sentences:  In the 1960s memory was relatively expensive, and CPU designers produced instruction sets that densely encoded instructions and data in order to better utilize this resource.For instance, the codice_1 instruction would be provided in many different forms that would gather A and B from different places; main memory, indexes, or registers.Providing these different instructions allowed the programmer to select the instruction that took up the least possible room in memory, reducing the program's needs and leaving more room for data.