[ale] Serial consoles

[Todd Graham Lewis]

On Mon, 20 Jan 1997, Eric Z. Ayers wrote:

> Now, a PC is unlike many other UNIX workstations/servers in that there
> isn't a command line console burned into firmware.  We have Alpha
> stations with serial console ports attached to a terminal server. 

As do we.  Suns also do this.

I have heard (I think; this was ancient history in computer terms) of
companies selling PCs with serial consoles supported from the BIOS.
Anyone else out there have a URL for this?

> First of all, the serial port is active even when you are down in the
> firmware mode.  This means you can watch the entire boot process from
> the serial port.   This command line console also has some hardware
> diagnostic commands and allows you to boot of of different disks or into
> a different operating system.  Also, there is a special escape sequence
> that breaks out of the operating system into the command line console
> interface.  This is helpful when the machine has crashed or for some
> reason up, but not responding.

Ja, PC hardware does suck by comparison.  (Did you notice that the AXP
boot prompt includes tab completion?  I love those damned boxes.)  Still,
it is useful in that you can talk to and see lilo and everything after
lilo in the boot process, and that's a lot; rarely is your machine so
hosed that lilo won't come up.  When it is that hosed, there's nothing
that Linux or anything else can do on PC hardware.  When it's not, then
serial consoles make a world of difference.

__
Todd Graham Lewis             Linux!                 Core Engineering
Mindspring Enterprises  tlewis at mindspring.com   (800) 719 4664, x2804