I got this from Dugen Chen's website ----> http://duganchen.ca/writings/slackware/setup/
"Setting the Console Video Mode
If you’re lucky, your video card might support a VESA video mode in your monitor’s native resolution. That will allow you to use a framebuffer in that resolution.
Go to SlackBuilds.org and install hwinfo. Then enter the following as root:
It will print out a list of VESA video modes that you can set your Linux console to. For example:
Mode 0x0361: 1280x800 (+5120), 24 bits
The important parts are self explanatory: the mode number, which starts with 0x, the width and height, and the number of colors.
If I have a 1280×800 monitor and I like the mode above, I would edit lilo.conf and change the vga setting to 0×0361.
If you don’t see a mode appropriate for your monitor, then just set vga=normal. It’s faster."
Maybe if you use the hex code in lilo it will work?