Computer Hardware PC Components

Motherboard components 1.Ports 2.ISA Slot 3.PCI Slots 4.AGP Slot 5.CPU Slot 6.Chipset 7.Power connector 8.Memory sockets 9.I/O connectors 10.Battery 11.Chipset 12.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 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 TypeData BitsBus Clock Speed ISA/EISA8 and 16 bit8Mhz PCI16 bit66Mhz AGP (Accelerated Graphic Port) 16 bit66Mhz/ 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) DeviceCapacityAccess Time (milliseconds) Data Transfer Rate (Mb/sec) IDE Hard Disk>40 Gb10-16ms (IDE) 7-15ms (SCSI) <3MB/s to 33.3 MB/s 5 MB/s to 40MB/s CD Drive (52 speed) 650 – 700 Mb1X=150Kb/s, 3.3 – 7.5 Mb/s Burst mode – up to 33M bytes/sec Floppy Disk1.44Mb “Zip” Disk100Mb (250Mb)2.4Mb/s DVD Drives4.7Gb11Mb/s (DVD content 3.6Mb/s (CD 8 speed “DAT” Backup2Gb “DLT” Backup35/70GbTypical – 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, ATX 200 watt with cooling fan ATX 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 specifications 15" standard, 17"/19"/21" XVGA Resolution up to 2048 X 1536 Colour depth – 32bit True Colour (Dependant on Video Card) LCD technology – optimised for highest resolution e.g 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