jennifers wrote:i am biding on a few computer on ebay. do any of these have opening books?
marauder 6121 fidelity
saitek mephisto talking chess trainer
saitek mephisto junior master
fidelity excellence Voice
novag super sensor IV
novag agate
saitek mephisto
novag constellation 3.6
Regardless of whether they have books or not, I would suggest you steer clear of those cheap, current model Saitek machines on your list (i.e Junior Master and Talking Chess Trainer). They have exceptionally weak programs and in my opinion are not suitable for any player who wants improve.
Of all the machines you have listed there, I would think the Constellation 3.6 is the best bet, although the Excellence Voice is also desirable on account of it's relative rarity. Both these machines (Constellation and Excellence) have - I believe - options to disable thinking on the opponent's time. This is really an essential feature for a weak player who wants to get a good games against a much stronger machine. The main reason I lean towards the Constellation is because you mentioned the opening book. The Constellation series always had excellent, variety-filled opening books and it's inbult randomiser option makes for a huge variety of openings. The Excellence series on the other hand, whilst having reasonably sized books tended to favour a much narrower repertoire given the chance. For this reason I tend to find these Fidelity machines more boring opponents in the long term than the Novag programs.
Also you should be aware that Fidelity machines often don't have the best reputation for reliability. Most collectors here who own ones from the era of the Excellence have had one or more of them opened up on the operating table for surgery of one sort or another.
If you are buying from eBay just try to ascertain that the machine is fully functional before bidding. Another "safer" option might be to purchase something brand new such as the Mephisto Advanced Travel Chess. Although this latter machine is expert rated, it has a large number of options available to weaken it. It is a very reliable and cheap device, as well as being stronger than either the Constellation or Excellence. It also has a nice openings library, with options to make it play aggressive, normal or passive types of openings.
Jonathan
Regards 