Now the next question:
I have a 640x480 screen (let's keep it simple: 256 colors). Can I make the backbuffer bigger, let's see 680,520? Then it would look like this:
| _______ |
| | | |
| |_____| |
The big rectangle is the backbuffer and the little one is the screen. Can you use blit to copy only the part that's in the screen to the primary surface?