On Thursday 26 February 2009 11:34, William L. Maltby wrote:
> On Thu, 2009-02-26 at 06:14 -0500, Phil Schaffner wrote:
> > On Thu, 2009-02-26 at 10:17 +0000, Anne Wilson wrote:
> > ><snip>
> > >
> > > There is just one serial connector on the computer, so I set it to
> > > monitor /dev/ttyS0. Either that is wrong, or communication is
> > > failing. I've been told to try minicom to monitor it, but I'm not
> > > familiar with minicom (or any similar app), so again, I may be wrong in
> > > the way I'm trying to use that. I was told that unconnecting the
> > > device, then re-connecting it should give me a raft of output to the
> > > terminal - I saw nothing.
> > >
> > > Could someone please give me idiot-level instructions on how to tell
> > > whether I'm connecting to the correct port, or whatever other
> > > information I need?
> >
> > Anne,
> >
> > Are you sure the cable is correct? I recall in the past having trouble
> > with an APC UPS that required an oddball RS-232 serial cable before it
> > would communicate. There were different variants available and only one
> > would work. Posting details of the brand/model of UPS involved might
> > get better help.
>
> OTOH, if the manufacturer has any common sense, at worst they'll require
> a "standard" (NOT!) null-modem cable. At best, they'll have
> circuitry/software on-board that accepts either a straight-through or
> null and adapts itself.
>
> Being an _old_ telecom guy from way back, I prefer what was called a
> symmetrical null modem fully configured. From memory (and therefore
> suspect)
>
> Pin---->Pin
> 2 3
> 3 2
> 4 4
> 6 6
> 7 7
> 8 20
> 20 8
>
> Some also do 5 to 5.
>
> However, a 2-3 cross and DTR and DCD high is all that really is needed.
>
> Google for RS-232 will get you a ton of stuff.
>
> As to the OP original question, check BIOS settings and make sure your
> serial is enabled. Set it to COM 3 and IRQ 4 should work. This would
> equate to "0" in an *IX system.
>
Yes, it says
COM Port 1 3F8/IRQ4
It's a long time since I did anything with com ports, and I wasn't expert,
then, but that looks right.
> Look in your /var/log/messages file. At boot, you should see the device
> recognized.
>
Feb 26 12:12:25 borg2 kernel: serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a
16550A
Feb 26 12:12:25 borg2 kernel: serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a
16550A
Feb 26 12:12:25 borg2 kernel: 00:05: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
Is this what I'm looking for? I don't see anything else.
> Also, Minicom is _easy_ to use and understand. Give it a try. Even the
> man pages are not difficult.
>
Easy when you know how, eh? :-) I did try it. I changed it to
monitor /dev/ttyS0. Apart from that, I hadn't a clue what to do. I did look
at the man page, too, but not knowing what I was looking for didn't help.
Anne
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