I'm sorry mate, I wasn't even thinking about the IDE chipset
support/bugfixes category. Who is the manufaturer of your
motherboard? Is this an ASRock motherboard?
Have you already installed Slackware?
If so, does all your hardware work?
Are you recompiling a new kernel? Which one?
The only thing in the 2.4.26 kernel is SiS5513, which
is a discontinued K6 chipset.
You might want to read this link from SiS ->
http://www.sis.com/support/faq/linux.htm
SiS doesn't have a Linux driver for any chipset software
on their site.
I really think you'll be okay with the generic kernel, and if
you recompile, you should be able to keep modules for
anything SiS related in the new kernel.