kevin@harvard.UUCP (Kevin Crowston) (02/25/86)
Does anyone know if the 9 pin serial connector on a PC-AT
(specifically, the port on an AST Advantage! card) is RS-422
or more particularly, the same layout as on a Macintosh?
Can anyone post or repost a mapping from the AT's 9 pins
to (say) the 25 pins of an RS-232 DTE connector?
Kevin Crowston
MIT Sloan School of Management
kevin@xv.mit.edu
kevin@harvard.harvard.edu
--
Kevin Crowston UUCP: {seismo,ut-sally}!harvard!kevin
MIT Sloan School of Management ARPA: kevin@xv.mit.edu or
kevin@harvard.arpamason@noscvax.UUCP (Nicholas B. Mason) (02/25/86)
In article <734@harvard.UUCP> kevin@harvard.UUCP (Kevin Crowston) writes: >Can anyone post or repost a mapping from the AT's 9 pins >to (say) the 25 pins of an RS-232 DTE connector? PC 9 pin to 25 pin connection 1 ---- 8 2 ---- 3 3 ---- 2 4 ---- 20 5 ---- 7 6 ---- 6 7 ---- 4 8 ---- 5 9 ---- 22 Also, if you want to connect the second serial port on the Advantage card but did'nt buy the AST cable. Connector J3 on the Advantage card is the output for the second serial port. It has two rows of 5 pins. Assuming the pins are numbered as: 6 7 8 9 10 <---J3 on AST 1 2 3 4 5 Advantage card then pin 1 is DCD 2 RxD 3 TxD 4 DTR 5 signal gnd 6 DSR 7 RTS 8 CTS 9 RI 10 ??? Hope this helps... Nick Mason NOSC San Diego , CA mason@nosc or ihnp4 \ akgua \ decvax ------------------!sdcsvax!noscvax!mason dcdwest / ucbvax /
sum@uiucdcsb.CS.UIUC.EDU (02/26/86)
/* 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.edujrv@siemens.UUCP (02/27/86)
>/* Written 2:22 pm Feb 25, 1986 by mason@noscvax in siemens:net.micro.pc */ >In article <734@harvard.UUCP> kevin@harvard.UUCP (Kevin Crowston) writes: >>Can anyone post or repost a mapping from the AT's 9 pins >>to (say) the 25 pins of an RS-232 DTE connector? > >PC 9 pin to 25 pin connection > > 1 ---- 8 > 2 ---- 3 > 3 ---- 2 > 4 ---- 20 > 5 ---- 7 > 6 ---- 6 > 7 ---- 4 > 8 ---- 5 > 9 ---- 22 I do not agree with this mapping. It looks like a mapping to a DCE 25 pin connection and not DTE as was requested. PC 9 pin 25 pin DTE connection 1 (Carrier Detect) <------------ no connection 2 (Data Input) <---------------- 2 - TxD (Transmit data) 3 (Data Output) ---------------> 3 - RxD (Received data) 4 (DTR) ------------------+----> 6 - DSR +----> 8 - CD (carrier detect) 5 (Signal Ground) -------------- 7 - SGND (Signal Ground) 6 (DSR) <----------------------- 20 - DTR 7 (RTS) ----->+-loop loop-+<--- 4 - RTS 8 (CTS) <-----+ +---> 5 - CTS 9 (Ring indicator) <------------ no connection If you are going to be running interrupts on the serial port then you might want to tie pins 1 and 9 to pin 4 to prevent any spurious interrupts from ocurring. This is the connection I used recently to connect a VT220 to the AT serial port. (Actually, I tied pins 1, 6, 9 to pin 4 and made DTR active. On the 25 pin DTE side I connected pin 6(DSR) and 8(CD) to pin 20(DTR) to get things going.) If you have any problems get in touch with e-mail. Jim Vallino {allegra,ihnp4}!princeton!siemens!jrv