What is assembly language?
The CPU (central processing unit) or microprocessor acts as an interpreter. It reads instructions one at a time from memory and performs each action. These instructions are in what is called machine language. The instructions are just bytes of binary data. Machine language instructions, which may have data associated with them, may be one byte long; most are two or three bytes long, and some are larger. For example, there is an instruction which instructs the processor to clear the carry flag. (Don’t worry about what this means.) This particular instruction has a one-byte machine language code: “11111000b” (F8 hex). Whenever the processor reads in the instruction F8 hex, it will clear the carry flag. Multi-byte instructions often include data. These data are usually called operands. These are usually extra bytes added after a instruction code; the instruction codes themselves are called opcodes. The extra bytes might hold a value representing a certain register, or an address, or some
