This rack mounted cage contains many custom circuits of a computer controlled data acquisition system. The plug-in modules on the left are differential input amplifiers, summing amplifiers, integrators and differentiators. The gain and dc offset of these circuits are programmed and stored by the operator using the keypad and rotary encoder on the rightmost panel. The two modules adjacent to this panel are digital outputs. These outputs can be set and cleared via a computer interface or keypad control. Additionally, two module provide gain and offset control to a 12 channel analog preamplifier panel (not picture) wired to a computer analog to digital boards. At power up, all gains and offsets are recovered from nonvolatile memory.