What makes the computer a universal CA?
In dictionaries you can find something like the following definition: Computer - the universal automatic processing of digital information, which features software control principle and the principle of in-memory program. The obvious difference from any other computer is in the universality of the CA, under which, according to the theory of algorithms, it should be understood to interpret the work of any machine, i.e., to implement an arbitrary algorithm.
How is universal?
We summarize the known.
1. The device should allow a description of their work in the language of the Turing machine. This requirement meets any CA, including a rigid logic, consisting of combinational circuits and circuits with memory. Management functions they can perform a simple device consisting of oscillator cycles.
2. Technical implementation of the principle of the CU program management can solve many problems, which are sufficient to represent a single alphabet. The program of the selected algorithm is located on an external drive and can easily be changed. The necessary changes in the internal state of CA can be reached on the action of alerting signals the memory elements FF. The serial nature of the processing time in many cases leads to the use of memory for storing input and intermediate results.
3. The principle of the program stored in memory to improve performance W speed memory devices. An important role in addressing this problem becomes. Each team in the memory of the program consists of code it produces action, and may contain an address portion that indicates the location of the CU to the right operand in memory. State changes can affect the behavior of CU program counter. Opportunity to force it through the transfer of control commands makes it very convenient to take into account changes in the state of CA in the program. With the transformation of character convenient double operations.