Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles $Revision: 1.7.0.10 $; site uiucdcsb Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!ihnp4!inuxc!pur-ee!uiucdcs!uiucdcsb!sum From: sum@uiucdcsb.CS.UIUC.EDU Newsgroups: net.micro.pc Subject: Re: 9 pin serial port on PC AT Message-ID: <5100124@uiucdcsb> Date: Wed, 26-Feb-86 11:11:00 EST Article-I.D.: uiucdcsb.5100124 Posted: Wed Feb 26 11:11:00 1986 Date-Received: Sat, 1-Mar-86 02:50:37 EST References: <734@harvard.UUCP> Lines: 59 Nf-ID: #R:harvard.UUCP:734:uiucdcsb:5100124:000:2092 Nf-From: uiucdcsb.CS.UIUC.EDU!sum Feb 26 10:11:00 1986 /* Written 4:36 pm May 14, 1985 by kevinp@mmintl.UUCP in uiucdcsb:net.micro */ In response to the recent inquiries concerning the IBM PC AT Serial/Parallel Adapter I have posted the following: The IBM PC AT Serial/Parallel Adapter has a 9-pin D shell type connector which is configured as follows: Pin Signal Name (DCE) RS-232C Pin (DCE) ----- -------------------- ------------------- 1 Carrier Detect 8 (CD) 2 Received Data 3 (RD) 3 Transmitted Date 2 (TD) 4 Data Terminal Ready 20 (DTR) 5 Signal Ground 7 (SG) 6 Data Set Ready 6 (DSR) 7 Request To Send 4 (RTS) 8 Clear To Send 5 (CTS) 9 Ring Indicate 22 (RI) The above is for attachment to Data Communications Equipment such as a modem. To attach to another terminal (DTE) device the following signal lines must be changed: Pin Signal Name (DCE) RS-232C Pin (DTE) ----- -------------------- ------------------- 2 Recieved Data 2 (TD) (RD & TD Swapped) 3 Transmitted Data 3 (RD) 4 Data Terminal Ready 6 (DSR) (DTR & DSR Swapped) 6 Data Set Ready 20 (DTR) / 7 Request To Send 4 (CTS) \ (Pins jumpered together at \ 8 Clear To Send 5 (RTS) / each end only in pairs. Pin 7 to 8, 4 to 5. Not needed for Full-Duplex operation.) This information may be obtained from the IBM Technical Reference, Options and Adapters Mannual, Volume 2 after installing update pages which are actually provided in the Technical Reference, Personal Computer AT Mannual. This means you need the AT tech ref to get the specification if you haven't already obtained one. Note: I agree that IBM makes it difficult to obtain technical info. I would explain, but this is the wrong place for that flame. -- Kevin Piette Phone: (203) 522-2116 Multimate International Corporation, Research & Development UUCP: ...!seismo!cmcl2!philabs!pwa-b!mmintl!kevinp /* End of text from uiucdcsb:net.micro */ I am not expert but this has been helpful. -- Bob USENET: {convex,ihnp4,pur-ee}!uiucdcs!sum CSNET: sum@uiuc.csnet ARPA: sum@b.cs.uiuc.edu