  Nonlinear time-dependent calculations are being carried out in order to study
the evolution of vertically-integrated models of non-selfgravitating, transonic
accretion discs around black holes. In this paper we present results from a new
calculation for a high-alpha model similar to one studied previously by Honma,
Matsumoto and Kato who found evidence for limit-cycle behaviour connected with
thermal instability. Our results are in substantial agreement with theirs but,
in our calculation, the disc material does not always remain completely
optically thick and we include a suitable treatment for this. We followed the
evolution for several cycles and determined the period of the cycle as being
about 780 seconds. Advective cooling is dominant in the region just behind the
outward-moving peak of surface density. The behaviour of this model is
significantly different from what we saw earlier for low-alpha models (which we
discussed in a previous paper) and we contrast and compare the two situations.
