Xref: utzoo comp.sys.ibm.pc:20515 comp.misc:3907 Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!iuvax!silver!silver.bacs.indiana.edu!regoli From: regoli@silver.bacs.indiana.edu (michael regoli) Newsgroups: comp.sys.ibm.pc,comp.misc Subject: DB25 to DB9 Serial Problems Keywords: serial ports, diablo 1640, pinouts Message-ID: <2521@silver.bacs.indiana.edu> Date: 24 Oct 88 20:52:22 GMT Sender: regoli@silver.bacs.indiana.edu Reply-To: regoli@silver.bacs.indiana.edu (michael regoli) Lines: 51 ]:[ would some kind soul figure out why this cable situation doesn't work? i'm trying to convert a DB-25 to a DB-9 interface. i have a diablo 1640 printer with a rs232 serial interface. the cable is hard-wired directly into the back of the printer, so all i'm working with is the male DB-25 coming out. it breaks out as follows: PIN# COLOR ASSUMED FUNCTION* ---- ----- ---------------------------- 1 green protective ground (GND?) 2 red transmit data (TD) 3 orange received data (RD) 4 yellow request to send (RTS) 5 brown clear to send (CTS) 6 blue data set ready (DSR) 7 purple signal ground (GND?) 8 white data carrier detect (DCD) 20 black data terminal ready (DTR) (*assuming the diablo cable is consistent with rs232 circuits--which it should be, since the printer works with any 25-pin PC serial port.) what i've done is connected the following pins: DB-25 -------------> DB-9 ----- ---- 1 (prot gnd) ? 2 (TD) 3 3 (RD) 2 4 (RTS) 7 5 (CTS) 8 6 (DSR) 6 7 (sig gnd) 5 8 (DCD) 1 20 (DTR) 4 what have i done wrong? i suppose i've have the wrong pin-outs for the 9-pin serial port. (and yes, i've configured the port with the DOS MODE command, too.) the computer is a true-blue IBM-AT (circa 1984). thanks for your help! -- | | michael regoli | ...rutgers!iuvax!silver!regoli | regoli@silver.bacs.indiana.edu | regoli@iubacs.BITNET |