Create your own SMS CD Image
Use this if the CD image is out of date, or if you want to put some media onto a CD along with SMS
1. You will need to find and download CDGenPS2 v3.0
2. Download the latest SMS Release, and the latest uLaunchELF release. you will need to sign up at the forums to view the uLaunchELF pages.
3. Unzip the uLaunchELF zip file, and delete everything but BOOTc.ELF. (you don't need the other stuff)
4a. Rename "BOOTc.ELF" to "BOOT.ELF".
4b. Rename "SMS Version x.y (Rev x).elf" to "SMS.ELF"

If you don't want to include uLaunchELF on the CD, just rename SMS.ELF to
BOOT.ELF instead.
5. open Notepad, and paste this:
BOOT2 = cdrom0:\BOOT.ELF;1 VER = 1.00 VMODE = NTSC
Note: Use PAL instead of NTSC if you have a PAL TV, and make sure to add
a blank line after the last line (press enter after NTSC)
6. File --> Save As: "system.cnf" (make sure it is a CNF file, not a TXT file)
You should now have:

7. Open CDGenPS2, and in order:
7a. Drag system.cnf into the main window.
7b. Drag BOOT.ELF into the main window.
7c. Drag SMS.ELF into the main window.
(don't rush, do them one at a time).
8. right click system.cnf -> edit.
9. choose Fix LBA, and enter '12231':

10. Go ahead and add some other files and folders now if you want, such as MP3's and videos... you might as well use the rest of the space on the CD.
11. CDGenPS2 should look like this...

12. Choose File -> Create CD. Save the file as type BIN files. (the name doesn't matter, so long as you remember where you saved it)
13. Burn the image