Haven't used this card but if you've got something where a vendor is giving documentation about Linux you're ahead of the game.
Looking at their site I found:
http://www.highpoint-tech.com/USA/bios_rr1520.htm
This has the drivers bundle which is a tar.gz.
You'd have to download the file from there to your Linux partition.
The you can run:
tar tvzf RR152x-Fedora-2.1.6-1111.tgz
To see what is in the bundle.
You can then run:
tar xvzf RR152x-Fedora-2.1.6-1111.tgz
To extract what is in the bundle.
That should give you the following files.
Install_Fedora_RR152x.pdf
Readme.txt
rr152x-fedora-1-i386.img
rr152x-fedora-2.img
rr152x-fedora-3.img
rr152x-fedora-4.img
rr152x-fedora-5.img
rr152x-fedora-6.img
The pdf is a document you can read with Adobe Acrobat.
The Readme.txt is flat ascii you can read with cat, more, or vi. It tells you the .img files are for specific versions of Fedora (1 through 6).
These are floppy images - to copy out to floppy you should just need to run:
dd if=<file>.img of=/dev/fd0 bs=1440k
Where "<file>.img" is the one appropriate for you distro (e.g. rr152x-fedora-5.img for Fedora Core 5).