The FPGA-based Mock spectrometer (named after its designer/builder, the Late Jeff Mock) contains 14 boxes, each of which contains 2 boards handling bandwidths up to 172 MHz each. To date, the Mock spectrometer has only been available for use with the ALFA 7-beam L-band array, for which the 14 boxes are divided into 2 groups of 7 boxes, each of which can be configured as an independent spectrometer. These will support all ALFA observing modes that are available via the WAPPs, with which they can be operated in parallel. As the WAPPs and the Mocks include both spectral-line and pulsar observing modes, this facilitates two-way (or more) commensal observing.
It is intended that the Mock spectrometer will soon be available to operate in ``single-pixel mode'' for use with the observatory's single-pixel receivers.