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EC1003 UNIT V
UNIT V
Industry standard architecture (ISA), Peripheral component Interconnect (PCI) Accelerated Graphics port (AGP) Plug-and-Play devices – SCSI concepts USB architecture
Buses
l Buses evolved around data path and speed
l Local bus (system) and expansion bus (ISA)
l Buses carry electrical power, control signals, memory addresses, and data
l On-board ports, connectors, and riser slots
• These are “slots” on the motherboard
• Examples
– ISA – Industry Standard Architecture
– PCI – Personal Component Interconnect
– EISA – Extended ISA
– SIMM – Single Inline Memory Module
– DIMM – Dual Inline Memory Module
– MCA – Micro-Channel Architecture
– AGP – Accelerated Graphics Port
– VESA – Video Electronics Standards Association
– PCMCIA – Personal Computer Memory Card International Association (not just memory!)
|
AGP slot |
|
PCI slot |
|
ISA slot |
Industry Standard Architecture(ISA)
– pronounced “eye-es-eh”
• History
– Originally introduced in the IBM PC (1981) as an 8 bit expansion slot
• Runs at 8.3 MHz with data rate of 7.9 Mbytes/s
– 16-bit version introduced with the IBM PC/AT
• Runs at 15.9 MHz with data rate of 15.9 Mbytes/s (?)
• Sometimes just called the “AT bus”
– Today, all ISA slots are 16 bit
• Configuration
– Parallel, multi-drop
• Used for…
– Just about any peripheral (sound cards, disk drives, etc.)
• PnP ISA
– In 1993, Intel and Microsoft introduced “PnP ISA”, for plug-and-play ISA
– Allows the operating system to configure expansion boards automatically
• Form factor
– Large connector in two segments
– Smaller segment is the 8-bit interface (36 signals)
– Larger segment is for the 16-bit expansion (62 signals)
– 8-bit cards only use the smaller segment
• Advancements
– EISA
• Extended ISA
• Design by nine IBM competitors (AST, Compaq, Epson, HP, NEC, Olivetti, Tandy, WYSE, Zenith)
• Intended to compete with IBM’s MCA
• EISA is hardware compatible with ISA
– MCA
• Micro Channel Architecture
• Introduced by IBM in 1987 as a replacement for the AT/ISA bus
– EISA and MCA have not been successful!
• Configuration is not automated
• ISA bus does not manage system resources, as do USB and PCI bus controllers
• ISA device must request system resources at startup
Peripheral Component Interconnect (PCI)
– Also called “Local Bus”
• History
– Developed by Intel (1993)
– Very successful, widely used
– Much faster than ISA
– Gradually replacing ISA
• Configuration
– Parallel, multi-drop
• Used for…
– Just about any peripheral
– Can support multiple high-performance devices
– Graphics, full-motion video, SCSI, local area networks, etc.
• Specifications
– 64-bit bus capability
– Usually implemented as a 32-bit bus
– Runs at 33 MHz or 66 MHz
– At 33 MHz and a 32-bit bus, data rate is 133 Mbytes/s
• PCI bus
– Currently the standard I/O bus
– Uses an interim interrupt between PCI card and IRQ line to the CPU
• PCI bus controller
– Manages the PCI bus and expansion slots
– Assigns IRQ and I/O addresses to PCI expansion cards
• Use Device Manager to see which IRQ has been assigned to a PCI device
Accelerated Graphics Port (AGP)
For AGP Diagram refer your text Book
• History
– First appeared on Pentium II boards
– Developed just for graphics (especially 3D graphics)
• Configuration
– Parallel, point-to-point (only one AGP port / system)
• Specifications
– Data rates up to 532 Mbytes/s (that’s 4x PCI!)
• The Accelerated Graphics Port (also called Advanced Graphics Port) is a high-speed point-to-point channel for attaching a graphics card to a computer’s motherboard, primarily to assist in the acceleration of 3D computer graphics.
· Some motherboards have been built with multiple independent AGP slots. AGP is currently being phased out in favor of PCI Express.
· Type of video card that has its own processor to boost performance
· Features reduce burden on motherboard CPU, (eg, MPEG decoding, 3-D graphics, dual porting, color space conversion, interpolated scaling, EPA Green PC support, digital output to flat panel display monitors, application support for high-intensity graphics software)
Advantages over PCI
• Texturing: Also called Direct Memory Execute mode, allows textures to be stored in main memory.
• Throughput: Various levels of throughput are offered: 1X is 266 MBps, 2X is 533 MBps; and 4X provides 1.07 GBps.
• Sideband Addressing: Speeds up data transfers by sending command instructions in a separate, parallel channel.
• Pipelining: Enables the graphics card to send several instructions together instead of sending one at a time
Versions of AGP
AGP 1x
• A 32-bit channel operating at 66 MHz resulting in a maximum data rate of 266 megabytes per second (MB/s), doubled from the 133 MB/s transfer rate of PCI bus 33 MHz / 32-bit; 3.3 V signaling.
AGP 2x
• A 32-bit channel operating at 66 MHz double pumped to an effective 133 MHz resulting in a maximum data rate of 533 MB/s; signaling voltages the same as AGP 1x;
AGP 4x
A 32-bit channel operating at 66 MHz quad pumped to an effective 266 MHz resulting in a maximum data rate of 1066 MB/s (1 GB/s); 1.5 V signaling;
AGP 8x
A 32-bit channel operating at 66 MHz, strobing eight times per clock, delivering an effective 533 MHz resulting in a maximum data rate of 2133 MB/s (2 GB/s); 0.8 V signaling.
AGP Pro
AGP Pro is a extention to the standard AGP connector and slot on both sides to provide additional power to an AGP card.
It comes in two flavors, AGP Pro110 provides for 50-110W of power and requires two adjacent PCI slots for cooling. AGP Pro50 provides for 20-50W of power and requires a single adjacent PCI slot for cooling.
• 64 bit AGP: A 64-bit channel. Used in high end professional graphic cards.
Small Computer Systems Interface (SCSI)
– pronounced “scuzzy”
• History
– Developed by Shugart Associates (1981)
– Originally called Shugart Associates Systems Interface (SASI, pronounced “sassi”)
– Scaled down version of IBM’s System 360 Selector Channel
– Became an ANSI standard in 1986
• Used for…
– Disk drives, CD-ROM drives, tape drives, scanners, printers, etc.
• Configuration
– Parallel, daisy chain
– Requires terminator at end of chain
• Versions (data width, data rate)
– SCSI-1, Narrow SCSI (8 bits, 5 MBps)
– SCSI-2 (8, bits 10 MBps)
– SCSI-3 (8, bits, 20 MBps)
– UltraWide SCSI (16 bits, 40 MBps)
– Ultra2 SCSI (8 bits 40 MBps)
– Wide Ultra2 SCSI (16 bits, 80 MBps)
USB
• Connection of the PC to Telephone
– The USB provides a ubiquitous link that can be used across a wide range of PC-to-telephone interconnects.
• Ease of use
• Hot plug
• Port expansion
– The lack of a bi-directional, low-cost, low-to-mid speed peripheral bus has held back the creative proliferation of peripherals such as telephone/fax/modem adapters, answering machines, scanners, PDA’s, keyboards, mice, etc.
• Fast
• Bi-directional
• Isochronous
• low-cost
• dynamically attachable serial interface
• consistent with the requirements of the PC platform of today and tomorrow
Wide range of workloads and applications
– Suitable for device bandwidths ranging from a few kb/s to several Mb/s
– Supports isochronous as well as asynchronous transfer types over the same set of wires
– Supports concurrent operation of many devices (multiple connections)
– Supports up to 127 physical devices
– Supports transfer of multiple data and message streams between the host and devices
– Allows compound devices (i.e., peripherals composed of many functions)
– Lower protocol overhead, resulting in high bus utilization
Universal Serial Bus (USB) is a serial bus standard to interface devices to a host computer. USB was designed to allow many peripherals to be connected using a single standardized interface socket and to improve the plug-and-play capabilities by allowing hot swapping, that is, by allowing devices to be connected and disconnected without rebooting the computer or turning off the device. Other convenient features include providing power to low-consumption devices without the need for an external power supply and allowing many devices to be used without requiring manufacturer specific, individual device drivers to be installed.
USB 1.0
- USB 1.0: Released in January 1996.
Specified data rates of 1.5 Mbit/s (Low-Speed) and 12 Mbit/s (Full-Speed). Did not anticipate or pass-through monitors. Few such devices actually made it to market. - USB 1.1: Released in September 1998.
Fixed problems identified in 1.0, mostly relating to hubs. Earliest revision to be widely adopted.
USB 2.0
- USB 2.0: Released in April 2000.
Added higher maximum speed of 480 Mbit/s (now called Hi-Speed). Further modifications to the USB specification have been done via Engineering Change Notices (ECN). The most important of these ECNs are included into the USB 2.0 specification package available from USB.org:- Mini-B Connector ECN: Released in October 2000.
Specifications for Mini-B plug and receptacle. These should not be confused with Micro-B plug and receptacle. - Errata as of December 2000: Released in December 2000.
- Pull-up/Pull-down Resistors ECN: Released in May 2002.
- Errata as of May 2002: Released in May 2002.
- Interface Associations ECN: Released in May 2003.
New standard descriptor was added that allows multiple interfaces to be associated with a single device function. - Rounded Chamfer ECN: Released in October 2003.
A recommended, compatible change to Mini-B plugs that results in longer lasting connectors. - Unicode ECN: Released in February 2005.
This ECN specifies that strings are encoded using UTF-16LE. USB 2.0 did specify that Unicode is to be used but it did not specify the encoding. - Inter-Chip USB Supplement: Released in March 2006.
- On-The-Go Supplement 1.3: Released in December 2006.
USB On-The-Go makes it possible for two USB devices to communicate with each other without requiring a separate USB host. In practice, one of the USB devices acts as a host for the other device. - Battery Charging Specification 1.0: Released in March 2007.
Adds support for dedicated chargers (power supplies with USB connectors), host chargers (USB hosts that can act as chargers) and the No Dead Battery provision which allows devices to temporarily draw 100 mA current after they have been attached. If a USB device is connected to dedicated charger or host charger, maximum current drawn by the device may be as high as 1.5 A. (Note that this document is not distributed with USB 2.0 specification package.) - Micro-USB Cables and Connectors Specification 1.01: Released in April 2007.
- Link Power Management Addendum ECN: Released in July 2007.
This adds a new power state between enabled and suspended states. Device in this state is not required to reduce its power consumption. However, switching between enabled and sleep states is much faster than switching between enabled and suspended states, which allows devices to sleep while idle. - High-Speed Inter-Chip USB Electrical Specification Revision 1.0: Released in September 2007.
- Mini-B Connector ECN: Released in October 2000.
USB 3.0
On September 18, 2007, Pat Gelsinger demonstrated USB 3.0 at the Intel Developer Forum. USB 3.0 is targeted at ten times the current bitrate, reaching roughly 4.8 Gbit/s (600MB/s) by utilizing two additional high-speed differential pairs for “Superspeed” mode, and with the possibility for optical interconnect.[28][29] The two new differential pairs make the cable about as thick as an ethernet cable and provide full-duplex transfers.[30] The USB 3.0 specification was 90% complete as of August 13, 2008[31] and commercial products are expected to arrive in 2009 or 2010.[32] USB 3.0 is designed to be backwards-compatible with USB 2.0 and USB 1.1 and employs more efficient protocols to conserve power[28] while increasing the maximum power available for connected devices.[30]
Access Time
w Seek Time
n Time required to move the read/write head to the proper track
w Latency Time
n Rotational delay
n Time until head is over correct track
w Times measured in ms
EC1003 UNIT III
UNIT III STORAGE DEVICES 9
The floppy drive – magnetic storage – magnetic recording principles – data and disk organization – floppy drive – hard drive – data organization and hard drive – sector layout – IDE drive standard and features – Hard drive electronics – CD-ROM drive – construction – CDROM electronics – DVD-ROM – DVD media – DVD drive and decoder.
• Medium
• The technology or product type that holds the data
• Access time
• The time to get to the data
• Specified as an average in seconds (e.g., s, ms, µs, ns, etc.)
• Throughput
• The rate of transfer for consecutive bytes of data
• Specified in bytes/s (e.g., Kbytes/s, Mbytes/s)
• Online storage
• Memory that is accessible to programs without human intervention
• Primary storage and secondary storage are “online”
• Primary storage
• Semiconductor technology (e.g., RAM)
• Volatile (contents are loss when powered off)
• Secondary storage
• Magnetic technology (e.g., disk drives)
• Non-volatile (contents are retained in the absence of power)
• Offline storage
• Memory that requires human intervention in order for it to be accessed by a program (e.g., loading a tape)
• Sometimes called “archival storage”
• Direct Access Storage Device (DASD)
• Pronounced “dazz-dee”
• Term coinded by IBM
• Distinguishes disks (disk head moves “directly” to the data) from tapes (see below)
• Sequential access storage devices
• Tape drives
• Tape reel must wind forward or backward to the data
Magnetic storage
• A magnetic substance is coated on a round surface
• The magnetic substance can be polarized in one of two directions with an electromagnet (“writing data”)
• The electromagnet can also sense the direction of magnetic polarization (“reading data”)
• Similar to a read/write head on a tape recorder (except the information is digital rather than analogue)
Floppy drive
• First PC floppy drive could hold only 160K.
• PC/XT came with a 5.25-inch 360K.
• Largest capacity for a 5.25-inch is 1.2MB.
• Do not attempt to format a 360K diskette to 1.2MB—you will have multiple bad sectors, and if you write data to the disk, you run the risk of losing the data.
• Also called “flexible disks” or “diskettes”
• The platter is “floppy”, or flexible (e.g., mylar)
• Most floppy disk drives can hold one diskette (two surfaces)
• The diskette is removable
• Typical rpm: 300, 360
• Capacities: 700 KB to 1.4 MB (& up to 100 MB “zip” disks)
- Organization of tracks and sectors
- Density at which data can be stored
- Intensity of magnetic spots on magnetized plastic surface of the disk
l Cluster
u Smallest logical unit of space allocated to a file
u On a 3½-inch high-density floppy disk, one cluster = one sector (512 bytes)
Potential Problems
- Application points to a different drive
- Unrelated error locked up the system
- System BIO or CMOS setup is not correctly configured
- Disk in drive is not formatted
- Floppy drive is bad
Hard Disk Components
w Disk
n Assembly of disk platters
w Disk Drive
n Electromechanical system
l Spins disk
l Moves read/write heads
Hard Disk Organization
w Disk Controller
n Electronic circuitry
w Organization of data
n Concentric tracks
n Divided into sectors
n Divided into logical partitions
w Formatting
n Divides disk into tracks and sectors
n Excludes defective sectors
n About 15% overhead
l Sector headers
l Error-correction codes
l Intersector gaps
w Primary computer storage device
n Secondary Memory
w Spins, reads and writes one or more fixed disk platters
w Storage medium in desktop and laptop computers
w The term “hard” differentiates high-capacity rigid disks made aluminum or glass from low-capacity floppy disks made of plastic
1) First Microcomputer Hard Disk Seagate introduced the first hard disk for personal computers in 1979. At 5MB, the ST506 held 10 times as much as the RAMAC at a fraction of its size.
• A sealed metal housing.
– Protection against dust particles
• An electrical motor connected to a spindle
– Spends as many as 8 magnetically coated platters
• Today’s platters are coated with an alloy about three millionths of an inch thick
– Several thousand revolutions/minute
How a Hard Disk Drive Works
• Logic board receives commands from the drive’s controller.
– Managed by the operating system and BIOS
– Translates commands into voltage fluctuations
• Forces the head actuator to move read/write heads
– Makes sure the spindle turning the platters is at a constant speed
– Tells the drive head to read or write
– A head actuator pushes and pulls the read/write heads across the surfaces of the platters with critical precision.
– Aligns heads with the tracks
– Read/write heads slide in unison across both the top and bottom surfaces of the platters.
– Write the data coming from the disk controller by aligning the magnetic fields of particles
– Read the data by detecting the polarities of particles that have already been aligned
How Disk Space is Organized
When a disk is manufactured,
• Its surface is on a large area.
• An organizational structure must be imposed that uniquely names each physical location on the disk
– Drive controller can specify the exact physical spot where a given bit of data should be written or retrieved
– Cylinders, Heads, Sectors , and Tracks
• CHS
• Each side or surface of one hard drive platter is called a head.
– The number of heads in the same as the number of disk platter surfaces available for writing data
– Almost all magnetic disks are double-sided
– There is a separated read/write head for each side.
– The numbering starts at the bottom side of the bottom platter with 0.
– An average number of heads for a hard disk today is 16
• A track is a combination of the cylinder and head location over the writeable portion of the hard disk.
– In a multiplatter or multiside disk, each side has its own separate tracks
• A 1.44MB floppy disk has 40 tracks per side
• A large hard disk can have tens of thousands
• A sector is the smallest unit that can be read from or written to a disk.
– Pie slices made by lines that cross over the track lines.
– Each sector holds exactly 512 bytes of data
– Modern 1.44MB floppy disks use 36 sectors/track
– A typical IDE hard drive usually has 63 sectors/track
– A SCSI hard drive can have 600 or more sectors per track
• Cylinders are the concentric writeable tracks found on the surface of the platters that make up the hard drive.
– The stack of tracks accessible at a given position constitutes a cylinder.
– The number of cylinders a drive has in the same as the number of tracks on a single disk side
– All areas of a disk at a certain in/out head position on all disk sides combined
– Platter
• A round surface – the disk – containing a magnetic coating
– Track
• A circle on the disk surface on which data are contained
– Head
• A transducer attached to an arm for writing/reading data to/from the disk surface
– Head assembly
• A mechanical unit holding the heads and arms
• All the head/arm units move together, via the head assembly
– Cylinder
• A set of tracks simultaneously accessible from the heads on the head assembly
Calculating the capacity of the drive
Cylinders x heads x sectors/track x 512 bytes/sector
Divide by
– 1024 = KB
– 1048576 = MB
– 1073741824 = GB (Typical size)
Three possible settings in most BIOS Setup programs (translations)
- CHS (Cylinder, Head and Sector) Mode or Normal Mode
- Extended CHS Mode (ECHS) or Large Mode
- Logical Block Addressing (LBA)
Types of Hard Disks
IDE: Integrated Drive Electronics (IDE) is the least expensive way to connect a hard drive to a computer IDE can support two hard drives. Each drive cannot have a storage capacity of more than 528 MB
EIDE: Most new computers come with Enchanced IDE (EIDE). EIDE is faster and can connect more devices to a computer than IDE. EIDE can support up to four devices. These devices can be hard drives with storage capacities over 528 MB, or other devices such as CD-ROM and tape drives.
SCSI: Small Computer System Interface (SCSI) is the fastest, most flexible, most reliable, but most expensive way to connect a hard drive and other devices to a computer. SCSI is pronounced “scuzzy.” SCSI can connect up to seven devices. These devices can include removable hard drives, CD-ROM drives, tape drives, scanners and printers. These are best used when the system will act as a sever or process large quantities of data.
Hardware Problems
Hard drive not found
Invalid drive or drive specification
Damaged boot record
Damaged FAT or root directory or bad sectors
Cannot boot from the hard drive
Drive retrieves and saves data slowly
File Systems
l FAT16
u Supported by all Windows systems
l FAT32 (and VFAT)
u Supported by Windows 95 Second Edition, Windows 98, Windows 2000, Windows XP
l NTFS
u Supported by Windows NT, Windows 2000, Windows XP
l Each logical drive has its own file system
Optical Disks
• Data are stored as “pits” and “lands”
• These are burned into a master disk by a high powered laser
• Master disk is reproduced mechanically by a stamping process
• Data surface is protected by a clear coating
• Data are read by sensing the reflection of laser light
• A pit scatters the light
• A land reflects the light
CD vs. DVD
- Compact Disk (CD)
n CD-ROM
n CD-R
n CD-RW
- Digital Versatile Disk (DVD)
n Shorter wavelength laser
l Smaller focus, smaller pits, closer tracks
- Capacity
n CD = 800 MB
n DVD = 4.7 GB
CD-ROM Data Organization
• Uses light generated by lasers to record and retrieve information
• Information is stored by varying the light reflectance characteristics of the medium
• Available in read-only (CD-ROM) and read/write formats
• 270,000 blocks of 2048 bytes each (typically)
• 270,000 ´ 2048 = 552,960,000 bytes
• Extensive error checking and correction (e.g., bad regions of the disk flagged)
• Substantial overhead for error correction and identifying blocks
• Capacity can be as high as 630 MB
|
CD-ROM |
Magnetic Disk |
|
• One spiral track (3 miles long!) |
• Multiple tracks of concentric circles |
|
• Constant bit density |
• Variable bit density |
|
• Disk speed varies (CLV, constant linear velocity) |
• Disk speed constant (CAV, constant angular velocity) |
|
• Constant transfer rate |
• Constant transfer rate |
|
• Capacity: 550 MB |
• Capacity: varies |
Magnetic Tape Systems
- Off-line storage of large amounts of data
- Back-up and archival storage
- Data organized into records and files
- Highest capacity
- Slowest
- Cheapest
CD’s
- Read-only; data physically embedded into disc surface
- Store data as pits and lands
- Use constant linear velocity (CLV) and constant angular velocity (CAV)
- Look for multisession feature
- Use precautions when handling
DVD
- Has large storage capacity (8.5 GB one side; 17 GB both sides)
- Uses UDF file system
- Uses MPEG-2 video compression; requires MPEG-2 controller to decode compressed data
- Stores audio in Dolby AC-2 compression
- Recently: HD-DVD and read-writable DVDs
A DVD-ROM drive is a device that reads information stored on DVD-ROM discs. DVD-ROM stands for Digital Versatile Disc-Read-Only Memory (DVD-R). Read-only means you cannot change the information stored on a disc. DVD-ROM disc is similar in size and shape to a CD-ROM disc, but can store a lot more information. DVD-R or DVD-RW are for computers. Usually DVD-RAM are for video players.
DVD-ROM drives can play DVD-Video discs, which hold full-length, full-screen movies with much better quality than videocassettes. Many DVD-Video discs allow you to change the way you view the movie, such as displaying subtitles. You may need special hardware, such as an MPEG-2 video decoder card, for the best playback of DVD-Video discs.
• A single DVD disc can store at least 4.7 GB of data, which equals over seven CD-ROM discs. Unlike a CD-ROM disc, a DVD disc can be single-sided or double-sided. Each side can store one or two layers of data. The speed of a DVD-ROM drive determines how quickly data can transfer from a disc to the computer. Current DVD-ROM drives commonly have a speed of 6X.
Installing a DVD Drive
Installing a DVD Drive
EC1003 UNIT IV
UNIT IV I/O PERIPHERALS 9
Parallel port – signals and timing diagram – IEEE1284 modes – asynchronous communication – serial port signals – video adapters – graphic accelerators – 3D graphics accelerator issues – DirectX – mice – modems – keyboards – sound boards – audio bench marks.
sound boards
l Have ports for external stereo speakers and microphone input
l May be Sound-blaster compatible
l Sampling accuracy is critical to performance
l Stages of computerized sound
u Convert from analog to digital (digitize)
u Store digital data in compressed data file
u Reproduce or synthesize sound (digital to analog)
Installing a Sound Card
l Process
u Physically install card in empty PCI slot on the motherboard
u Install sound card driver
u Install sound applications software
l Special considerations for Windows 2000/XP installations
Keyboard
- User presses or releases button
- Buttons read by on-board Intel 8048 Microcontroller
- Microcontroller De-bounces buttons
- Generates scan code(s)
- Prefixes extended keys with 224 (EOh)
- Microcontroller serially transmits Scan codes at 10,000 baud to parallel latch on motherboard
- IRQ1 Triggered when complete byte arrives.
- Data available at Port 60h
- Acknowledge Keyboard: (toggle bit 7 of port 61h)
(See Lab manual for details)
- INT9 Called to process keystroke (usually BIOS)
- Default BIOS routine tracks [shirft], [alt], [ctrl], [CapLock], [NumLock] status word
- Keyboard buffer holds keystrokes until read by INT16 (KBDIN)
Keyboard Switches
Keyboards use a variety of switch technologies.
Capacitive switches are considered to be non-mechanical because they do not physically complete a circuit like most other keyboard technologies.
Instead, current constantly flows through all parts of the key matrix. Each key is spring-loaded and has a tiny plate attached to the bottom of it.
When you press a key, it moves this plate closer to the plate below it. As the two plates move closer together,
the amount of current is flowing through the matrix changes.
The processor detects the change and interprets it as a key press for that location.
Capacitive switch keyboards are expensive, but they have a longer life than any other keyboard. Also, they do not have problems with bounce since the two surfaces never come into actual contact.
All of the other types of switches used in keyboards are mechanical in nature. Each provides a different level of audible and tactile response — the sounds and sensations that typing creates. Mechanical key switches include:
A parallel port is a type of interface found on computers (personal and otherwise) for connecting various peripherals.
It is also known as a printer port or Centronics port. The IEEE 1284 standard defines the bi-directional version of the port.
Parallel Interface
- Originally Designed for printers
- Provides 8-bit I/O
- Attaches via 25-pin or Centrontics connector
- Provides TTL-level (5V) external I/O
- Major Signals
|
Signal(s) |
Input/ |
Notes |
|
Data[7:0] |
Bidirectional |
Byte-wide data bus |
|
Strobe |
To device |
Write signal |
|
Busy |
From device |
Don’t send more data |
|
Ack |
From device |
Acknowledge (interrupt signal) |
|
Initialize |
To device |
Initialize external device |
|
Out of Paper |
From device |
Status signal |
·
- Writing to the parallel port
IEEE 1284 is a standard that defines bi-directional parallel communications between computers and other devices.
In the 1970s, Centronics developed the now familiar printer parallel interface that soon became a de facto standard.
The standard became non-standard as enhanced versions of the interface were developed, such as the HP Bitronics implementation released in 1992.
In 1991 the Network Printing Alliance was formed to develop a new standard. In March 1994, the IEEE 1284 specification was released.
The IEEE 1284 standard allows for faster throughput and bidirectional data flow with a theoretical maximum throughput of 4 megabits per second, with actual throughput around 2 megabits, depending on hardware.
In the printer venue, this allows for faster printing and back-channel status and management.
Since the new standard allowed the peripheral to send large amounts of data back to the host, devices that had previously used SCSI interfaces could be produced at a much lower cost. This included scanners, tape drives, hard disks,
computer networks connected directly via parallel interface, network adapters and other devices.
No longer was the consumer required to purchase an expensive SCSI card—they could simply use their built-in parallel interface.
These low-cost devices provided a platform to leapfrog the faster USB interface into its present popularity, displacing the parallel devices.
However, the parallel interface remains highly popular in the printer industry, with displacement by USB only in consumer models.
|
Transfer mode |
Distance (metre) |
Speed (bits per second) [3] |
|
Compatibility (SPP) |
2/10 |
360,360 |
|
Nibble |
2/10 |
3,174,603 |
|
Byte |
2/10 |
1,369,863 |
|
EPP |
2/10 |
2,000,000 |
|
ECP |
2/10 |
2,500,000 |
IEEE 1284 standards
- IEEE 1284-1994: Standard Signaling Method for a Bi-directional Parallel Peripheral Interface for Personal Computers
- IEEE 1284.1-1997: Transport Independent Printer/System Interface- a protocol for returning printer configuration and status
- IEEE 1284.2: Standard for Test, Measurement and Conformance to IEEE 1284 (not approved)
- IEEE 1284.3-2000: Interface and Protocol Extensions to IEEE 1284-Compliant Peripherals and Host Adapters- a protocol to allow sharing of the parallel port by multiple peripherals (daisy chaining)
- IEEE 1284.4-2000: Data Delivery and Logical Channels for IEEE 1284 Interfaces- allows a device to carry on multiple, concurrent exchanges of data
General
The IEEE 1284 standard was approved in march 1994 as the Standard Signaling Method for a Bidirectional Parallel Peripheral Interface for Personal Computers. And is the first approved standard for parallel transmission on PCs. The idea was to create a standard that was backward compatible with the old Centronics standard. With the new standard higher speeds and greater distances are possible plus there is the capability also sending to the host (bidirectional).
The maximum speed that is allow over the new parallel bus is 2 MBps (16 Mbps). The cable length is determend by the mode that is used. Within the IEEE 1284 there are 5 different modes defined:
- Compatibility mode
- Nibble mode
- Byte mode
- Enhanced Parallel Port (EPP)
- Extended Capability Port (ECP)
Compatibility mode
This one is compatible with all previous version of the parallel port. Data rates are possible up to 150 bytes per second @ 6 meter (20 ft) with an AB-cable or up to 150 kbps @ 10 meter (32.8 ft) with a CC-cable.
Nibble mode
This is a uni-directional interface. Only data transfers from periperal to host are possible. Data is send from the e.g. printer to the PC in a nibbles (4 bits). Combined with the Compatibility mode this is what Hewlett Packard calls “Bi-tronics”.
For the Nibble-mode speeds of up to 50 kbps @ 6 meter (20 t) are possible. With a CC-cable this can be increased to up to 150 kbps @ 10 meter (32.6 ft).
Byte mode
Byte mode makes it possible to send data from the peripheral to the host in bytes (8 bits). Combined with the Compatibility mode you have a “Bidirectional port”.
Speeds are possible up to 500 kbps @ 10 meter (32.8 ft) when CC-cables are used.
EPP mode
This is a mode in which data can be transfered from host to peripheral or vice versa, but not at the same time, so this is a half-duplex connection (mostly used by CD-ROMs, tape-drives, harddisks).
Speeds can range from 500 kbps to up to 2 Mbps @ 6 meter (20 ft) or 10 meter (32.8 ft) when CC-cables are used.
ECP mode
This is a mode in which data can be transfered from host to peripheral or vice versa, but not at the same time, so this is a half-duplex connection (mostly used by printers and scanners).
Speeds can range from 500 kbps to up to 1 Mbps @ 6 meter (20 ft) or 10 meter (32.8 ft) when CC-cables are used.
Every device can only be in one mode at a time. So the IEEE 1284 workgroup invented a way of determining which mode should be used with which device, that is called Negotiation. The Negotiation part doesn’t affect older devices, but IEEE 1284 compliant devices can tell the host what they are and which mode to use.
Cables and Connectors
The IEEE defined three types of connectors and six types of cables. The type A connector is the parallel port connector (Sub-D25) found on most computers. The type B connector is what is usually called the Centronics connector. And there is a new connector that is called MDR36 and which is called type C. The pinning for the Centronics and Sub-D25 is not changed.
The different cables that are defined are:
|
AMAM |
Type A male to type A male |
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AMAF |
Type A male to type A female |
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AB |
Type A male to type B |
|
AC |
Type A male to type C |
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BC |
Type B male to type C |
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CC |
Type C male to type C |
Also the cable characteristics are defined:
- The cable shield must be connected to the connector back shell using a 360° concentric method
- The shield must be minimal 85 % optical braid coverage over foil
- The maximum crosstalk is not greater then 10 %
- All signals are send over a twisted pair with their signal ground return
- Each pair must have an impedance of 62 ± 6 ohms @ 4 to 16 MHz
Asynchronous communication
- One definition of asynchronous: transmitter and receiver do not explicitly coordinate each data transmission
- Transmitter can wait arbitrarily long between transmissions
- Used, for example, when transmitter such as a keyboard may not always have data ready to send
- Asynchronous may also mean no explicit information about where data bits begin and end
Modem: (MODulator-DEModulator). The modem is simple in principle but complex in design.
It is used to transmit data over physically remote locations over traditional telephone lines. Unfortunately, phone lines cannot carry digital data: they are meant to carry sounds (analogue data). When sending data, the computer sends digital data to the modem.
The modem converts the digital 1’s and 0’s to sounds (e.g. High pitched sound for a one. Low pitched sound for a zero). This explains the “shushhhhhhhhhing” noise your modem makes when you connect to the internet: that noise is thousands of ones and zeroes being pumped down the phone line each second.
Converting digital data to sound is called modulation. The sound travels as noise over the phone line until it reaches the modem at the other end of the line. Because the other modem is in receiving mode, it listens to the sounds and converts the high and low pitched sounds back to ones and zeros (demodulation) and passing them to the computer. When the second computer wants to transmit, it switches from demodulation (listening) to modulation (talking), and sends data-sounds to the first modem which is now listening.
Modems are rated by speed: a 56K modem can transmit (a theoretical maximum of) about 56,000 ones and zeros per second.
Important note 1: the “K” in “56K” refers to BITS, not BYTES. While a 56K file on disk means “56 kilobytes” (56,000 bytes), “56K” in modems means “56 kiloBITS” which is roughly 5.6 kiloBYTES. Many people do not realise this. Amaze your friends at your next party with this pearl of wisdom.
Important note 2: 56K modems receive at 56K but can only transmit at 33.6K.
The problem with phone lines is that they were never designed to transmit 56,000 sounds per second with perfect accuracy. They were designed for grandma to chat to mum about scones. An occasional click or bit of static on the line does not bother granny but it can destroy entire computer conversations. If only one bit out of 70,000,000 is wrong, your entire downloaded file can be ruined.
Internal modems (that plug into an expansion slot inside the computer) have less intelligence and rely on the CPU to do a lot of their work – as do USB modems. External modems (that plug into a serial port) do all their work themselves and put less strain on the CPU.
video adapters
- The video adapter’s job is to store an in-memory representation of the currently displayed image on the video monitor. The adapter converts this representation to a signal understood by the monitor.
- This in-memory representation of the display consists of a 2-dimensional matrix of dots, called pixels (for Picture Elements). The dimensions of this matrix can vary depending upon the characteristics of the video adapter and the monitor; the larger the matrix, the more detail can be displayed onscreen at any time.
- Video adapters are equipped with their own RAM chips to store these matrices. Adapters with more memory can represent higher resolutions and/or numbers of colours, than can comparable adapters with less memory.
A video adapter (alternate terms include graphics card, display adapter, video card, video board and almost any combination of the words in these terms) is an integrated circuit card in a computer or, in some cases, a monitor that provides digital-to-analog conversion, video RAM, and a video controller so that data can be sent to a computer’s display. Today, almost all displays and video adapters adhere to a common denominator de facto standard, Video Graphics Array (VGA). VGA describes how data – essentially red, green, blue data streams – is passed between the computer and the display. It also describes the frame refresh rates in hertz. It also specifies the number and width of horizontal lines, which essentially amounts to specifying the resolution of the pixels that are created. VGA supports four different resolution settings and two related image refresh rates.
In addition to VGA, most displays today adhere to one or more standards set by the Video Electronics Standards Association (VESA). VESA defines how software can determine what capabilities a display has. It also identifies resolutions setting beyond those of VGA. These resolutions include 800 by 600, 1024 by 768, 1280 by 1024, and 1600 by 1200 pixels.
A board that plugs into a personal computer to give it display capabilities. The display capabilities of a computer, however, depend on both the logical circuitry (provided in the video adapter) and the display monitor. A monochrome monitor, for example, cannot display colors no matter how powerful the video adapter.
Many different types of video adapters are available for PCs. Most conform to one of the video standards defined by IBM or VESA.
Each adapter offers several different video modes. The two basic categories of video modes are text and graphics. In text mode, a monitor can display only ASCII characters. In graphics mode, a monitor can display any bit-mapped image. Within the text and graphics modes, some monitors also offer a choice of resolutions. At lower resolutions a monitor can display more colors.
Modern video adapters contain memory, so that the computer’s RAM is not used for storing displays. In addition, most adapters have their own graphics coprocessor for performing graphics calculations. These adapters are often called graphics accelerators.
Video adapters are also called video cards, video boards, video display boards, graphics cards and graphics adapters.
Microsoft DirectX is a collection of application programming interfaces (APIs) for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms. Originally, the names of these APIs all began with Direct, such as Direct3D, DirectDraw, DirectMusic, DirectPlay, DirectSound, and so forth. DirectX, then, was the generic term for all of these APIs and became the name of the collection. After the introduction of the Xbox, Microsoft has also released multiplatform game development APIs such as XInput, which are designed to supplement or replace individual DirectX components.
Direct3D (the 3D graphics API within DirectX) is widely used in the development of computer games for Microsoft Windows, Microsoft Xbox, and Microsoft Xbox 360. Direct3D is also used by other software applications for visualization and graphics tasks. In CAD/CAM engineering, for instance, it rivals the OpenGL by its ability to quickly render 3D graphics on DirectX-compatible graphics hardware. As Direct3D is the most widely publicized component of DirectX, it is common to see the names “DirectX” and “Direct3D” used interchangeably.
The DirectX software development kit (SDK) consists of runtime libraries in redistributable binary form, along with accompanying documentation and headers for use in coding. Originally, the runtimes were only installed by games or explicitly by the user. Windows 95 did not launch with DirectX, but DirectX was included with Windows 95 OEM Service Release 2.[1] Windows 98 and Windows NT 4.0 both shipped with DirectX, as has every version of Windows released since. The SDK is available as a free download. While the runtimes are proprietary, closed-source software, source code is provided for most of the SDK samples.
The latest versions of Direct3D, namely, Direct3D 10 and Direct3D 9Ex, are only officially available for Windows Vista, because each of these new versions were built to depend upon the new Windows Display Driver Model that was introduced for Windows Vista. The new Vista/WDDM graphics architecture includes a new video memory manager that supports virtualizing graphics hardware to multiple applications and services such as the Desktop Window Manager
In computing, a mouse (plural mice, mouse devices, or mouses) is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of a small case, held under one of the user’s hands, with one or more buttons. It sometimes features other elements, such as “wheels”, which allow the user to perform various system-dependent operations, or extra buttons or features can add more control or dimensional input. The mouse’s motion typically translates into the motion of a pointer on a display, which allows for fine control of a Graphical User Interface.
The name mouse, originated at the Stanford Research Institute, derives from the resemblance of early models (which had a cord attached to the rear part of the device, suggesting the idea of a tail) to the common mouse.[1].
Operating a mechanical mouse.
1: moving the mouse turns the ball.
2: X and Y rollers grip the ball and transfer movement.
3: Optical encoding disks include light holes.
4: Infrared LEDs shine through the disks.
5: Sensors gather light pulses to convert to X and Y velocities.
EC1003 UNIT II
UNIT II MOTHERBOARDS
Active motherboards – sockets and slots – Intel D850GB – Pentium4 mother board – expansion slots – form factor – upgrading a mother board – chipsets – north bridge – south bridge – CMOS – CMOS optimization tactics – configuring the standard CMOS setup – motherboard BIOS – POST – BIOS features – BIOS and Boot sequences – BIOS shortcomings and compatibility issues – power supplies and power management – concepts of switching regulation – potential power problems – power management.
Mother Board
Most modern motherboards have at least the following major components:
n Processes socket/slot
n Chipset
n Super i/o controller
n ROM bios
n RAM sockets
n Bus slots
n CPU voltage regulator
n Battery
mb, mainboard, mobo, mobd, backplane board, planar board, or system board. The Motherboard is a printed circuit that is the foundation of a computer and allows the CPU, RAM, and all other computer hardware components to function with each other. Below is a graphic illustration of the ASUS P5AD2-E motherboard and some basic explanations of each of the major portions of the motherboard
Sockets and slots
The motherboard has one or more sockets or slots into which the processor is inserted. The type of processor that can be used is defined by the type of socket or slot present on the motherboard. Intel has historically defined the processor socket standards, but competing chip makers have been able to use the same standards quite successfully
l Motherboard and processor must match
l Slots 1 and 2 are proprietary Intel slots
l Slot A and Socket A are proprietary AMD connectors
Socket 1
This is an old slot. Its found on 486 motherboards and supports 486 chips, plus the DX2, DX4 Overdrive. It contains 169 pins and operates at 5 volts. The only overdrive it will support is the DX4 Overdrive.
Socket 2
This Intel socket is a minor upgrade from the Socket 1. It has 238 pins and is still 5 volt. Although it is still a 486 socket and supports all the chips Socket 1 does, it has the minor addition of being able to support a Pentium OverDrive.
Socket 3
Another Intel socket, containing 237 pins. It operates at 5 volts, but has the added capability of operating at 3.3 volts, switchable with a jumper setting on the motherboard. It supports all of the Socket 2 processors with the addition of the 5×86. It is considered the latest of the 486 sockets.
Socket 4
We move into Pentium class machines with the Socket 4, by Intel. This socket has 273 pins. It operates at a whopping 5 volts. Due to this voltage and the lack of any multipliers, this socket basically had no where to go but the history books. It only supports the low-end Pentium 60-66 and the Overdrive because these chips are the only Pentiums operating at 5 volts. Beginning with the Pentium-75, Intel moved to the 3.3 volt chip.
Socket 5
This socket operates at 3.3 volts with 320 pins. It supports Pentium class chips from 75MHz to 133MHz. Newer chips will not fit because they need an extra pin. Socket 5 has been replaced by the more advanced Socket 7. There are socket converters out there that can allow you to run more modern socket 7 processors in these socket 5 sockets. While socket 7 processors are still old by today’s standards, these converters can allow you to get more life out of your socket 5 motherboard.
Socket 6
You might think this is a nice Pentium socket class, but it is meant for 486’s. It is only a slightly more advanced Socket 3 with 235 pins and 3.3 volt operation. This socket is forgotten. The market never moved to use it because it came out when 486’s were already going of out style and manufacturers couldn’t see pumping money into changing their designs for a 486.
Socket 7
Socket 7 was the most popular and widely used socket for quite awhile. It contains 321 pins and operates in the 2.5-3.3 volt range using a split voltage (different I/O voltage and core voltage). It supports all Pentium class chips, from 75MHz on up, MMX processors, the AMD K5, K6, K6-2, K6-3, 6×86, M2 and M3, and Pentium MMX Overdrives. This socket was the industry standard and was being used for sixth-generation chips by IDT, AMD and Cyrix. Intel, however, decided to abandon the socket for it’s sixth-generation lineup. Socket 7 boards incorporate the voltage regulator which makes voltages lower than the native 3.3 volt possible.
Socket 8
This is a high-end socket used for the Pentium Pro. It has 387 pins and operates at 3.1/3.3 volts. It is designed especially to handle the dual-cavity structure of the chip, so the socket is a bit longer than the others. It is more rectangular than other sockets, which are more square. Since Intel decided to move on to Slot 1, the Socket 8 is a sort of dead end unless you really want to use a Pentium Pro.
Slot 1
Intel completely changed the processor paradigm with this new format. Instead of the processor core being in a socketed package, Intel placed their 6th generation Pentium II onto a daughtercard. Whereas socket 7 boards typically had the L2 cache on the board itself, this daughtercard has the L2 cache on the card itself. This increases speed by allowing the processor to communicate quickly with the L2 cache without having to be limited to the speed of the system bus, as was the case with socket 7. Slot 1 itself has 242 pins and operates at 2.8-3.3 volts. The Slot 1 is used mainly for the P2,P3 and Celeron, but Pentium Pro users can use the slot by mounting their processors in a socket 8 on a daughtercard which is then inserted into the Slot 1. This converter gives Pentium Pro users the ability to upgrade later.
The release of this slot was mostly a competitive blow to AMD more than anything else. The socket designs previously used were not patented to be sure competitors could not use it. With the release of Slot 1, the wiring structure was patented so that no other manufacturer could use the design without approval from Intel. This is why we do not see any AMD processors making use of Slot 1. They had to create their own slot, slot A, to move onto the slotted interface.
Slot 1
Developed by Intel to replace their Zero Insertion Force (ZIF) sockets. Using Slot 1, the CPU is packaged in a 242-contact Single-Edge Contact Cartridge. The cartridge may contain up to two CPUs and an L2 cache. Intel’s Pentium II, Pentium III, and some Celeron processors use the Slot 1 configuration.
Slot 2
Essentially a 330-contact version of SLot 1. The Slot 2 cartridge may house as many as four processors and an L2 cache. Intel’s Xeon processor uses Slot 2.
Slot A
Developed by AMD, Slot A is mechanically similar to Intel’s Slot 1. However, the electrical requirements are different from Slot 1. AMD’s Athlon processor uses Slot A.
Intel® D850GB Motherboard
The Intel® D850GB Motherboard harnesses the advanced computing power of the
Intel® Pentium® 4 processor. Designed for the new Intel® 850 chipset, the Desktop
Board D850GB utilizes the Pentium 4 processor‘s full bandwidth and performance
with dual RAMBUS* channels and support for Intel® NetBurst™ micro-architecture.
The Intel® D850GB Desktop Board is the newest performance platform solution to
provide unprecedented system efficiency and responsiveness to stay on the cutting
edge of the Internet.
The Intel® D850GB Motherboard supports Intel NetBurst micro-architecture with
dual RDRAM* channels, providing 3.2 GB/second memory bus bandwidth to match
the Pentium 4 processor‘s system bus requirements. The new Intel 850 chipset also
supports system bus speeds of 400 MHz for performance improvements in high-
bandwidth and concurrent applications required for today’s emerging Web
technologies. The Intel® D850GB Motherboard is also designed to enhance overall
system performance with features such as Intel® Rapid BIOS Boot that speeds up
the Power on Self Test (POST), Communications and Networking Riser (CNR)* for
audio, modem, LAN and HPNA support, Ultra ATA/100 disk support; and four USB
ports. This ATX desktop board with five PCI slots, AGP 4X and Instantly Available™
PC (Suspend-to-RAM) is a proven-performance Intel® platform for the Pentium 4
processor.
Intel® Desktop Board D850GB Features and Benefits
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Features |
Benefits |
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Support for the Intel® Pentium® 4 Processor |
Supports 423-pin Pin Grid Array (PGA) package, and Intel® NetBurst™ micro-architecture which includes 400-MHz system bus. |
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Intel® 850 Chipset featuring Dual RDRAM* Channel Support |
Latest Intel® chipset to support the new Pentium 4 enhanced features. Delivers 3.2 GB/second bandwidth for maximum performance. |
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Intel® Rapid BIOS Boot |
Reduced boot time enables faster system availability. |
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Universal AGP 4X 1.5V Connector |
Supports the latest graphics technology. |
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Four RDRAM* RIMM Sockets |
Supports fast PC800, PC600 RDRAM* memory from 128 MB to 2 GB. |
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Ultra ATA/100 |
Faster disk I/O. |
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Five PCI Slots |
Expansion slots for custom system configurations and future add-in card upgrades. |
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Four USB Ports |
Dual-stack rear connectors and header for two front panel USB connectors. |
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Communication and Networking Riser (CNR) Support |
New technology that supports integrated LAN, HPNA, modem or audio cards for overall system cost savings and customization. |
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ATX Form Factor |
Form-factor standard for easy integration. |
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Instantly Available PC (Suspend-to-RAM) |
Power-management mode to reduce PC power consumption. Allows PC to behave like consumer electronic appliance. |
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Intel® Express Software Suite |
Software designed specifically for Intel® desktop boards and ease of integration. Suite includes:
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Hardware Management ASIC |
In coordination with Intel Active Monitor, allows remote monitoring of system conditions for lower total cost of ownership. |
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Three-year Limited Warranty |
Expanded investment protection. |
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Chipset |
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Intel 850® chipset |
Intel® 82850 Memory Controller Hub (MCH) with AHA (Accelerated Hub Architecture) bus |
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I/O Controller Hub (ICH2) |
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ICH2 I/O Controller Hub |
Ultra ATA/66/100 |
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I/O Features |
Integrated Super I/O LPC bus controller |
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USB |
Two USB controllers with four USB ports
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Firmware Hub |
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System BIOS |
4-Mb Flash EEPROM with Intel/AMI* BIOS featuring Plug and Play, IDE drive auto-configure |
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Intel® Rapid BIOS Boot |
Optimized POST delivers faster access to PC from power-on |
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System Memory |
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Memory Capacity |
Four 184-pin unbuffered RIMM sockets for 128 MB (min) to 2 GB (max) RDRAM |
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Memory Type |
PC600 or PC800 Dual-channel RDRAM |
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Memory Voltage |
2.5 V |
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Hardware Management Features |
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Voltage sense to detect out of range values |
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Front Panel Connector |
Reset, HD LED, Power LEDs, Power On/Off, Standby header, IR Port, Aux LED |
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Board Style |
ATX 2.03 compliant board size |
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Board Size |
(12.0″x9.6″) |
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Baseboard Power Requirements |
Utilizes new ATX12V spec with these requirements: |
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Operating Temperature |
0° C to +55° C |
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Storage Temperature |
-40° C to +70° C |
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FORM FACTOR
The form factor of a motherboard determines the specifications for its general shape and size. It also specifies what type of case and power supply will be supported, the placement of mounting holes, and the physical layout and organization of the board. Form factor is especially important if you build your own computer systems and need to ensure that you purchase the correct case and components. earlier). Some of the problems with this form factor mainly arose from the physical size of the board, which is 12″ wide, often causing the board to overlap with space required for the drive bays.
Following the AT form factor, the Baby AT form factor was introduced. With the Baby AT form factor the width of the motherboard was decreased from 12″ to 8.5″, limiting problems associated with overlapping on the drive bays’ turf. Baby AT became popular and was designed for peripheral devices — such as the keyboard, mouse, and video — to be contained on circuit boards that were connected by way of expansion slots on the motherboard. Baby AT was not without problems however. Computer memory itself advanced, and the Baby AT form factor had memory sockets at the front of the motherboard. As processors became larger, the Baby AT form factor did not allow for space to use a combination of processor, heatsink, and fan. The ATX form factor was then designed to overcome these issues
AT / ATX DIFFERENCES
Below is some of the ways in determining if your motherboard is an AT motherboard or an ATX motherboard.
The Keyboard:
AT Motherboard = 5 pin large connector
ATX Motherboard = 6 pin mini connector.
MB Power Connector:
AT Motherboard = Single Row two connectors 5v & 12v
ATX Motherboard = Double row single connector 5v,12v, and 3.3v
MOTHERBOARD ABCs
The motherboard is the main component found in PC and Macintosh computers. The motherboard is what allows various hardware components to transfer information to each other. As computers advanced, so did motherboards; below is a listing of the various Motherboard form factors.
Full-AT
Baby-AT
LPX
Full-ATX
Mini-ATX
NLX
Full-AT (12″ wide x 13.8″ deep) Matches the original IBM AT motherboard design, which only fits into full size AT or tower cases only, not being produced much any more, if any.
- This form factor is no longer produced because it cannot be placed into the popular Baby-AT chassis.
Baby-AT (8.57″ wide x 13.04″ deep) Almost the same as the original IBM XT motherboard with modifications in the screw hole position to fit into AT style case, with connections built onto the motherboard to fit the holes in the case.
- Specific placement of the keyboard and the I/O slots.
- This board also cannot be placed into the slimline case.
LPX (9.00″ wide x 13.00″ deep) Developed by Western Digital when making motherboards, which was duplicated by many other manufacturers and is no longer made by Western Digital.
- The LPX motherboard riser card contains all of the expansion slots.
- Placement of the video, parallel, two serial and PS/2 connections have changed locations.
Full-ATX – (12″ wide x 9.6″ deep) / Mini-ATX – (11.2″ wide x 8.2″ deep) The official specifications were released by Intel in 1995 and was revised to version 2.01 in February 1997. The ATX form factor is an advancement over previous AT style motherboards. Therefore requires a new case design. ATX is not an abbreviation, it is actually a trademark which belongs to Intel.
- The ATX motherboard has a stacked I/O connector panel mounted on the motherboard.
- On a socket 7 ATX motherboard, the socket has been placed a further distance from the expansion slots, allowing for long boards to be placed in easier.
- Single keyed internal power supply connector. This is the Molex power connector, ATX 2.01. Standby voltage needs to be greater than 720 mA. The connector now cannot be placed in improperly. While the Molex power connector allows for 5v and 3.3v to be connected, it is recommended that only a 3.3v be connected to the motherboard.
- Relocation of the memory and the CPU creating better ventilation and easier upgrade.
- Power management possible with proper BIOS support.
NLX (Supports motherboards with overall dimensions of 9.0″ x 13.6″ [maximum] to 8.0″ x 10.0″ [minimum]) Implemented in 1998 by Intel and is similar to the LPX form factor; however, includes several new improvements.
- Support for the Pentium II
- Support for AGP
- Support for USB.
- Support for DIMM.
- Easier Access to internal components
- Support for motherboards that can be removed without using tools.
Expansion Slot
A slot located inside a computer on the motherboard or riser board that allows additional boards to be connected to it. Below is a listing of some of the expansion slots commonly found in IBM compatible computers as well as other brands of computers and a graphic illustration of a motherboard and its expansion slots.
Common types of expansion slots:
- AGP Accelerated Graphics Port
- AMR Audio/Modem Riser
- CNR Communication and Network Riser
- EISA Extended Industry Standard Architecture,
- ISA Industry Standard Architecture
- PCI Peripheral Component Interconnect
- VESA Video Electronics Standard Association
Chipset
n The chipset is the mother board
n A chipset is a group of microcircuits that orchestrate the flow of data to and from key components of a PC
n Any two boards with the same chipsets the functionally identical
- A designated group of microchips that are designed to work with one or more related functions that were first introduced in 1987. When referring the the main motherboard chipset such as the Intel Chipsets, these chipsets will generally include the functions of the CPU, PCI, ISA, USB, etc… An example of an Intel chipset is the i820 or the Intel 820 chipset.
- late 1990s, Acer Laboratories (ALI), SIS and VIA Technologies all started developing chipsets for Intel, AMD and Cyrix processors
- 1998 PC’s 66MHz system bus finally being overcome., pushing Socket 7 chipsets to 100MHz.
- Intel responded with its 440BX, one of many Northbridge/Southbridge architecture.
- 1999, its single-minded commitment to Direct Rambus left Intel in the embarrassing position of not having a chipset that supported the 133MHz bus speed of its latest range of processors
- 2002 Intel 845d support DDR
Chips or Chips and Technologies is also a computer company. See our chips company information page for additional information about this company.
What is the chipset ?
· Contains the process that Interface bus (FSB)
· Contains the memory controllers
· Bus controllers
· I/O. controllers
· And more
· All of circuits of the mother board are contained within the chipset
Northbridge
An integrated circuit (generally Intel or VIA) that is responsible for the communications between the CPU interface, AGP, PCI and the memory. The Northbridge gets its name for commonly being North of the PCI bus. Below is a graphic illustration of the ASUS P5AD2-E motherboard and some basic explanations of each of the major portions of the motherboard, including the northbridge. As shown in the below picture, it’s common for the northbridge and southbridge to have a heatsink; in addition, the northbridge is usually slightly larger than the southbridge.
Southbridge
An integrated circuit ( generally Intel or VIA ) on the motherboard that is responsible for the hard disk drive controller, I/O controller and integrated hardware such as sound card or video card if present on the motherboard. The Southbridge gets its name for commonly being South of the PCI bus. Below is a graphic illustration of the ASUS P5AD2-E motherboard and some basic explanations of each of the major portions of the motherboard including the southbridge. As shown in the below picture, it’s common for the northbridge and southbridge to have a heatsink; in addition, the northbridge is usually slightly larger than the southbridge
CMOS (complementary metal-oxide semiconductor)
Also known as a RTC/NVRAM or CMOS RAM, CMOS is short for Complementary Metal-Oxide Semiconductor. CMOS is an on-board semiconductor chip powered by a CMOS battery inside IBM compatible computers that stores information such as the system time and system settings for your computer. A CMOS is similar to the Apple Macintosh computer’s PRAM.
Types of CMOS batteries – The following is a listing of the types of batteries found in computers to power the CMOS memory. The most common type of battery is the Coin cell battery (Lithium Battery). The coin cell battery is the size of a dime, as shown below.
Life time of a CMOS battery – The standard lifetime of a CMOS battery is around 10 Years; however, this amount of time can change depending on the use and environment that the computer resides.
CMOS (complementary metal-oxide semiconductor) is the semiconductor technology used in the transistors that are manufactured into most of today’s computer microchips. Semiconductors are made of silicon and germanium, materials which “sort of” conduct electricity, but not enthusiastically. Areas of these materials that are “doped” by adding impurities become full-scale conductors of either extra electrons with a negative charge (N-type transistors) or of positive charge carriers (P-type transistors). In CMOS technology, both kinds of transistors are used in a complementary way to form a current gate that forms an effective means of electrical control. CMOS transistors use almost no power when not needed. As the current direction changes more rapidly, however, the transistors become hot. This characteristic tends to limit the speed at which microprocessors can operate
BIOS (basic input/output system)
BIOS (basic input/output system) is the program a personal computer’s microprocessor uses to get the computer system started after you turn it on. It also manages data flow between the computer’s operating system and attached devices such as the hard disk , video adapter , keyboard , mouse , and printer .
BIOS is an integral part of your computer and comes with it when you bring it home. (In contrast, the operating system can either be preinstalled by the manufacturer or vendor or installed by the user.) BIOS is a program that is made accessible to the microprocessor on an eraseable programmable read-only memory ( EPROM ) chip. When you turn on your computer, the microprocessor passes control to the BIOS program, which is always located at the same place on EPROM.
When BIOS boots up (starts up) your computer, it first determines whether all of the attachments are in place and operational and then it loads the operating system (or key parts of it) into your computer’s random access memory ( RAM ) from your hard disk or diskette drive.
With BIOS, your operating system and its applications are freed from having to understand exact details (such as hardware addresses) about the attached input/output devices. When device details change, only the BIOS program needs to be changed. Sometimes this change can be made during your system setup. In any case, neither your operating system or any applications you use need to be changed.
Although BIOS is theoretically always the intermediary between the microprocessor and I/O device control information and data flow, in some cases, BIOS can arrange for data to flow directly to memory from devices (such as video cards) that require faster data flow to be effective.
What BIOS Does
The BIOS software has a number of different roles, but its most important role is to load the operating system. When you turn on your computer and the microprocessor tries to execute its first instruction, it has to get that instruction from somewhere. It cannot get it from the operating system because the operating system is located on a hard disk, and the microprocessor cannot get to it without some instructions that tell it how. The BIOS provides those instructions. Some of the other common tasks that the BIOS performs include:
· A power-on self-test (POST) for all of the different hardware components in the system to make sure everything is working properly
· Activating other BIOS chips on different cards installed in the computer – For example, SCSI and graphics cards often have their own BIOS chips.
· Providing a set of low-level routines that the operating system uses to interface to different hardware devices – It is these routines that give the BIOS its name. They manage things like the keyboard, the screen, and the serial and parallel ports, especially when the computer is booting.
· Managing a collection of settings for the hard disks, clock, etc.
The BIOS is special software that interfaces the major hardware components of your computer with the operating system. It is usually stored on a Flash memory chip on the motherboard, but sometimes the chip is another type of ROM.
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When you turn on your computer, the BIOS does several things. This is its usual sequence:
1. Check the CMOS Setup for custom settings
2. Load the interrupt handlers and device drivers
3. Initialize registers and power management
4. Perform the power-on self-test (POST)
5. Display system settings
6. Determine which devices are bootable
7. Initiate the bootstrap sequence
The first thing the BIOS does is check the information stored in a tiny (64 bytes) amount of RAM located on a complementary metal oxide semiconductor (CMOS) chip. The CMOS Setup provides detailed information particular to your system and can be altered as your system changes. The BIOS uses this information to modify or supplement its default programming as needed. We will talk more about these settings later.
Interrupt handlers are small pieces of software that act as translators between the hardware components and the operating system. For example, when you press a key on your keyboard, the signal is sent to the keyboard interrupt handler, which tells the CPU what it is and passes it on to the operating system. The device drivers are other pieces of software that identify the base hardware components such as keyboard, mouse, hard drive and floppy drive. Since the BIOS is constantly intercepting signals to and from the hardware, it is usually copied, or shadowed, into RAM to run faster
Booting the Computer
Whenever you turn on your computer, the first thing you see is the BIOS software doing its thing. On many machines, the BIOS displays text describing things like the amount of memory installed in your computer, the type of hard disk and so on. It turns out that, during this boot sequence, the BIOS is doing a remarkable amount of work to get your computer ready to run. This section briefly describes some of those activities for a typical PC.
After checking the CMOS Setup and loading the interrupt handlers, the BIOS determines whether the video card is operational. Most video cards have a miniature BIOS of their own that initializes the memory and graphics processor on the card. If they do not, there is usually video driver information on another ROM on the motherboard that the BIOS can load.
Next, the BIOS checks to see if this is a cold boot or a reboot. It does this by checking the value at memory address 0000:0472. A value of 1234h indicates a reboot, and the BIOS skips the rest of POST. Anything else is considered a cold boot.
If it is a cold boot, the BIOS verifies RAM by performing a read/write test of each memory address. It checks the PS/2 ports or USB ports for a keyboard and a mouse. It looks for a peripheral component interconnect (PCI) bus and, if it finds one, checks all the PCI cards. If the BIOS finds any errors during the POST, it will notify you by a series of beeps or a text message displayed on the screen. An error at this point is almost always a hardware problem.
The BIOS then displays some details about your system. This typically includes information about:
· The processor
· The floppy drive and hard drive
· Memory
· BIOS revision and date
· Display
Any special drivers, such as the ones for small computer system interface (SCSI) adapters, are loaded from the adapter, and the BIOS displays the information. The BIOS then looks at the sequence of storage devices identified as boot devices in the CMOS Setup. “Boot” is short for “bootstrap,” as in the old phrase, “Lift yourself up by your bootstraps.” Boot refers to the process of launching the operating system. The BIOS will try to initiate the boot sequence from the first device. If the BIOS does not find a device, it will try the next device in the list. If it does not find the proper files on a device, the startup process will halt. If you have ever left a floppy disk in the drive when you restarted your computer, you have probably seen this message.
The BIOS has tried to boot the computer off of the floppy disk left in the drive. Since it did not find the correct system files, it could not continue. Of course, this is an easy fix. Simply pop out the disk and press a key to continue.
Configuring BIOS
In the previous list, you saw that the BIOS checks the CMOS Setup for custom settings. Here’s what you do to change those settings.
To enter the CMOS Setup, you must press a certain key or combination of keys during the initial startup sequence. Most systems use “Esc,” “Del,” “F1,” “F2,” “Ctrl-Esc” or “Ctrl-Alt-Esc” to enter setup. There is usually a line of text at the bottom of the display that tells you “Press ___ to Enter Setup.”
Once you have entered setup, you will see a set of text screens with a number of options. Some of these are standard, while others vary according to the BIOS manufacturer. Common options include:
· System Time/Date – Set the system time and date
· Boot Sequence – The order that BIOS will try to load the operating system
· Plug and Play – A standard for auto-detecting connected devices; should be set to “Yes” if your computer and operating system both support it
· Mouse/Keyboard – “Enable Num Lock,” “Enable the Keyboard,” “Auto-Detect Mouse”…
· Drive Configuration – Configure hard drives, CD-ROM and floppy drives
· Memory – Direct the BIOS to shadow to a specific memory address
· Security – Set a password for accessing the computer
· Power Management – Select whether to use power management, as well as set the amount of time for standby and suspend
· Exit – Save your changes, discard your changes or restore default settings
Be very careful when making changes to setup. Incorrect settings may keep your computer from booting. When you are finished with your changes, you should choose “Save Changes” and exit. The BIOS will then restart your computer so that the new settings take effect.
The BIOS uses CMOS technology to save any changes made to the computer’s settings. With this technology, a small lithium or Ni-Cad battery can supply enough power to keep the data for years. In fact, some of the newer chips have a 10-year, tiny lithium battery built right into the CMOS chip!
Updating Your BIOS
Occasionally, a computer will need to have its BIOS updated. This is especially true of older machines. As new devices and standards arise, the BIOS needs to change in order to understand the new hardware. Since the BIOS is stored in some form of ROM, changing it is a bit harder than upgrading most other types of software.
To change the BIOS itself, you’ll probably need a special program from the computer or BIOS manufacturer. Look at the BIOS revision and date information displayed on system startup or check with your computer manufacturer to find out what type of BIOS you have. Then go to the BIOS manufacturer’s Web site to see if an upgrade is available. Download the upgrade and the utility program needed to install it. Sometimes the utility and update are combined in a single file to download. Copy the program, along with the BIOS update, onto a floppy disk. Restart your computer with the floppy disk in the drive, and the program erases the old BIOS and writes the new one. You can find a BIOS Wizard that will check your BIOS at BIOS Upgrades.
Major BIOS manufacturers include:
· American Megatrends Inc. (AMI)
· ALi
· Winbond
As with changes to the CMOS Setup, be careful when upgrading your BIOS. Make sure you are upgrading to a version that is compatible with your computer system. Otherwise, you could corrupt the BIOS, which means you won’t be able to boot your computer. If in doubt, check with your computer manufacturer to be sure you need to upgrade.
BIOS Beep Codes
- Whenever a recoverable error occurs during POST, the BIOS displays an error message describingthe problem (see Table 82).
- The BIOS also issues a beep code (one long tone followed by two short tones) during POST if the video configuration fails (a faulty video card or no card installed)
or if an external ROM module does not properly checksum to zero.
- An external ROM module (for example, a video BIOS) can also issue audible errors, usually consisting of one long tone followed by a series of short tones.
- For more information on the beep codes issued, check the documentation for that external device.
- There are several POST routines that issue a POST terminal error and shut down the system if they fail.
- Before shutting down the system, the terminal-error handler issues a beep code signifying the test point error, writes the error to I/O port 80h, attempts to initialize the video and writes the error in the upper left corner of the screen (using both monochrome and color adapters).
Table 82. Beep Codes
Beep Description
1 Refresh failure
2 Parity cannot be reset
3 First 64 KB memory failure
4 Timer not operational
5 Not used
6 8042 GateA20 cannot be toggled
7 Exception interrupt error
8 Display memory R/W error
9 Not used
10 CMOS Shutdown register test error
11 Invalid BIOS (e.g. POST module not found, etc.)
POST (Power on Self Test)
The computer POST (Power on Self Test) tests the computer, insuring that it meets the necessary system requirements and that all hardware is working properly before starting the remainder of the boot process. If the computer passes the POST the computer will have a single beep (with some computer BIOS manufacturers it may beep twice) as the computer starts and the computer will continue to start normally. However, if the computer fails the POST, the computer will either not beep at all or will generate a beep code, which tells the user the source of the problem.
The steps of a POST
Each time the computer boots up the computer must past the POST. Below is the common steps a POST performs each time your computer starts.
1. Test the power supply to ensure that it is turned on and that it releases its reset signal.
2. CPU must exit the reset status mode and thereafter be able to execute instructions.
3. BIOS checksum must be valid, meaning that it must be readable.
4. CMOS checksum must be valid, meaning that it must be readable.
5. CPU must be able to read all forms of memory such as the memory controller, memory bus, and memory module.
6. The first 64KB of memory must be operational and have the capability to be read and written to and from, and capable of containing the POST code.
7. I/O bus / controller must be accessible.
8. I/O bus must be able to write / read from the video subsystem and be able to read all video RAM.
An irregular POST is a beep code that is different from the standard one or two beeps. This could be either no beeps at all or a combination of different beeps indicating what is causing the computer not to past the POST.
9. If you’re receiving an irregular POST contains all the steps a user can do to resolve the issue or help determine what hardware has failed in the computer so it can be replaced. If you’re getting a beep code the remainder of this page contains a listing of each of the major manufacturers beep codes and what they each mean
AMI BIOS beep codes
Below are the AMI BIOS Beep codes that can occur. However, because of the wide variety of different computer manufacturers with this BIOS, the beep codes may vary.
BIOS Setup Program
Introduction
The BIOS Setup program can be used to view and change the BIOS settings for the computer. The BIOS Setup program is accessed by pressing the <F2> key after the Power-On Self-Test (POST) memory test begins and before the operating system boot begins. The menu bar is shown below.
Maintenance Main Advanced Security Power Boot Exit
Table 58 lists the BIOS Setup program menu features.
Table 58. BIOS Setup Program Menu Bar
Maintenance Main Advanced Security Power Boot Exit
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Clears passwords and BIS credentials and enables extended configuration mode
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Allocates resources for hardware components
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Configures advanced features available through the chipset Sets
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passwords and security features
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Configures power management features
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Selects boot options and power supply controls
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Saves or discards changes to Setup programoptions
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BIOS Security Features
· The BIOS includes security features that restrict access to the BIOS Setup program and who can
boot the computer. A supervisor password and a user password can be set for the BIOS Setup
program and for booting the computer, with the following restrictions:
· The supervisor password gives unrestricted access to view and change all the Setup options in
the BIOS Setup program. This is the supervisor mode.
· The user password gives restricted access to view and change Setup options in the BIOS Setup
program. This is the user mode.
· If only the supervisor password is set, pressing the <Enter> key at the password prompt of the
BIOS Setup program allows the user restricted access to Setup.
· If both the supervisor and user passwords are set, users can enter either the supervisor
password or the user password to access Setup. Users have access to Setup respective to
which password is entered.
· Setting the user password restricts who can boot the computer. The password prompt will be
displayed before the computer is booted. If only the supervisor password is set, the computer
boots without asking for a password. If both passwords are set, the user can enter either
password to boot the computer.
POWER SUPPLY ABCs
Supplies power throughout the computer. Power supplies convert potentially lethal 110-115 or 220-230 volt alternating current (AC) into a steady low-voltage direct current (DC) usable by the computer. A power supply is rated by the number of watts it generates.
WARNING: Do not open the power supply, it contains capacitors which can hold Electricity (WHICH CAN KILL) even if the computer is power off for a week, if not longer. If you do open it, WHICH IS NOT RECOMMENDED, take all precautions and ensure you work with one arm behind your back to direct the electricity away from the heart. Also ensure that you have no jewelry on (such as a watch or rings). However, again, THIS IS NOT RECOMMENDED, and still cannot protect you 100% and is still potentially dangerous. Because of these precautions, no extensive information will be found on this page about opening power supplies.
Currently in the industry there are eight power supply form factors. Each of these form factors can have various amounts of configurations and power output levels.
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PC / XT |
LPX |
POWER SUPPLY CONNECTOR
The below illustration is the typical female connector which would be used to connect to a device such as a CD-ROM or Hard Drive. This connector is refereed to as a large Molex connector. Additional to these types of connectors you may also find a small Molex which is generally used for the floppy disk drive.
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Pin |
Wire Color |
Signal |
|
1 |
Yellow |
+12v |
|
2 |
Black |
Ground |
|
3 |
Black |
Ground |
|
4 |
Red |
+5v |
POWER SUPPLY CONNECTIONS
|
Pin Number |
Color |
Function |
Connector |
|
1 |
Orange |
“Power Good” |
P8 |
|
2 |
Red (XT No Wire) |
+5V DC |
P8 |
|
3 |
Yellow |
+12V DC |
P8 |
|
4 |
Blue |
-12V DC |
P8 |
|
5 |
Black |
Ground |
P8 |
|
6 |
Black |
Ground |
P8 |
|
7 |
Black |
Ground |
P9 |
|
8 |
Black |
Ground |
P9 |
|
9 |
Black |
Ground |
P9 |
|
10 |
Yellow |
-5V DC |
P9 |
|
11 |
Red |
+5V DC |
P9 |
|
12 |
Red |
+5V DC |
P9 |
POWER MANAGEMENT
Power management was designed for convenience as it easier to have your computer go into power standby and be able to press a key on your keyboard or move your mouse and instantaneously be back where you were and for saving power. This is especially important on portable computers when using the battery as your main power source
Power Management Methods
l Advanced Power Management (APM)
l AT Attachment (ATA) for IDE drives
l Display Power Management Signaling (DPMS) standards for monitors and video cards
l Advanced Configuration and Power Interface (ACPI)
Power Management Features
l Green timer on the motherboard
l Doze time
l Standby time
l Suspend time
l Hard drive standby time
Power Management is a way for the computer to save power by turning off certain features of the computer such as the monitor, hard disk drives and other computer peripherals.
APM, or Advanced Power Management, is an Application Program Interface, or API, developed by Microsoft and Intel which allows computer and BIOS manufacturers to include Power Management into their BIOSes.
In the near future, ACPI, or Advanced Configuration and Power Interface, developed by Microsoft, Intel and Toshiba will be used which will essentially allow computers equipped with future operating systems and capable hardware to shutdown the computer temporarily. When the computer is turned back on or a button is pressed, the computer will immediately come on within a few seconds.
The loss of electricity to a computer, peripherals and/or other electronic devices. When a power failure occurs, any data currently in a temporary storage, such as in the computer’ memory, is immediately lost and unrecoverable. Power failures may also cause data corruption and, in some cases, hardware to go bad
Also known as a power cable, mains cable or flex a power cord is the primary cable that provides power to the computer, printer, monitor, and components within a computer. The image to the left is an example of the power cord that is commonly used with computers, monitors, printers, and many other peripherals.
Switched-Mode Power Supply, SMPS is a type of power supply that uses a switching regulator to control and stabilize the output voltage by switching the load current on and off. These types of power supplies offer a greater power conversion and reduce the overall power loss.
The power supply of a desktop PC, sometimes also referred to as a Silverbox (Figure 1), supplies all the power needed in a desktop PC. During normal operation a number of DC power supply voltages have to be provided: a 12, 5 and 3.3V supply voltage, a 5V standby supply, and a low current, less accurate –12V supply. The 12, 5 and 3.3V supplies must each be capable of supplying 20A or more with a voltage accuracy of ±5%. The average efficiency per today at maximum load is about 70 percent, so when 300W is delivered to the load about 100W of power is wasted and converted into heat, which is subsequently removed using heat sinks and fans.
Alternating current (AC)
Cycles back and forth
Economical
Direct current (DC)
Travels in only one direction, from hot to ground
Required by most electronic devices
Computer power supply functions as both a transformer and rectifier
Potential Outcomes of a Faulty Power Supply
l Memory errors
l Data errors
l System hangs
l System reboots
l Damage to a motherboard or other component
EC1003 COMPUTER HARDWARE AND INTERFACING
EC1003 COMPUTER HARDWARE AND INTERFACING 3 0 0 100
AIM
To enable the student to get a detailed knowledge of all the hardware components that make up a computer and to understand the different interfaces required for connecting these hardware devices.
OBJECTIVES
· To introduce issues related to CPU and memory.
· To understand the components on the motherboard
· To understand different storage media
· To introduce the features of different I/O peripheral devices and their interfaces.
UNIT I CPU AND MEMORY 9
CPU essentials – processor modes – modern CPU concepts – Architectural performance features – the Intel’s CPU – CPU over clocking – over clocking requirements – over clocking the system – over clocking the Intel processors – Essential memory concepts – memory organizations – memory packages – modules – logical memory organizations – memory considerations – memory types – memory techniques – selecting and installing memory.
UNIT II MOTHERBOARDS 9
Active motherboards – sockets and slots – Intel D850GB – Pentium4 mother board – expansion slots – form factor – upgrading a mother board – chipsets – north bridge – south bridge – CMOS – CMOS optimization tactics – configuring the standard CMOS setup – motherboard BIOS – POST – BIOS features – BIOS and Boot sequences – BIOS shortcomings and compatibility issues – power supplies and power management – concepts of switching regulation – potential power problems – power management.
UNIT III STORAGE DEVICES 9
The floppy drive – magnetic storage – magnetic recording principles – data and disk organization – floppy drive – hard drive – data organization and hard drive – sector layout – IDE drive standard and features – Hard drive electronics – CD-ROM drive – construction – CDROM electronics – DVD-ROM – DVD media – DVD drive and decoder.
UNIT IV I/O PERIPHERALS 9
Parallel port – signals and timing diagram – IEEE1284 modes – asynchronous communication – serial port signals – video adapters – graphic accelerators – 3D graphics accelerator issues – DirectX – mice – modems – keyboards – sound boards – audio bench marks.
UNIT V BUS ARCHITECTURE 9
Buses – Industry standard architecture (ISA), peripheral component Interconnect (PCI) – Accelerated Graphics port (AGP) – plug-and-play devices – SCSI concepts – USB architecture.
TOTAL : 45
TEXT BOOK
1. Stephen J.Bigelow, “Trouble Shooting, maintaining and Repairing PCs”, Tata McGraw-Hill, New Delhi, 2001.
REFERENCES
1. Craig Zacker & John Rourke, “The complete reference:PC hardware”, Tata McGraw-Hill, New Delhi, 2001.
2. Mike Meyers, “Introduction to PC Hardware and Trouble shooting”, Tata McGraw-Hill, New Delhi, 2003.
3. B.Govindarajulu, “IBM PC and Clones hardware trouble shooting and maintenance”, Tata McGraw-Hill, New Delhi, 2002.
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