The architecture and machine language of this processor are a simplified version of a typical actual processor. Many microprocessors have instruction sets that are very similar to the one in appendix C, except that each instruction would have several variations on how memory could be addressed, and there would be more special purpose registers. The Appendix C machine is a very good, simple machine to use for learning some basics of machine language programming. Later, we will use a progam that simulates the Appendix C machine to run machine language programs. The discussion of machine instructions begins on p 82.
Machine instructions are the actual instructions that a CPU can perform .
Later we will see how these instructions are used to create easier ways for people to program computers. But first, we have to understand how machine instructions work. It transfers data from the operand part of the instruction into a register. It transfers data from a register to main memory. All 4 of these instructions copy one byte of data from one place to another .