Screen on TV too large

I use Toshiba Satellite 1800-654S with Trident CyberBlade XPA1 card and driv. 5.1.2527.128, RCA TV OUT. When I use my TV set (Philips 29 inch 100 Hz) as a second display (photos), the computer screen and photos are much larger than TV screen and I can’t to make them smaller, so on TV screen can see only a part of computer screen. I can choose different parameters (even 640×480 or 800×600) but the size is the same. How to make the picture smaller?