Please help me with Interface Stuff

According the headers or SDL 1.2 SDL_video.h, the surface should look like this:

struct SDL_Surface {
	Uint32 flags;				/* Read-only */
	SDL_PixelFormat *format;		/* Read-only */
	int w, h;				/* Read-only */
	Uint16 pitch;				/* Read-only */
	void *pixels;				/* Read-write */
	int offset;				/* Private */

	/* Hardware-specific surface info */
	struct private_hwdata *hwdata;

	/* clipping information */
	SDL_Rect clip_rect;			/* Read-only */
	Uint32 unused1;				/* for binary compatibility */

	/* Allow recursive locks */
	Uint32 locked;				/* Private */

	/* info for fast blit mapping to other surfaces */
	struct SDL_BlitMap *map;		/* Private */

	/* format version, bumped at every change to invalidate blit maps */
	unsigned int format_version;		/* Private */

	/* Reference count -- used when freeing surface */
	int refcount;				/* Read-mostly */
}

According that, the first 4 fields should be correct but after that, there are quite some fields missing.