Chapter goals

Read only memory

• ROM – random access memory device that can store data permanently or semi-permanently
• Typically used to store BIOS (basic input output services)
• Instructions stored in ROM is called firmware

Memory packaging

CPU Memory Access

• Management of RAM is critical to performance of computer
• Organization, access, and management or RAM is done by the operating system
• How memory is accessed is large factor in performance of RAM

Physical memory organization

• Main memory of any computer is a sequence of contiguous memory cells
• Addressable memory – highest number storage byte that can be represented
• Determined by the number of bits used to represent an address
• If 32 bits used to represent and address, highest address is 232 = 4,294,967,296, or 4 GB
• Physical memory – actual memory installed, usually less than addressable memory