1. Expansion Buses
Engr.Shakeel A.Laghari

2. A PC needs additional components, though, for interacting with human users and other computers.
Graphics components
on-board graphics
expansion slot
the video components in a PC process some of the complex graphics data going to the screen, taking some of the load off your CPU
older AGP, newer PCI standards

3. Ports a place on the outside of your PC where you can plug in a cable.
USB Port 
Ethernet port 
FireWire
Video ports & audio ports
Legacy ports

4. Peripherals
Any piece of hardware that is not mounted inside a PC's case.
basic input and output devices: monitors, keyboards and mice
Anything you can plug in to a port on the PC is one of the PC's peripherals

5. Expansion slots
To add components to a PC that don't have a designated slot somewhere on the motherboard.
Removable components designed to fit into expansion slots are called cards
Add extra video cards, network cards, printer ports, TV receivers and many other custom additions
card must match the expansion slot type,

6. Powering Up a PC boot process, or booting the PC
to start something from the very beginning
The boot process is controlled by the PC's basic input-output system (BIOS)
Besides controlling the boot process, the BIOS provides a basic configuration interface for the PC's hardware components.

7. boot process in a PC power button
The PC performs a power-on self-test (POST)
The PC displays information on the attached monitor showing details about the boot process
The BIOS attempts to access the first sector of the drive designated as the boot disk
the BIOS confirms there's a bootstrap loader, or boot loader
Once the boot loader is in memory, the BIOS hands over its work to the boot loader
OS is ready for user interaction

8. bus bus is a channel or path between the components in a computer.
There are many different types of buses
lets you connect components to the computer's processor
Hard disks, memory, sound systems, video systems.
makes parts more interchangeable

9. System Bus vs. PCI Bus A typical desktop PC today has two main buses
system bus or local bus
connects the microprocessor (central processing unit) and the system memory
The second one­ is a slower bus for communicating with things like hard disks and sound cards.
PCI bus
These slower buses connect to the system bus through a bridge

10. integrating the data from the other buses to the system bus.
Technically there are other buses as well
Universal Serial Bus (USB)
 Firewire

12. PCI History
The original PC bus in the original IBM PC ( 1982) was 16 bits wide and operated at 4.77 MHz.
known as the ISA bus
9 MBps (megabytes per second)
The ISA bus remained in use even after more advanced technologies were available to replace it.
Long-term compatibility with a large number of hardware manufacturers.
Before the rise of multimedia, few hardware peripherals fully utilized the speed of the newer bus

13. Extended Industry Standard Architecture (EISA)
32 bits at 8 MHz
Vesa Local Bus (VL-Bus).
32 bits wide and operated at the speed of the local bus
The VL-Bus essentially tied directly into the CPU

14. Peripheral Component Interconnect
early 1990s
 Intel introduced a new bus standard, the Peripheral Component Interconnect (PCI) bus. 
It provides direct access to system memory for connected devices, but uses a bridge to connect to the frontside bus and therefore to the CPU
PCI can connect more devices than VL-Bus
PCI originally operated at 33 MHz using a 32-bit-wide path
increasing the speed from 33 MHz to 66 MHz 

15. PCI cards use 47 pins to connect
 which can control the PCI bus without CPU intervention
 it did not achieve popularity until the arrival of Windows 95 (in 1995)

16. Plug and Play
can connect a device or insert a card into your computer and it is automatically recognized and configured to work in your system.
The introduction of PnP accelerated the demand for computers with PCI

17. Adding a PCI Device
PCI-based sound card to your Windows XP computer.

18. plug the sound card into an empty PCI slot on the motherboard
The systemBIOS initiates the PnP BIOS
The PnP BIOS scans the PCI bus for hardware.
The sound card responds by identifying itself. The device ID is sent back across the bus to the BIOS.

19. PCI-Express
developed by Intel (and formerly know as 3GIO or 3rd Generation I/O),
looks to be the "next big thing" in bus technology
PCI-X and PCI-X 2.0,

20. Accelerated Graphics Port

21. Accelerated Graphics Port
Enables your computer to have a dedicated way to communicate with the graphics card, enhancing both the look and speed of your computer's graphics.
AGP is based on the design of the PCI bus; but unlike a bus.
provides a dedicated point-to-point connection from the graphics card to the CPU.
clear path to the CPU and system memory, AGP provides a much faster, more efficient way for your computer to get the information it needs to render complex graphics. 

22. Small Computer System Interface
a fast bus that can connect lots of devices to a computer at the same time
 including hard drives, scanners, CD-ROM/RW drives, printers. 
SCSI uses a controller to send and receive data and power to SCSI-enabled devices
up to 320 megabytes per second (MBps)
lets you put multiple items on one bus. 
It has limited system BIOS support.
There's also no common SCSI software interface.
all the different SCSI types have different speeds, bus widths and connectors, which can be confusing.
 parallel 
Serial Attached SCSI (SAS)
3.0 gigabits per second
 128 devices or expanders.

23. Integrated Drive Electronics (IDE)
personal computers have one or more of the storage devices.
standard way for a storage device to connect to a computer
The original name, AT Attachment (ATA), interface was initially developed for the IBM AT computer.
The basic concept behind IDE is that the hard drive and the controller should be combined.
The controller is a small circuit board with chips that provide guidance as to exactly how the hard drive stores and accesses data. 

24. A ribbon cable from the drive/controller combination ran to an ISA card to connect to the computer
IDE devices use a ribbon cable to connect to each other. Ribbon cables have all of the wires laid flat next to each other instead of bunched or wrapped together in a bundle.
The three connectors are typically different colors and attach to specific items:The blue connector attaches to the motherboard.
The black connector attaches to the primary (master) drive.
The grey connector attaches to the secondary (slave) drive.
A single IDE interface can support two devices
uses a special configuration called master and slave.

25. Parallel Port
Parallel ports were originally developed by IBM as a way to connect a printer to your PC.
When a PC sends data to a printer or other device using a parallel port, it sends 8 bits of data (1 byte) at a time. These 8 bits are transmitted parallel to each other, as opposed to the same eight bits being transmitted serially(all in a single row) through a serial port. 

26. Serial Ports an integral part of most computers for more than 20 years
provide a standard connector and protocol to let you attach devices
modems, to your computer
"serializes" data
Serial ports lower cable costs and make cables smaller
Before each byte of data, a serial port sends a start bit, which is a single bit with a value of 0. After each byte of data, it sends a stop bit to signal that the byte is complete. It may also send a parity bit.

27.  also called communication (COM) ports
the Universal Asynchronous Receiver/Transmitter (UART)
 UART chips have a built-in buffer of anywhere from 16 to 64 kilobytes
Enhanced Serial Port (ESP) and Super Enhanced Serial Port (Super ESP), can reach data transfer rates of 460 Kbps.

28. USB Ports
attach mice, printers and other accessories to your computer quickly and easily.
ives you a single, standardized, easy-to-use way to connect up to 127 devices to a computer.
USB Hubs

29. Ethernet
Why Network?
allows one computer to send information to and receive information from another.
Internetis the most conspicuous example of computer networking, linking millions of computers around the world, but smaller networks play a role in information access on a daily basis.

30. Local area network (LAN) technologies connect many devices that are relatively close to each other, usually in the same building.
Wide area network (WAN) technologies connect a smaller number of devices that can be many kilometers apart
In comparison to WANs, LANs are faster and more reliable

31. Ethernet Interfaces History
In 1980, Xerox, Digital Equipment Corporation (DEC, now Compaq), and Intel published a specification for an “Ethernet” LAN (local area network)
Now exists as a standard - IEEE 802.3
Physical interface uses either coax cable with BNC connectors or twisted pair cable with RJ-45 connectors (10Base-T)
Fast Ethernet
Specified in IEEE 802.3u (100Base-TX)

32. the original Ethernet described communication over a single cable shared by all devices on the network
Data Rate
10 Mbits/s for Ethernet (10Base-T)
100 Mbits/s for Fast Ethernet (100Base-TX)
Configuration
Serial, multi-point (token ring or token bus)

33. Token Bus

34. Token Ring

35. Ethernet Adapter Example - PCI
Addtron
AEF-360TX
RJ-45 connector
BNC connector
PCI bus interface