2 INTERMEDIATE AGE OPEN CLUSTERS - NGC-752 AND NGC-3680

In this paper, with the aid of synthetic color-magnitude diagram (CMD) technique we study two scarcely populated and slightly metal-poor int ermediate age open clusters, namely NGC 752 and NGC 3680. The analysis is made using both standard and overshoot models calculated by the Pa dova group (Fagotto 1990; Alongi et al. 1991, 1993). The advantage wit h the synthetic CMD technique is that it allows for quantitative predi ctions for the star counts and luminosity functions. Adopting the meta llicity indicated for each cluster by current determinations, we seek to determine the color excess, distance modulus, and age at the same t ime. Looking at the fit of the whole CMD, the behaviour of the main se quence stars LF, and two suitable ratios of star counts we try to disc riminate between the two evolutionary schemes. We suggest that models with convective overshoot ought to be preferred to the classical ones.