In this paper the architecture of the MIX system is described. It was designed to investigate some of the factors involved in applying reconfigurable and/or fixed logic in a typical engineering algorithm. A matrix-vector multiplier of 32 bit floating point numbers, is used as a vehicle for the investigation. The results indicate that fixed logic is more suited for floating point units and memories white reconfigurable logic is useful for implementing control logic providing significant flexibility. It is also found that the additional de(av in reconfigurable logic can very effectively overlap with the operating time of the fixed logic subsystems. The advantage of reconfigurability of the control is therefore combined with the high bandwidth properties of the fixed logic.