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Re: Add on serial port cards and boot prompt.

Hi Nat,

On 6/27/2012 9:28 AM, Nat Sloss wrote:

I am considering upgrading my motherboard (from a Pentium 3 128M memory) and
I've found that only some have on board serial port connectors (for the ones
I've seen you only get one).

If you can visually inspect the board, look for an "unused" 10pin header
(2 rows of 5 pins sticking up out of the board) usually with one of the
corner pins clipped off.  This is often the second serial port (many
motherboards used a "combo" chip that implemented two serial ports
and they just omitted the extra DB9 for cost savings or to economize
on back panel space).  More often than not, these headers used a
common pinout and the DB9-with-attached-10-pin-ribbon-cable is
a pretty common thing to find.

You can often find the connector mounted to one of the filler plates
for the card cage/bus.  I.e., imagine a "card" that consists solely
of a connector with a cable dangling from it.  This facilitates
mounting the connector -- at the cost of a card slot.

So I'm stuck to the possibility of an add on serial board (PCI or PCI-e).

I am currently accessing my computer through a serial console enabled from

I am considering building the system without a video card as I'll mostly use
network and serial access.

So my question is will boot on the i386 or amd 64 support add on serial port
cards?  Will I be able to access the boot menu as before?

I've played musical chairs with my machines so often that I can't
swear to the fact that my name server is currently configured that
way but it was, at one point.  I think I might have a 7" monitor
attached to it, currently (it's all tucked away under a dresser else
I would go check to be sure :< )

You'll have to build a custom kernel:

options CONSDEVNAME="\"com\"",CONADDR=0x???,CONSPEED=?????

Note that you can also replace the bootstrap code to talk to the
serial port "earlier" in IPL.

I've heard of some cards having a legacy mode does this mean that it will be
on port 0x3F8?

I'm hoping that someone on the mailing list has tried this.

Thanks in advance,

Good luck!

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