Assembly language
	High-level language
		a = b + c;
	Machine language
		000000	01000	01001	01010	00000	100001
	Assembly language is between high-level and machine
		Each statement defines one machine operation
		Directly represents architecture
		Assembler program translates to machine language
	ISA: Instruction Set Architecture
		Machine structure as seen by the programmer
		Each kind of machine has its own ISA
			Sun (Labs): SPARC
			DEC (Class cluster): Alpha
			HP: PA (Precision Architecture)
			IBM Classic: S360/370/390/zSeries
			PC: Intel x86
			MAC: Motorola 680x0