how do iI assume "st8" means "straight". That means you are probably starting off wrong. My guess is that you have a Windows machine with a rewritable CD containing a filesystem already. That puts the .iso file on the CD as an ordinary file, not as a CD image.
First perform a md5sum and check the values is match with the file of the sum file
i download them st8 to the CD
When you try to boot the file, the system looks for a boot loader that it can't find. Normal behavior for a CD made incorrectly.
Download the ISO file to your hard disk and then burn it as an image, not as a file copy. Make sure the system is quiet, because burning the CD requires a fast stream of bytes (which is why you can't safely burn straight from a download session).
Hope this helps. Erik