack computer centers now sell DB9 to DB25 adapters. I presume they are wired as in the first example above. Hope this helps. -- Ernest -- My opinions are my own and not necessarily IBM-compatible.--ehr Ernest H. Robl (ehr@ecsvax) (919) 684-6269 (w) Systems Specialist, Library Systems, (919) 286-3845 (h) Perkins Library, Duke University, Durham, NC 27706 U.S.A.
zog@laidbak.UUCP (Christian G. Herzog) (12/13/87)
The original question was related to a particular type of USR modems and was not really a generic 9->25 pin adaptor question (even though the article which contained the wiring setups for the AT-style connectors is a really excellent reference to keep around for those occasions): The problem here is that the DB9 on the Password modems IS NOT an AT-style connector. The DB9 was intended to connect to an Osborne-1 which was designed to use TTL rather than RS232 signal levels to communicate with the modem. The Password series modems were all the same but came with enough pins on the inside connector to allow both a straight TTL I/O (bypassing the line drivers and receivers which perform the logic translation) rather than the more conventional +/- 12 volt RS232 levels. From the 12 pin header INSIDE the modem to an outside RS232 connection should be as follows for the Password/Courier modems: Connector: 1 | Unused 2 | " 3 | " 4 | pin 3 (on a DB25) 5 | pin 7 6 | pin 6 7 | pin 12 8 | pin 22 9 | pin 8 10| pin 5 11| pin 2 12| pin 20 ^ ^ This is the ridge on the connector which allows the mating connector to plug in with the correct orientation. __ __________ __ | ||_______ ||__| Christian G. Herzog | | _______| | __ | || ____ || | {ihnp4,sun}!laidbak!zog | || |____| || | | ||__________|| | Lachman Associates, Inc. | |___________ | | |______________||__|
dhp@ihlpa.ATT.COM (Douglas H. Price) (12/19/87)
Sorry, you can't use the DB9 connector on the Osborne I for connecting to any other modem than the 300 baud one that Osborne sold itself. All the signals are not present. You have to use the DB25 connector on the front of the Osborne instead. If you have a printer connected to this port, you're outta luck. -- Douglas H. Price Analysts International Corp. @ AT&T Bell Laboratories ..!ihnp4!ihlpa!dhp