Apparatus for correcting and adding data to that taken from a mechanical data carrier

In a numerical machine tool control system comprising:

• a. a program buffer storage memory;
• b. means coupled to the input of said program buffer storage memory for reading control information in the form of records of data each containing an address and an instruction from a mechanical data carrier such as a perforated tape into said buffer storage memory;
• c. a numerical logic control having its output coupled to control the machine tool;
• and
• d. means for sequentially calling up the information in said buffer storage memory record by record in the order of addresses associated therewith and providing said records to said numerical logic control, the improvement comprising apparatus for correcting and supplementing information contained on the mechanical data carrier comprising:
• e. a supplementary storage memory;
• f. means coupled to the input of said supplementary storage memory to enter information in the form of additional records, having addresses the same as at least some of the records entered into said buffer storage memory, into said supplementary storage memory;
• g. means for inserting information interposed between said numerical logic control and said buffer storage memory, said means also having an input from said supplementary memory, for selectively providing to said numerical logic control one of its inputs;
• and
• h. means coupled to control said means for inserting information including means to compare the address of the information being called up from said buffer storage memory for output to said numerical logic control with the addresses stored in said supplementary storage memory and upon finding the same address in said supplementary storage memory to enable said means for inserting information to provide the information stored in said supplementary storage memory to said numerical logic control and otherwise to provide the output of said buffer storage memory to said numerical logic control.