Control system of a numerical control unit

A control system of a numerical control unit for use in controlling a machine tool having a plurality of control switches associated thererwith, said control system comprising:

• a digital memory for storing a control instructions program;
• means for reading out for execution control instructions of said control instructions program, from said digital memory;
• a plurality of memory registers responsive to said means for reading out for storing a plurality of said control instructions;
• a plurality of register groups for storing sets of data for numerical control;
• at least one selector circuit connected between particular memory registers and a particular register group for selectively transferring data to a said particular register group;
• a logic arithmetic operational unit for selectively receiving data from particular portions of said register groups and for carrying out arithmetic operation in accordance with instructions in the memory registers;
• servo mechanism means connected to the output of said logic arithmetic operational circuit and memory registers for controlling said machine tool in accordance with instructions in the memory registers;
• an address register for providing address information to said memory;
• and a selector means responsive to said arithmetic operational unit and being further responsive to the condition of signals and switches in said machine tool for determining in combination with the information stored in a particular one of said memory registers, the address of the control instructions to be next executed.