Actually, many of the B variants have an FMS. If I remember right, it's the UNS-1M, as well as the same model CDU. This is almost always coupled with a Collins MFD in almost any Saab 340B cockpit I've ridden in. A similar setup is used on EMB-120's. The very old B's (first of the B models) had a UNS-1M which was actually a NMS (Navigation Management System), the later ones were fitted with a UNS-1K, later again were the UNS-1K+ and the very latest B+ aircraft are fitted with the UNS-1Lw. The B+ has a larger or extended wing and can be recognised by black rather than silver prop hub which is a Hamilton prop instead of the original Dowty Rotol silver spinner props. The only downside of the black prop spinner is that you cannot check if your landing lights are working by day as there is no reflection ;D