Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!wuarchive!zaphod.mps.ohio-state.edu!mips!sprint!brudley From: brudley@mips.COM (Brett Rudley) Newsgroups: comp.sys.mips Subject: Re: login and syslog question. Message-ID: <40951@mips.mips.COM> Date: 19 Aug 90 23:31:22 GMT References: <24581@boulder.Colorado.EDU> <905@hadron.COM> Sender: news@mips.COM Reply-To: brudley@mips.COM (Brett Rudley) Organization: MIPS Computer Systems, Inc. Lines: 57 In article <905@hadron.COM> jsdy@hadron.UUCP (Joseph S. D. Yao) writes: >In article <24581@boulder.Colorado.EDU> hartzell@beagle (George Hartzell) writes: >>I have two related problems/questions. ... >> ... I have 48 serial lines strung out through a large >>building (almost certainly out of rs232 spec). ... >>turned off login/getty tries to log in "people" with names like >>"mkmkk[m[". ... > ... > >Your best fix is to use cables that tie the DTR (Data Terminal Ready) >lead of your remote terminal or terminal emulator to the DSR (Data Set >Ready) lead of your serial port. Then tell your serial board (if you >can) that this is a "modem" port, and so should be ignored while the >DSR lead is not on. Many people figure they are winning by tying >together pins 1 (FRAME ground) and 7 (SIGNAL ground), which is quite >illegal by the standard, or leaving pin 1 off entirely; and by putting >a lump of solder over pins 4, 5, 6, 8, 20, and 22, to keep the line up >all the time. What they win in copper savings, they lose in aggravation >such as yours. The DEC 1976 Peripherals Handbook is the last one that >had a nice diagram of which pin should be crossed with what in a "null >modem" - type cable; I try not to remember these things any more. > Yes, I agree using a modem port is a good idea. However MIPS ports do not pay any attention to DSR, they only watch DCD to decide whether or not to complete an open on a modem port. This really should not matter however because a 'standard' null modem will tie DTR (pin 20) to both DSR (pin 6) and DCD (pin 8). On MIPS machines, serial ports can be accessed as either local or modem ports. Device files that refer to the port with a minor number of < 128 (high bit off) are local. If the device file refers to that port with a minor number > 127 (high bit on), it is a modem port. These ports usually have the letter 'm' to signify it is a modem port, ie: crw-rw-rw- 1 root bin 0, 1 Jun 8 08:38 /dev/tty1 crw-rw-rw- 1 root bin 0,129 Jun 8 08:38 /dev/ttym1 Your gettys will now ignore any input until you activate the port on your MAC and it turns on DTR. > Joe Yao jsdy@hadron.COM > ( jsdy%hadron.COM@{uunet.UU.NET,decuac.DEC.COM} ) > arc,arinc,att,avatar,blkcat,cos,decuac,\ > dtix,ecogong,grebyn,inco,insight,kcwc, \ > lepton,lsw,netex,netxcom,phw5,research, >!hadron!jsdy > rlgvax,seismo,sms,smsdpg,sundc,telenet, / > uunet / >(Last I counted ...) -- Brett Rudley {ames,decwrl,pyramid,prls}!mips!brudley MIPS Computer Systems - or - 930 Arques Avenue brudley@mips.com Sunnyvale, CA 94086 (408)524-8151