Scenario for description as it just occurred, the other day:

There was an old machine around, with a harddisk 1.7 GB containing no
system, and not being able to read correct from cdrom, when that hardrive is
connected. So, somehow could not install slack there. Gave it another try to
install slack, by putting that hard-drive into a newer machine. No luck,
that drive somehow could not be handled.

Took another harddisk, 40GB. Installed slack on the newer machine. Observed
some strange behaviour on that machine, due to two cdrom drives which it
contained (hdc and hdd) - after setup has found (or accepted) 'source' and
'target' drives for install and after install method has been selected
('full', 'expert', etc - took 'expert'), setup would insist, that on the
other cdrom drive there should be more stuff to install, even if no cdrom
was inside the drive.

(This happened same way, if source was detected automatically into
/var/log/mount or if source was pre-mounted into /cd and made known to
setup. Boot-CD has been burnt as has been provided for in isolinux/*,
containing slackware/* without kde, kdei, gnome, but with isolinux/* and
kernels/*, so no need for a second cdrom - made already several installs
with that kind of image and cannot remember that screen to show-up in setup,
which asks for continuation of input.)

Disconnected one drive, thus skipping this point by hardware, so, finally,
there is one more slackware-10 installed then. Inserted that 40GB harddisk
into the old machine. But that one would not accept the harddrive with its
full capacity in its BIOS. Trying to boot via lilo on MBR would result in
error message consisting in some garbage out from desert data plains on that
harddisk.

But there had been made 'the' boot floppy as well. Now, boot process would
skip the BIOS and start linux from the right partition, now recognized all
the drive correctly.

Will spend another session for the 1.7GB drive with yet another machine. Or
maybe it will be easier to make a cross-install on the old machine from its
now running 40GB drive back to the 1.7GB drive, when that one is inserted as
second harddisk. I'll see.

continuation...

First had a boot-CD with slackware on it, which was not recognized as
bootable on an 'old' machine (Pentium 120Mhz, LBA for harddrives but 8GHz
limit; something with the switches I set for burning the CR might have been
wrong). Checking against an old W98 boot-CD: this one would have been
bootable.

Had a 40GB drive then, not recognized correctly by the BIOS, so installed
slackware on a different machine, installed LILO to MBR and prepared a
boot-floppy. With the boot-floppy, linux could be launched from the 40GB
drive on the 'old' machine.

(Now story continues Inserted 1.7GB harddrive as second drive in the 'old'
machine. Since the slackware 'setup' utility would have been available only,
when booting from cdrom, this was not available to cross-install from
running linux (on 40GB drive) to 1.7GB drive. So installpkg came in, using
the '-root=' parameter. From diskset 'A', installed the 'aaa*.tgz' first,
then in a loop all the rest.

There was room enough to install A, AP, D, K, L and N series.

After installpkg of all that stuff (leaving 350MB free, so, at least, one
should be able to compile a kernel), a second problem arrived with LILO:
Running LILO from hda3, chroot to newly installed linux on hdb1, call LILO,
now, something went wrong with patching the MBR of hdb, even if some LILO
was installed. It had been set/etc/fstab and /etc/lilo.conf.

Detached the 40GB-drive, attached the 1.7MB, now it needed a parameter to
LILO ("label root=/dev/hda1"), then linux would launch, now LILO could be
called again, to patch the MBR correctly.

Questions remaining, related to linux, finally:
Some problem with 'setup', when two CD drives are available.
Some problem with 'lilo' for a new install on a different drive.
And, why did 'setup' disappear from the running system?

> Some problem with 'lilo' for a new install on a different drive.

(should be avoided extensive self-talk, but...)
This one has a simple solution, applicable after 'man lilo'.