1. Peripherals on or near an edge or constituting an outer boundary; the outer area; "Russia's peripheral provinces"; "peripheral suburbs" (computer science) electronic equipment connected by cable to the CPU of a computer; "disk drives and printers are important peripherals"

2. What isn’t a peripheral ProcessorMain Memory System Bus The Central Processing Unit Everything else is a peripheral …..

3. What is a peripheral ? Secondary Storage Keyboard VDU Disk Drive USB devices Printer Speakers CD-ROM Graphics Card Sound Card Power Supply Hard Disk Scanner

4. Input/Output Controllers Connect the CPU to Peripherals Processor Main Memory or “Immediate Address Store” Keyboard input controller Disc input/output controller Keyboard Input DeviceDisc I/O Device

5. Why have this arrangement? Peripheral devices cannot be connected directly to the processor because ….. If they did, new types of peripheral would require a redesign of the processor … or …. Every processor would have to be designed with a slot for every possible peripheral

6. I/O Ports I/O Controller 0101001110 CPU reads and writes to the I/O ports (registers) Peripheral writes and reads to the same I/O ports (registers) Data, Command and Status Registers 11010