In that case you could just use 20 sprites with stars on to cover the screen horizontally. Each sprite is 512 pixels (32 characters) high and they wrap around vertically automatically so there will be no gaps. Just move each one up or down vertically (depending on which way you want the starfield to scroll) You could then have a second or even third set of sprites all moving vertically at different speeds to create a parallax effect. No need for any scrolling libraries at all
