If BIOS uses the same drivers for SATA and PATA devices, why can't LINUX LiveCD's and other software do likewise?

I'm starting a new thread for this topic, even though it's really a
follow-on from an earlier thread I initiated here,
https://groups.google.com/forum/hl=...romgroups#!topic/comp.os.linux.setup/8e6qzvQKdv8 .

The earlier thread was prompted by my oldest computer being unable to read
Linux LiveCD's and LiveDVD's despite it being able to read all sorts of CD's and
DVD's with either Windows or Linux booted up. That problem was traced to a quirk
in Linux Live media which makes it impossible to boot when placed in older,
PATA-based drives.

I had suspected a problem like that at the outset, but I dismissed it because it
seemed inconsistent with another computer of mine having no problems booting
Live media ever after I transitioned them from PATA- to SATA-based drives. You
see, if SATA and PATA drives are completely different, then wouldn't I have had
to change the BIOS when I upgraded from PATA- to SATA-based drives? After all,
the BIOS has to have at least a rudimentary driver capability in order for it to
detect and start devices with boot-up capabilities, no? Well, I didn't have to
upgrade the BIOS, despite the PATA-to-SATA upgrade, which begs the question
that's the subject of this thread: If a BIOS can use the same software driver for PATA- and SATA-based media, then why can'd Linux LiveCD or LiveDVD media be
designed to do likewise?

Jeff