How do I change NDSL Wallpaper with R4 Revolution

New to NDSL and this forum..so HI!
Got a NDSL with R4 Revolution and 1Gb SD
The "operating system" is d/l onto the SD card as well as the games .... which directory or patr of the o/s do I need to reprogram in oreder to be able to change the one screen saver I have (of pac man) into a Spiderman opening screen?
Also I believe there are 12 themes which you can cycle thro (select then A after you switch on)..how do I d/l these etc
Also I have 2 NDSLs...one has the above set up, the other does have 12 themes which you can cycle through....I can't fathom the file directories/files etc to be able to see where the differences are in order to fiddle around..Can you help

Many many thanks
Ostin

well, if you'd read the documentation at all that came with your R4 you'd find:

inside the _system_ folder are a bunch of theme folders (theme1, theme2, etc etc theme12)

add a skin to each with the default naming convention, and you're gtg

using select you can toggle thru the 12, or leave it on auto, and it'll change for you each month


from the R4 webpage http://www.r4ds.com/product-en.htm#a3

Quote:

---

7) Switch of the Skins

If the skin does not exist in the directory of _system_ in TF/microSD, it automatically uses the Skin from formal Beta Edition;

There are 4 pictures at the directory "system/_system": logo.bmp ? icons.bmp ? bckgrd_1.bm and bckgrd_2.bmp. They are the background of the R4 operation interface; they can be changed to fit your style.

logo.bmp - Background of the Top Screen of R 4' s startup.
icons.bmp -- Background of the Bottom Screen of R 4' s Startup.
bckgrd_1.bmp -- Background of the Top Screen of R 4' s Explorer.
bckgrd_2.bmp -- Background of the Bottom Screen of R 4' s Explorer.

Note:
Do not change the picture's name;
Make sure the picture is .bmp format, 8-bit/24-bit;
Make sure the picture is 253*192 pixels.

After finishing process on the pictures, copy the "_system" folder to the root directory of the CF card.

If the Skin exists in the directory of _system_ in TF/microSD, it automatically enters multi Skins mode.

The Skins in multi Skins mode can be switched manually and automatically, it is automatically switched with the Skins by months.

The method of the Skin switch is: Click "SELECT" key in main menu, it switches between twelve manual modes and one auto mode, the chart is showed as below (It automatically skips if the Skin does not exist in the directory of themes):

If the users would like the switches of multi Skins while playing, they only need create the directory of themes in the directory of _system_.

---

i got a problem.after i downloaded a themes and paste it to my themes[theme01..etc]folder.then i start up my NDS.my NDS bottom screen and top screen become purple colour..and the icons cant been seen..then i close my NDS and open it again..same problem..wat should i do..?

million of thanks =)

Daniel