VIS Readout Electronics (top) and Power Supply Unit (bottom). The Readout Electronics consists of two double-sided circuit boards containing the 12 analogue channels – three repeating analogue circuits can be seen in the topmost board – with the digital board containing the Field Programmable Gate Array between them and to the rear of the unit. The connectors to the upper flexible connections from the CCDs are at the front of the unit. The Power Supply Unit contains also a tightly populated double-sided circuit board. The planar transformers can be seen on the centre-left of the unit.