On Thursday 26 February 2009 18:55:22 William L. Maltby wrote: > On Thu, 2009-02-26 at 16:55 +0000, Anne Wilson wrote: > > On Thursday 26 February 2009 13:37, William L. Maltby wrote: > > <snip> > > > > > > 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 > > > > > > Didn't you say there was only one port? There might be a second on the > > > main board that is accessible via a header. If it's not hooked up > > > disable all but the first in the BIOS (later). It's not really hurting > > > anything as is, but it will free the I/O address and IRQ for assignment > > > to other devices. > > > > I believe you are right. I remember those - and the 25-9-pin adapter :-). > > Peering around the back in a dark corner, I could well have been > > mistaken. OK - female socket, so that's a COM port, I think. > > To be politically correct and eliminate ambiguity, we'll change the > terms here. Socket (formerly female connector) on the computer s/b a > parallel printer port. Almost always a 25 pin in the past, but I've not > kept up with that stuff over the years. > > Plug (formerly male connector) on the computer s/b serial ports. > > On the cable, this is reversed, of course. Now if the cable has RS-232 > on both ends and is not a fully symmetrical null modem cable, it will > make a difference which end is connected to what. Make sure your cable > socket end is what's hooked to the computer. Often the cables will be > labeled which end goes to computer or device. > > Sometimes cables have the same gender on both ends. If they've done that > you could just have the cable reversed (presuming it's one of the > asymmetric cables). It's not uncommon for a null to be made by jumpering > certain pins on just one side of the cable and crossing 2 and 3 end to > end. > > > Now I'm really confused. The BIOS definitely only shows one COM port. > > To be > > Ouch! Since I've not kept up with this stuff I can't sat if there are > other new devices which use 16550 serial drivers. _But_, there are > definitely 2 ports as the detection routines must write to the ports and > read status to determine if it's a 16450, 16550 and revision A or not > (the original 16550 had insufficient buffer IIRC and the A had to be > issued to prevent overflow at higher speeds. CPUs "back in the day" were > just to slow to handle the interrupts quickly enough). > > My guess is that your BIOS has a "menu" in the legacy devices area that > has a drop-down or scrollable menu to select which port to configure. In > there you can enable/disable, change default I/O and IRQ settings, etc. > I think you'll find a second port defined. > OK - so far I've had to do this in short spells, which is definitely not the most productive. Hopefully tomorrow I'll get a good long spell when I can check out manuals both for the motherboard and the UPS. > Which raises the possibility of the computer's connector being on ttyS1 > instead of 0. I can change the config files and try those, too. > But I suspect if you check the back of the computer you > might see two plug connectors. These should be the serial ports. In > today's world, probably 9 pin. > > > honest, I can't remember whether I connected it or not. I guess I ought > > to open the box and see what's what, but not today - it's already too > > late to do that. > > Where's your dedication?! Where's your glass of wine?! Not at the same > location?! Time to leave I guess! :-) > Oddly enough my husband can get quite tetchy if I spend more than 12 hours a day with a computer :-) > > > > 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. > > > > > > Yes. That means that all is as expected (i.e. as _I_ expect). > > > > > Ctrl-A Z - yes, I found that. > > In one of the menus from there, IIRC, you can set baud rate, parity, > flow control, etc. BTW, someone mentioned UPS. Really dumb ones don't > send anything except a power loss or battery low indication. Old ones > used to do this just be controlling DTR (IIRC) and you couldn't "see" > anything until it was raised. I don't know the details of yours (if it > is a UPS) but there should be some docs or a CD that describes a minimal > amount of that information. Or maybe they expect WinBlows and just put > that information in a help menu. > In the 'User Manual' that comes with it there is no such info, as far as I can see. There's a 120-page manual on the CD. I'll examine that tomorrow. However, at a glance, it seems to expect you to set things up with its own gui software. Since there is a Linux setup section, I'm guessing that it runs in a browser. Again, I'll give it my attention in the morning. > BTW, someone mentioned RS-232C. That's the cable and electrical > specifications. RS-232D is the connector specifications for a "D" shell > connector. They don _not_ conflict. They are just different parts of the > same overall specification. So you need have no confusion if you see us > reference the seemingly conflicting specifications. > Being only moderately geeky, I just think of RS-232 as serial connection - I don't know the details :-) > > Settings at present: > > > > A Serial Device : /dev/ttyS0 > > B Lockfile Location : /var/lock > > C Callin Program : > > D Callout Program : > > E Bps/Par/Bits : 38400 8N1 > > F Hardware Flow Control : Yes > > G Software Flow Control : No > > Hardware flow control is suspect _if_ the device doesn't allow flow > until some event is seen, e.g. DTR or DCD and/or some information from > the device is ready to be transmitted. This could make it look like > nothing is working. But that really depends on how the device is > supposed to behave. > > Unless the device can send large amounts of data or requires flow > control, you might try disabling it. > OK - I'll look at that, too. I'm not often beaten by things, but sometimes I have to fight them on and off for quite a while before they are resolved. I'm grateful for all the help I'm getting here. I shan't be giving up for a good while yet :-) if at all. Anne -- New to KDE4? - get help from http://userbase.kde.org Just found a cool new feature? Add it to UserBase -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 197 bytes Desc: This is a digitally signed message part. URL: <http://lists.centos.org/pipermail/centos/attachments/20090226/9db8495a/attachment-0005.sig>