Hardware: SAS Flashcards
What is a super computer?
Most powerful + expensive computers available today.
What is a server?
Computer used as the central computer in a network. A rack server might be used by a large business/school.
What would a lack of RAM do?
Slow the computer when editing a large video file.
What is CPU speed measured in?
Hertz.
Why is it important to update computer’s anti-virus?
Protect against new malware. A worm is a type of virus.
What does an OS do?
Controls overall computer function + allows hardware to interact with applications.
What is a browser?
Application used to navigate internet.
What is a computational thinker?
Someone who thinks/expresses solutions like a computer.
What is a PC?
Specifically related to original IBM PC (1981) concept. New systems were referred to as IBM compatible + many PC terms refer back to IBM PC, PC/XT, PC/AT.
What is in PC?
Motherboard, processor (Intel compatible), memory, storage devices (HDD, DVD, CD, FDD), keyboard, video, mouse (KVM), operating system.
What is the processor?
Central Processing Unit (CPU), ‘engine’ of PC.
What is the PSU?
Power Supply Unit. Converts AC supply to DC supply for PC, good PSU helps voltage regulation, eliminating mains supply spikes + surges. Rated in wattage, more powerful = more watts. Also cools. Reduces high voltage to lower voltage for buses.
Better not to buy cheap PSU, high quality provides clean, stable power + low noise/heat. PSU fan works hard + often spindle bearings break down. PC noisy, so may replace when this happens. Failing HDDs become noisy so ensure it’s PSU, not HDD. Try powering up w/out HDD connected to check.
Modular ports allow you to attach cables that carry power to components. Modular means you only have to attach cables for components you have. Fan expels hot air as PSUs gen lots of heat.
PSU takes power from wall socket. PSUs rated from 200W to 1600W so must ensure you have enough wattage.
8 pin ATX carries power from PSU to CPU. 24 pin ATX carries power from PSU to motherboard. 6 pin Express carries power from PSU to HDD.
What is memory?
RAM is primary memory, holds programs + data used by CPU.
What is MIPS?
Millions of Instructions per second. Method of measuring raw speed of CPU. Higher clock speed + more cores makes computers faster (more MIPS).
What are removable media drives?
Floppy Disk Drive/FDD (simple inexpensive removable, now only external option), Optical Drives (CD, DVD, BD/Blu-Ray), USB Flash Drives + SD Cards.
What is storage?
Hard Disk Drives/HDD (Primary archival storage media, refers to both disk + mechanism controlling positioning, reading + writing to & from it), cables, sockets + connectors (IDE, SCSI, SATA, DC power, all keyed for correct connection)
What are hardware components?
Video, audio + comms ports – Embedded graphics adaptors + sound adaptors, graphics cards & sound cards, display ports (VGA, DVI, HDMI), keyboard + mouse ports, parallel, serial, universal bus ports (USB)
Displays/Monitors: Cathode Ray Tube (CRT), Liquid Crystal Display (LCD), Thin Film Transistor (TFT), projectors.
What are the 4 functions of BIOS?
POST (Power On Self Test), Set-up (Configure motherboard/chipset settings), bootstrap loading + BIOS (Basic Input/Output System)
What is POST ?
Power On Self Test. Press power button, motherboard sends signal to PSU to start (PSU fans start if present), alt current stabilised for devices (taken down to 12V). When PSU power output stable, sends ‘power good’ signal to motherboard, components begin to power up + power LED comes on. During POST, see + hear activity on Disk drive LEDs, keyboard & mouse. POST also tests CPU, memory configs, IO devices + ports. POST checks RAM by writing & reading data, monitor displays this progress. Initialises on-board devices. POST tests your computer’s processor, memory, chipset, video adapters, disk controllers, disk drivers, key boards, and other components.
What are beep codes?
Beep Codes: Bios manufacturers (AMI, Phoenix, Intel) have diff codes, defined in doc in each system. Successful POST gens 1 beep (except on Compaq, 2 beeps).
What is a cold boot?
Mains power has just been supplied to PC.
What is a warm boot?
Power on + booting process restarted (ctrl, alt, del) e.g. completing installation/windows updates. Does mini POST, RAM not tested, BIOS determines which boot by checking address in memory.
What is the power switch?
Turn on power supply, physical switch on PSU.
What is the power button?
Button on case connected to pins in motherboard.
How does CPU initialise itself?
Resets internal registers, then jumps to start of ROM BIOS program + executes it. Instruction there executes POST before trying to boot OS.
What does BIOS do?
Manages basic config as defined in CMOS memory. Access to BIOS setup utility via password to protect user settings. Most systems use F1/F2/DEL during powerup. During bootup, basic utility drivers (programs) for keyboard, mouse, disk drives + vids loaded from BIOS. Newer comps have fancy BIOS (e.g mouse driven) or have OS (Apple). BIOS info preset by manufacturer + user configurable as required. BIOS has 2 passwords (user/system + supervisor/setup) If password forgotten, reset CMOS) Can lock BIOS to stop OS installs etc.
What is CMOS?
Complementary Metal-Oxide-Semiconductor. CMOS mem contains all PC details (number, type + size of disk drives, mem size, which disk drive OS loaded from). Most displayed on screen. Small battery used to maintain CMOS content. RTC (Real Time Clock) as power real-time-clock chip. Battery failure can cause info loss + booting issues. Windows + Anti-virus updates also not applied as they check date. Indicator of this is date + time errors. CR2031 battery commonly used. CMOS memory contains basic system config.
How can you reset CMOS battery?
Jumper (short) 2 pins on motherboard or remove battery. Can clear CMOS: turn off peripheral devices connected to comp, disconnect power cord from AC power source, remove comp cover, find battery, remove battery, wait 1-5 mins, reconnect battery, put comp cover back on.
What is bootstrapping?
Loads master boot record (MBR) from boot disk, MBR code checks drive has valid partition table. If ok, MBR loads 1st bootable partition (volume boot record), checks this & runs code.
What is true of BIOS versions?
Most have flash BIOS, can be updated as necessary. Can check BIOS date + version (system info). Regular BIOS updates provided by manufacturer. Updates/patches to support latest devices (processors, HDDs, new network cards). Updating BIOS can fix bugs/add features, get from MOTHERBOARD manufacturer, not BIOS manufacturer.
How might you update BIOS?
Windows executable, BIOS setup, bootable media, emergency flash BIOS. Possible to brick comp, some systems have 2 BIOS chips.
What are the limitations of BIOS?
Max size restricted, restricted ability (16 bit instructions), hard-disk type restricted, can only boot from MBR formatted HD (limits max size to 2.2Tb), replaced by UEFI (Unified Extensible Firmware Interface).
What is a motherboard?
Heart of PC, all components in PC, CPU, Memory, keyboard, mouse, video + peripherals linked here. Characteristics of form factor + chipset. Motherboards have varied I/O requirements + connections, speed of change means new ports coming constantly, hard-wiring ports into case for all connections inflexible + unfeasible. Back of case has ‘open slot’ so motherboard pokes ports through, protected by I/O shield which comes with motherboard.
CPU Socket is where CPU sits, it has shield that holds in place. Front panel headers are where you attach all ports + buttons on case to motherboard.
There are RAM slots where RAM goes, only allow 1 type of RAM, most motherboards have between 2 and 8 slots. IO ports are where you plug in peripherals.
Motherboards need enough power to run components attached to them so usually have more than 1 connector to PSU. Motherboard screwed into case using standoffs which hold it away from metal of case. HDD SATA (serial ATA) port, hard drive connects here. Provides connectivity between processor + expansion slots.
What is form factor?
Defines physical properties (size, layout, power, mounting hole positions, connector types). E.g. AT (12 X 13.8”), Baby AT, BTX (12.8 x 10.5), Micro BTX (10.4 x 10.5)
Cases come in multiple sizes + shapes (form factors) each designed to accept specific motherboard form factors + PSU. Main sizes: Tower (takes ATX, uATX, mini-ITX boards), Midi tower (ATX, uATX, mini-ITX boards), Mini tower (uATX, mini-ITX boards), Desktop/Low Profile (uATX, mini-ITX boards).
What is chipset?
Define which CPUs supported, speed + type of RAM used + interfaces supported. Chipset defined in 2 sections: Southbridge & Northbridge (Intel MCH & ICH)
What is the Northbridge chip?
Interface CPU with mem + graphics.
What is the Southbridge chip?
Looks after bus + peripheral interfaces.
What are the issues with cases?
Case reduces EMF interference to/from PC, full height PCI card won’t fit low profile case, tower most suitable for floor standing, not desk, for cooling, always keep slot panels installed so keep when installing PCI cards etc, ‘screwless design’?, lockable?, quality.
What do filters do?
Protect against mains power surges.
Over voltage: internal components protect against over-voltage (short time).
RFI filtering: ferrite cores suppress radio frequency emissions.
Surge protection: clamp voltage, clamp speed, energy absorption/dissipation.
What is UPS?
Uninterruptible power supplies. Includes battery/batteries to maintain power in event of power outage. Keeps PC running so data saved + normal shutdown implemented. Protects against mains surges + dips (brown outs). Many provide software tool to provide shutdown procedures in case of power failure while users away i.e. tools for monitoring UPS state + mains supply state.