With the HiSCORE (Hundred*i Square kilometer Cosmic ORigin Explorer) experiment we aim at the exploration of the accelerator sky using indirect air shower observations of cosmic rays from 100 TeV to 1 EeV and gamma rays above 10 TeV to several PeV. In this paper the HiSCORE detector is discribed and the results of the first prototype deployment are shown. Several components are discussed like the photomultiplier tubes, the clip-sum-trigger and the DRS4 based data acquisition. We present data taken with a first prototype station in April 2012 at Tunka.