CU Module for Analog Paradigm Model-1 modular computer.
The CU-module (short for "Control Unit") is the heart of the analog computer as it controls the overall operation of the computer. It is possible to control the three modes of operation ("IC" - initial condition, "OP" - operate, and "HLT" - halt) manually or to have the computer perform a computation repeatedly with the OP-time controlled in 20 ms increments as set by the three digit switch on top of the module. Using repetitive operation it is possible to generate standing (often even flickerfree) pictures on an oscilloscope (in the picture on the left, an OP time of 20 ms has been setup).
Pressing the IC switch selects the IC mode: All integrators assume their initial condition, preparing them for a computation which is initiated by pressing the OP/HALT button once. Pressing this button a second time causes the computer to go into HLT mode where the integrators hold their last output value. Depending on the time constants set at the integrators, the time necessary to load their respective initial conditions varies. Using the ICTIME button the IC time can either be set to long (sufficient for integrators set to time constant 1 or 10) or fast (about 10 ms) (for computer setups employing only integrators set to a time constant of 100 or even 1000). By pressing the OVLOAD button the CU is setup to halt the current OP cycle if an overload occurs at any computer element of the computer.
Pressing the SINGLE button once will cause the computer to run through IC mode, followed by one OP cycle (the duration of which is controlled by the dial on top of the module), followed by HLT. Pressing the REPEAT button causes the computer to switch repeatedly into IC and OP mode.
Four output jacks yielding a trigger signal which denotes an OP cycle are available as well as two output jacks where a voltage proportional to the duration of the OP cycle is available. The EXTHALT input makes it possible to halt an OP cycle by external means such as a comparator etc.
Product alternative: HC module.