No Memory abstraction Early mainframe, early minicomputers, early personal computers had no memory abstraction 口 MOV REG|STER1.1000 a Here 1000 means move the content of physical memory address 1000 to register Impossible to have two programs in memoryNo Memory Abstraction ◼ Early mainframe, early minicomputers, early personal computers had no memory abstraction… ❑ MOV REGISTER1, 1000 ❑ Here 1000 means move the content of physical memory address1000 to register ◼ Impossible to have two programs in memory