I recently had a failure of my motherboard and cpu and was able to replace it with a similar but different vendor (socket 478) motherboard.
My Linux installation, did a filesystem check on the root partition, rebooted, checked the filesystems of the other partitions and after a few logins and a timeout (not clear why it didn't accepted the first login), I could run it as if almost nothing had happened.
Compare this to how I had to "repair" my windowsXP installation!

Is this typical for Slackware(12), all Linux versions, or all Unices?

Good stuff!
Don't know about other *nixes, but certainly all Linux distributions would be similar.
Of course if you had compiled your own kernel and then replaced the cpu with one that was not compatible, it wouldn't haven been quiet as smooth.
Similarly if you had compiled your own kernel and had removed drivers (e.g. using make menuconfig) that you didn't need on the old motherboard, you might have had problems if the same drivers was then needed by the new one.
On my Gentoo box I probably would have had more problems since I have customised it to my cpu and removed plenty of drivers I don't need at the moment. Of course if I was worried I could keep a generic kernel available in /boot to my Grub config.
Linux is maybe the most portable OS there is. E.g. which other OS can run on anything from your watch, phone and TV to giant super computers?

As long as the drivers (loaded into the kernel, on boot) are generic enough to support the hardware you're using, or you have more drivers loaded that you need, everything is kosher.

Well, WindowsXP is one generic kernel. You can install XP (e.g.) on any i386 processor and motherboard as well. The problem arises when you change motherboard even when you need to load a new sata driver as the only new driver; Windows goes in repair mode and installs everything over your current installation. There is more than the driver issue, Windows manages to complicate things because of commercial issues is my guess, it is not a professional but a commercial OS with all sorts of hidden dependencies. That I think is the point. Linux just behaves as an OS should, nothing special about that.

One of the problems I think that causes windows problems in such a situation is the binary and very detailed registry. It contains lots of details on your current hardware and can't handle sudden changes like this (even though, far as I know windows also add lots of unnecessary drivers at installation). Linux is much more flexible in the way it works with the largely text mode /etc tree and the kernel based drivers.

Hi,
WinXP is one build then adapted to suit the hardware. The overlay is the problem with WinXP for a change in hardware that was not original to the install. The exceptions and setting up the registry will always kill you.

As long as the Linux kernel is x86 compatible then you won't have a problem. The problem will exist if drivers for subsystems are different for the MB. With XP you can usually get around this with the safe mode and modify where needed but not always. I would just let M$ do the work.

As for GNU/Linux/Slackware you will have a problem if you custom the kernel. If the stock is x86 then not a problem. You can always modprobe a device if the mapper and devices are not recognized with udev.

Your existing rules would most likely present a problem for different devices. You could always delete the rules and get a renew at boot.

Indeed this would work for pretty much all distros. Some cases in which this may not be true might be if you upgraded the video card and were running proprietary drivers (although the drivers are unified, if you ran a legacy driver and bought a newer card, you'd need to upgrade the driver). Another case is if you have a custom kernel with only what you need built-in ... then you'd have to reconfigure, recompile, reinstall the kernel.

Stuff like this is the reason that I always keep a copy of the huge kernel image handy. If for some reason I need to change hardware and my custom kernel won't work, then I can fall back on the huge kernel.

Hi,

That's our safe mode! I always have a kernel available for trouble. That way recovery is just a few MB of storage for the spare boot kernel. There's always the rescue but why not have alternate means to recovery.

My rescue recovery cd set is about 8 cds of varied flavors.

95% of winbloze "code" is anti-piracy rubbish that tries to stop you from moving your installation to another computer. Not only does that not work (see all the cracks in any web site) but it fsck anyone who tries to recover their own system.

You can clone a generic Linux installation almost effortlessly. I laid a copy of my primary Slackware desktop system onto a laptop in less than 20 minutes one day when I had to travel.