Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!dali.cs.montana.edu!uakari.primate.wisc.edu!aplcen!boingo.med.jhu.edu!haven.umd.edu!socrates.umd.edu!MIKE@UC780.UMD.EDU From: mike@UC780.UMD.EDU (Mike Santangelo) Newsgroups: comp.sys.dec Subject: Re: KA820 processor's serial lines, what use? Message-ID: <1991Apr29.224242.10516@socrates.umd.edu> Date: 29 Apr 91 22:42:42 GMT References: <1991Apr26.181122.12239@iplmail.orl.mmc.com>,<3i3213w163w@zl2tnm.gp.co.nz> Sender: news@socrates.umd.edu (News) Reply-To: mike@UC780.UMD.EDU Organization: The University of Maryland, University College Lines: 54 In article <3i3213w163w@zl2tnm.gp.co.nz>, don@zl2tnm.gp.co.nz (Don Stokes) writes: >carlm@iplmail.orl.mmc.com (carl morris) writes: > >> The lab I work for recently inherited a VAX 8350 system. Looking through >> the KA820/KA825 Processor Technical Manual that came with it, one of my >> maintenance gurus came across a section (page 2-8) that references four >> serial line units which are on the cpu board. There must be some reason >> for putting those ports on the board ("Hey, Bob, we got this corner left >> over on the cpu board..."), anyone have any ideas? Was it primarily for >> maintenance diagnostic access, or are there some useful end-user type >> uses for them? > >They're (sort of) perfectly usable serial ports. You know, those silly >things that send and receive data one bit at a time? 8-) > >Seriously, one of them is the console port -- all VAXes have at least >one console port. Under VMS, this is referred to as OPA0:. The >remaining three ports are available to you to do as you like with them. >VMS doesn't enable them by default -- you can enable them with the >following commands (from a suitably privileged account; we do this at >system startup time): > > $ MCR SYSGEN > SYSGEN> CONNECT SLU=1 > SYSGEN> CONNECT SLU=2 > SYSGEN> CONNECT SLU=3 > SYSGEN> EXIT > >You now have three devices called TCA0:, TCB0: and TCC0:. > >Note that these devices are pretty dumb, and interrupt the CPU at a >fairly high priority. Heavy use is *not* recommended. High speeds >aren't a good idea, although they do work. Your milage may vary... > > >Don Stokes, ZL2TNM / / don@zl2tnm.gp.co.nz (home) >Systems Programmer /GP/ GP PRINT LIMITED Wellington, don@gp.co.nz (work) >__________________/ / ---------------- New_Zealand__________________________ One question though, from a person who doesn't have a KA820 based VAX, but maybe they would be cheap enough to get on the 3rd party used DEC hardware market... Do these ports have connectors to go along with them? Like DB25 based RS232? Or are they something you have to fudge around with on the processor board to bring out. Inquiring minds want to know :^) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Michael F. Santangelo + Inet: mike@uc780.umd.edu VMS / UNIX Systems + mike@socrates.umd.edu Academic Computing UMUC + Bnet: MIKE@UC780 (The University of Maryland, + MIKE@UMUC (not visited often) University College) +