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A+ Preparation. Lesson 2 Hardware continued and BIOS. Interrupts and DMA. An Interrupt is a request for attention from the processor. When the processor receives an interrupt, it suspends its current operations, saves the status of its work, and
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A+ Preparation Lesson 2 Hardware continued and BIOS
Interrupts and DMA An Interrupt is a request for attention from the processor. When the processor receives an interrupt, it suspends its current operations, saves the status of its work, and transfers control to a special routine known as an interrupt handler, which contains the instructions for dealing with the particular situation that caused the interrupt. Interrupt signals can come from a variety of sources. For example, every keystroke generates an interrupt signal. Interrupts are also generated by other devices, such as a printer, to indicate that some event has occurred. These are called hardware interrupts. Interrupt signals initiated by programs are called software interrupts. A software interrupt is also called a trap or an exception. IRQ Channels are how PC devices get Interrupts DMA Direct Memory Access -Some expansion boards, such as CD-ROM cards, are capable of accessing the computer's DMA channel. When you install the board, you must specify which DMA channel is to be used, which sometimes involves setting a jumper or DIP switch. Without DMA the CPU is typically fully occupied for the entire duration of the read or write operation, and is thus unavailable to perform other work
IRQ (Interrupt Request) for the x86 • IRQ 0 - System timer. Reserved for the system. Cannot be changed by a user. • IRQ 1 - Keyboard. Reserved for the system. Cannot be altered even if no keyboard is present or needed. • IRQ 2 - Cascaded signals from IRQs 8-15. A device configured to use IRQ 2 will actually be using IRQ 9 • IRQ 3 - COM2 (Default) and COM4 (User) serial ports • IRQ 4 - COM1 (Default) and COM3 (User) serial ports • IRQ 5 - LPT2 Parallel Port 2 or sound card • IRQ 6 - Floppy disk controller • IRQ 7 - LPT1 Parallel Port 1 or sound card (8-bit Sound Blaster and compatibles)
IRQ Continued • IRQ 8 - Real-time clock (RTC) • IRQ 9 - Free / Open interrupt / Available / SCSI. Any devices configured to use IRQ 2 will actually be using IRQ 9. • IRQ 10 - Free / Open interrupt / Available / SCSI • IRQ 11 - Free / Open interrupt / Available / SCSI • IRQ 12 - PS/2 connector Mouse. If no PS/2 connector mouse is used, this can be used for other peripherals • IRQ 13 - ISA / Math co-processor • IRQ 14 - Primary IDE. If no Primary IDE this can be changed • IRQ 15 - Secondary IDE
Jumpers and Dip Switches • Jumper pins (points to be connected by the jumper) are arranged in groups called jumper blocks, each group having at least one pair of contact points and often more. • Used to configure settings such as hard drive master/slave relationship. Note IDE drives have jumpers, SATA do not.
CDs and DVDs • CD 650 Meg to 1 Gig. 150 KB/second transfer rate. • 4.7 Gig on one side 9.4 Gig on both sides. 600kb to 1.3 MB/second transfer rate.
CD and DVD • CD Compact Disk • CD ROM: Read Only • CR-R : Recordable. Can write only once • CD-RW : Read and write multiple times • DVD ROM – Digital Versatile Disk – data is permanent • DVD – R Data can be written once • DVD+R: data can be written once (an alternative to DVD-R) • DVD+R DL: higher capacity/ double layer of DVD+R • DVD+RW : Can be written multiple times • DVD – RAM Data can be written multiple times • BD-R Blue Ray
Power Connectors • Berg, Molex, Serial ATA
External Connectors • Serial(9 PIN) • Parallel (25 pin, often used for printers) http://en.wikipedia.org/wiki/Parallel_port • USB • Video -15 pin 3 rows
Power Supply • A power supply is typically designed to convert 100-120 V (North America and Japan) or 220-240 V (Europe, Asia and Australia) AC power to low-voltage DC power for the PC. • Specifications • Mean Time Between Failures (MTBF) or Mean Time To Failure (MTTF) • Maximum Load Current • Efficiency (65% to 80% is common) • Form Factors • ATX (sometimes called ATX/NLX) can be used with ATX, Mini-ATX, Extended ATX, NLX, microATX, or FlexATX motherboards. • SFX () can be used with microATX, FlexATX, ATX, Mini-ATX, or NLX motherboards. • LPX () can be used with LPX, AT, Baby AT,or AT/ATX Combo motherboards Form factors http://www.pcguide.com/ref/power/sup/form_ATX.htm
Power supply specifications • Rated by DC power output in watts • Modern systems typically =>300 watts • Older systems <200 watts • Rating isn’t an indicator of power draw • Draws only the power needed to supply internal components
Standard outputs • +/- 5 V • +/- 12 V • + 3.3 V
Selecting the voltage • Set power supply to run on 110-120 VAC or 220-240 VAC • With computer off, slide switch • Usually located near power cord port
Cooling Methods • Heat sinks • CPU and case fans • Liquid cooling systems • Thermal compound
BIOS • Basic Input/Output System • Firmware that boots computer to the point of loading the OS • NEEDS Battery. If you change the battery you lose settings • Stored on EEPROM chips • Describes hard drive(s) • CD/DVD • Memory • Boot sequence
BIOS Continued • Standard CMOS settings • Hard drive, memory, video, system date/time, boot options, power management. • See http://www.computorcompanion.com/LPMArticle.asp?ID=76
BIOS Continued • Advanced BIOS Features
Update/Flash the BIOS Determine current BIOS version Go to PC manufacturer’s Web support pages Compare available updates with current version Download new BIOS version Download flashing utility Close all open windows Open flashing utility; follow instructions Restart PC
BIOS update rules to follow • Don’t update your BIOS unless you must • Never turn off your computer during a BIOS update • Connect to a UPS • Use the correct BIOS flash utility • Follow instructions exactly • Back up BIOS if possible
Advanced Configuration and Power Interface • Advanced Configuration and Power Interface (ACPI) specification provides an open standard for unified operating system-centric device configuration and power management. ACPI, first released in December 1996, defines platform-independent interfaces for hardware discovery, configuration, power management and monitoring. The specification is central to Operating System-directed configuration and Power Management (OSPM); a term used to describe a system implementing ACPI, which therefore removes device management responsibilities from legacy firmware interfaces.
POST • Power On Self Test • Power supply • CPU • BIOS • BIOS memory • Memory • I/BUS
Labs • Using a lab computer • Open the bios (press f2 or delete during bootup) • find the boot order • Find information on memory and video Time: 15 minutes
CD and DVD • CD Compact Disk • CD ROM: Read Only • CR-R : Recordable. Can write only once • CD-RW : Read and write multiple times • DVD ROM – Digital Versatile Disk – data is permanent • DVD – R Data can be written once • DVD+R: data can be written once (an alternative to DVD-R) • DVD+R DL: higher capacity/ double layer of DVD+R • DVD+RW : Can be written multiple times • DVD – RAM Data can be written multiple times • BD-R Blue Ray
Cooling Methods • Heat sinks • CPU and case fans • Liquid cooling systems • Thermal compound
64 bit, what is it all about? • What does it mean? 8 bit, 16 bit, 32 bit, 64 bit? • Size of memory addresses • The terms 32-bit and 64-bit refer to the way a computer's processor (also called a CPU), handles information. The 64-bit version of Windows handles large amounts of random access memory (RAM) more effectively than a 32-bit system • A 32-bit register means that 232 addresses, or 4 gigabytes of memory (4.294 to be specific) can be used. • a 64 bit register means that 264 address, or 16 terabytes(18446744073 meg to be specific) That is just theoretical. No OS can support that. However 64 bit Windows Server can support up to up to 1,024 GB of memory. • Is the data bus also 64 bit or just the CPU?
Videos • BIOS http://www.youtube.com/watch?v=qKaKj6uRLSM • BIOS 2 http://www.youtube.com/watch?v=VLaoajhiN_k&feature=related • BIOS 3 http://www.youtube.com/watch?v=exU85jk9UyM&feature=related
Labs NOTE THIS IS A REPEAT LAB Lab 1: Disassemble a PC down to Motherboard and case (i.e. do not remove the motherboard). Then let the instructor verify that you have disassembled it fully then reassemble it and verify it works Make sure it boots up before you disassemble it Take out the following items All drives (HD, floppy, CD) All RAM All expansion cards If this is new to you, feel free to use a cell phone or other device to take a picture of how it is put together before you disassemble. 4. Make sure you take your time and pay attention to what you are doing TIME: 20minutes