Computer Hardware

PC Components

Motherboard components

1.Ports2.ISA Slot3.PCI Slots4.AGP Slot5.CPU Slot6.Chipset7.Power connector8.Memory sockets9.I/O connectors10.Battery11.Chipset12.BIOS chip (ROM)

Motherboard Chipsets Facilities provided depend on the supporting (Intel) chipset e.g.:- 430TX – supports

Pentium processor Max SDRAM memory up to 256Mb ISA and PCI expansion UDMA (Ultra Direct Memory Access) Battery charge monitoring (for mobile computing)

815E – supports PIII processor and Celeron FSB speeds up to 133Mhz SDRAM memory of to 512Mb at 133Mhz AGP expansion slots Ultra ATA IDE

860 - supports Xeon processors 4096Mb ram RDRAM FSB speeds of 400Mhz

Memory types

Manufacturers are always looking for faster memory access times, measured in nano-seconds… 30-Pin 72-Pin SDRAM PC66 SDRAM PC100 SDRAM PC133 SDRAM PC150 DIMMs Buffered DIMMs Unbuffered RDRAM/Rambus DDR RAM Apple/Mac Memory Laptop SODIMMs Camera/Flash RAM

M/B Expansion slots

Slot Type Data Bits Bus Clock Speed

ISA/EISA 8 and 16 bit 8Mhz

PCI 16 bit 66Mhz

AGP (Accelerated Graphic Port)

16 bit 66Mhz/100Mhz/133Mhz

IRQ,DMA,I/O,Memory Range

Most devices need an interrupt request (IRQ) and I/O address, some need DMA and/or a Memory Range

IRQ’s are hardware lines over which devices can send signals to get the attention of the processor when the device is ready to accept or send information.

Interrupt request (IRQ) lines are numbered from 0 to 15.

Each device must have a unique IRQ line. Not all are available to plug-in devices.

DMA (Direct Memory Access)

Memory access that does not involve the microprocessor.

DMA is frequently used for data transfer directly between memory and a peripheral device such as a disk drive or sound card.

Is faster than using the microprocessor to control the access

I/O Port Addresses

A channel through which data is transferred between a device and the microprocessor.

The port appears to the microprocessor as one or more memory addresses that it can use to send or receive data.

Input/output port is also called I/O port.

Memory range

A portion of computer memory that can be allocated to a device or used by a program or the operating system.

Devices are usually allocated a range of memory addresses for temporary storage during operation.

Viewing devices in Windows

Video Cards

Provide the computer with video output. Some include an additional graphics processor for additional speed.

Increased on-board memory allows for higher resolution and colour depth

3DFx “Voodoo” – mainly for gaming, include an on-board graphics processor rather than use the main CPU

Mass storage devices

IDE, EIDE, UDMA Hard drives SCSI Hard drives ZIP/JAZZ drives and disks Floppy disk CDR and CDRW DVD Drives Backup tapes

Storage Comparison (Typical)Device Capacity Access Time

(milliseconds)Data Transfer Rate(Mb/sec)

IDE Hard Disk >40 Gb 10-16ms (IDE)

7-15ms (SCSI)

<3MB/s to 33.3 MB/s

5 MB/s to 40MB/s

CD Drive

(52 speed)

650 – 700 Mb 1X=150Kb/s, 3.3 – 7.5 Mb/sBurst mode – up to 33M bytes/sec

Floppy Disk 1.44Mb

“Zip” Disk 100Mb (250Mb) 2.4Mb/s

DVD Drives 4.7Gb 11Mb/s (DVD content3.6Mb/s (CD content)@ 8 speed

“DAT” Backup 2Gb

“DLT” Backup 35/70Gb Typical – 1.5MB/s

Sound devices

Standard 16 bit cards On board wavetable sounds

midi instrument emulation Software wavetable sounds Soundblaster AWE64, SB128, SBLive! Yamaha professional cards

PC Cases

Power Supplies – AT, ATX200 watt with cooling fanATX PSU support Windows Shutdown

Tower or Desktop case types

Internal Connecting Cables

Power cables IDE and EIDE cables Floppy drive cables Sound card and CD audio SDIF digital cable Case LED cables

External connecting cables

15 PIN VGA 9 PIN RS232 (serial) 25 PIN Parallel USB FireWire Internal Modem RJ45 Network connection PCMCIA Cards (mainly for laptop

computers)

Input devices

Pointing and Keyboard devices Graphics tablets Joysticks Light pens

(Visual) Output devices

Monitor types and specifications15" standard, 17"/19"/21" XVGAResolution up to 2048 X 1536Colour depth – 32bit True Colour (Dependant on Video Card)

LCD technology – optimised for highest resolution e.g. 1280 X 1024

(Hard copy) Output Devices

Laser Printers (Mono and Colour) Dot Matrix Ink Jet Plotters

Choices and Justification

When upgrading or providing new equipment for a customer always remember that it is normal to provide at least two solutions

Always realise that you should always be able to justify your choices