19. Read Operation
•On a read the CPU will first try to find the data in the
cache, if it is not there the cache will get updated
from the main memory and then return the data to
the CPU.
20. Write Operation
• On a write the CPU will write the information into
the cache and the main memory.
21. VESA - Video Electronics Standards Association
32 bit bus
Found mostly on 486 machines
Relied on the 486 processor to function
People started to switch to the PCI bus
because of this
Otherwise known as VLB
22. ISA - Industry Standard Architecture
Very old technology
Bus speed 8mhz
Speed of 42.4 Mb/s maximum
Very few ISA ports are found in
modern machines.
23. MCA - Micro Channel Bus
IBM’s attempt to compete with the ISA bus
32 bit bus
Automatically configured cards (Like Plug and
Play)
Not compatible with ISA
24. PCI – Peripheral Component Interconnect
Speeds up to 960 Mb/s
Bus speed of 33mhz
16-bit architecture
Developed by Intel in 1993
Synchronous or Asynchronous
PCI popularized Plug and Play
Runs at half of the system bus speed
25. PCI – X
Up to 133 MHz bus speed
64-bit bandwidth
1GB/sec throughput
Backwards compatible with all PCI
Primarily developed for increased I/O
demands of technologies such as Fiber
Channel, Gigabit Ethernet and Ultra3
SCSI.
26. AGP – Accelerated Graphics Port
Essentially a high speed PCI Port
Capable of running at 4 times PCI
bus speed. (133mhz)
Used for High speed 3D graphics
cards
Considered a port not a bus
Only two devices involved
Is not expandable
27. IDE - Integrated Drive Electronics
Tons of other names: ATA,
ATA/ATAPI, EIDE, ATA-2, Fast
ATA, ATA-3, Ultra ATA, Ultra
DMA
Good performance at a cheap
cost
Most widely used interface for
hard disks
28. SCSI - Small Computer System Interface “skuzzy”
Capable of handling
internal/external peripherals
Speed anywhere from 80 – 640
Mb/s
Many types of SCSI
29. Serial Port
Uses DB9 or DB25
connector
Adheres to RS-232c
spec
Capable of speeds up to
115kb/sec
30. USB
1.0
hot plug-and-play
Full speed USB devices signal at 12Mb/s
Low speed devices use a 1.5Mb/s sub
channel.
Up to 127 devices chained together
2.0
data rate of 480 mega bits per second
31. USB On-The-Go
For portable devices.
Limited host capability to communicate with
selected other USB peripherals
A small USB connector to fit the mobile form
factor
32. PS/2 Port
Mini Din Plug with 6 pins
Mouse port and keyboard port
Developed by IBM
33. Parallel port i.e. “printer port”
Old type
Two “new” types
ECP (extended capabilities port)
and EPP (enhanced parallel port)
Ten times faster than old parallel
port
Capable of bi-directional
communication.
34. Game Port
Uses a db15 port
Used for joystick connection to the
computer