I've got several 600 and 600E machines that currently run VL 5.8. I had a few fits with the standard install, since it wants to use ACPI and that seems quite incompatible with the 600/E's. The ACPI interfacing to hardware has evolved a lot, and older hardware often did things differently or had maker-unique features, even if they had *some* version of ACPI.
Try halting the boot menu with 'tab' when you see the choices, then manually enter
'linux noacpi pci=noacpi acpi=off noapic'
This will hopefully let you boot. If so you can put that into an 'append' line in /etc/lilo.conf. You may loose some functionality like suspend/hibernate.
For my machines, I've compiled a custom kernel using Legacy Power Management API, no ACPI. and included some APM (Advanced Power Managment) choices such as 'Use real mode APM BIOS call to power off'. I also included Pentium II in the CPU choice, and a number of other tweeks which stripped out making modules for hardware that can't ever possibly be installed. All this resulted in a kernel that seems at least 25 percent faster.
There's a *LOT* of early postings and web references for early IBM laptops, including www.thinkwiki.org
. Some of these documents tend to be self-contradictory, or applicable to much earlier linux distros, so you'll have to check multiple sources to piece together information. Later linux kernels handle most of the function key combinations, and the various documents may give you additional hints. There's also a thinkpad configuration program that lets you do things like vary the way the trackpoint device works.
Also, be sure you have the latest BIOS update for your machine. Those are available on the lenovo thinkpad support site. Again, be SURE you match your model's type number version with whatever you download.