XIR
The XIR element stands for Resistor array and is actually more of a electrical low level building block for an analog computer. It has a number of inputs with different weights which are translated to currents at the summing junction. This way, you can extend Integrators, Summers or Inverters with more inputs. To do so, just connect the summing junctions of the respective elements.
The resistor between "SJ" and "1" is 1 MOhm, and the resistor between "SJ" and "10" is 100 kOhm.
The picture to the right is from an older version of THAT. The current THAT version doesn't have a 0.1 input. However if you need a 0.1 input, you can connect your input signal via a 10 MOhm resistor to the SJ input, or alternatively via a 9 MOhm resistor to a "1" input.
The cable from SJ of the XIR block to SJ of the integrator, summer or inverter may receive interference from other cables. Try to make this cable as short as possible, and away from other cables. If this doesn't help, you can slow down the integrator, summer or inverter by connecting a 100pF capacitor between the output and SJ input.
Examples
