The TOSCA device was built to investigate non-circular plasma cross-sections, minor radius compression and limiting values of beta. A wide range of investigations on minor radius and minor/major radius compression have been conducted which show improved confinement on detachment from the limiter. The shaping studies have explored elliptic, D-shaped and triangular plasmas. Detailed comparisons between theory and experiment for positional instabilities in a variety of shapes have been made. The investigations also demonstrated the failure of shaping to significantly decrease the MHD activity on a tokamak. Investigations of limiting beta both ohmically and using powerful electron cyclotron resonant heating have shown that the critical beta is proportional to the plasma current and reaches values very close to the predicted theoretical limits. A variety of studies on MHD instabilities have been made and attempts to control them using small resonant helical fields. Basic investigations of the influence of fluctuations on confinement have been made by a variety of techniques.