PC Maintenance: PC Maintenance: Preparing for A+ Preparing for A+

CertificationCertificationChapter 11: Disk Drive InterfacesChapter 11: Disk Drive Interfaces

Chapter 11 ObjectivesChapter 11 Objectives

Understand floppy drive interfacesUnderstand floppy drive interfaces Explain IDE and ATA standardsExplain IDE and ATA standards Set jumpers for ATA drive installationSet jumpers for ATA drive installation Explain SCSI standardsExplain SCSI standards Set jumpers for SCSI drive installationSet jumpers for SCSI drive installation Physically install hard drivesPhysically install hard drives Troubleshoot drive problemsTroubleshoot drive problems

Drive Interface OverviewDrive Interface Overview

FloppyFloppy Integrated Device Electronics (IDE)Integrated Device Electronics (IDE) Small Computer Systems Interface (SCSI)Small Computer Systems Interface (SCSI) Universal Serial Bus (USB)Universal Serial Bus (USB)

Drive Interface ControllersDrive Interface Controllers

Floppy InterfaceFloppy Interface

34-pin connector and ribbon cable34-pin connector and ribbon cable Usually labeled FDDUsually labeled FDD Only one per motherboardOnly one per motherboard Supports two drives (A and B)Supports two drives (A and B)

Floppy Drive CableFloppy Drive Cable

Twist in a few Twist in a few wires between wires between first and second first and second drive connectorsdrive connectors

Older cables may Older cables may have alternate have alternate connector for connector for 5.25” floppy drive5.25” floppy drive

Floppy Drive CableFloppy Drive Cable

IDE InterfaceIDE Interface

40-pin connector and ribbon cable40-pin connector and ribbon cable Most motherboards have twoMost motherboards have two Each supports two drives (for a total of 4)Each supports two drives (for a total of 4) Hard disks, CD drives, ZIP drives, tape Hard disks, CD drives, ZIP drives, tape

backup drivesbackup drives

IDE VersionsIDE Versions

XT IDE (8-bit ISA): The original standard, XT IDE (8-bit ISA): The original standard, for XT computers. Obsoletefor XT computers. Obsolete

MCA IDE (16-bit Micro Channel): MCA IDE (16-bit Micro Channel): Proprietary standard by IBM. ObsoleteProprietary standard by IBM. Obsolete

ATA IDE (16-bit ISA): Current standard ATA IDE (16-bit ISA): Current standard

ATA VersionsATA Versions

ATA-1:ATA-1: The original standard The original standard ATA-2:ATA-2: Added support for other drives Added support for other drives

than hard disksthan hard disks ATA-3:ATA-3: Added SMART error detection Added SMART error detection ATA-4:ATA-4: Introduced UltraDMA/33, Introduced UltraDMA/33,

33MB/sec33MB/sec

ATA VersionsATA Versions

ATA-5:ATA-5: UltraDMA/66, 66MB/sec UltraDMA/66, 66MB/secATA-6:ATA-6: UltraDMA/100, 100MB/sec UltraDMA/100, 100MB/secATA-7:ATA-7: UltraDMA/133, 133MB/sec UltraDMA/133, 133MB/sec

UltraDMA modes above /33 UltraDMA modes above /33 require 80-wire ribbon cablerequire 80-wire ribbon cable

ATA Ribbon CablesATA Ribbon Cables

Serial ATASerial ATA

High-speed serial connection between High-speed serial connection between motherboard and drivemotherboard and drive

Serial cables can be longer than parallel Serial cables can be longer than parallel onesones

Cables are easier to work withCables are easier to work with Speeds of 150MB/sec and higher possibleSpeeds of 150MB/sec and higher possible

Slave/Master JumpersSlave/Master Jumpers

Two IDE devices per cableTwo IDE devices per cable First drive is First drive is MasterMaster (if second drive is also (if second drive is also

present) or present) or SingleSingle (if alone) (if alone) Not all drives distinguish between Master Not all drives distinguish between Master

and Singleand Single Second drive is Second drive is SlaveSlave Cable SelectCable Select setting relies on position on setting relies on position on

ribbon cable to determine Master/Slave ribbon cable to determine Master/Slave statusstatus

Slave/Master JumpersSlave/Master Jumpers

Mixing IDE DrivesMixing IDE Drives

On a single cable, all drives will revert to On a single cable, all drives will revert to slowest ATA standard (speed) that is in slowest ATA standard (speed) that is in commoncommon

Example: UltraDMA/33 and UltraDMA/100 Example: UltraDMA/33 and UltraDMA/100 drives together will operate at 33MB/secdrives together will operate at 33MB/sec

SCSI InterfaceSCSI Interface

Small Computer Systems InterfaceSmall Computer Systems Interface Popular on high-end systems, serversPopular on high-end systems, servers More expensive than IDEMore expensive than IDE Interface not built into most motherboardsInterface not built into most motherboards Requires controller cardRequires controller card Serial ATA promises to further erode the Serial ATA promises to further erode the

SCSI marketSCSI market

SCSI Advantages over IDESCSI Advantages over IDE

Historically, overall higher throughputHistorically, overall higher throughput Multiple SCSI drives can be chained Multiple SCSI drives can be chained

together (at least 7), making SCSI well together (at least 7), making SCSI well suited for RAIDssuited for RAIDs

Drives on same bus can share bandwidth Drives on same bus can share bandwidth better than IDE better than IDE

Types of SCSITypes of SCSI

SCSI-1: The originalSCSI-1: The original 8-bit, 5Mhz bus8-bit, 5Mhz bus Lack of standardizationLack of standardization Device and expansion card typically Device and expansion card typically

purchased together as proprietary pairpurchased together as proprietary pair

Types of SCSITypes of SCSI

SCSI-2: Standardized SCSISCSI-2: Standardized SCSI Standard 5MHz and Fast 10MHzStandard 5MHz and Fast 10MHz Standard 8-bit width (standard or narrow)Standard 8-bit width (standard or narrow) Wide 16-bit width Wide 16-bit width Wide 32-bit width, never commercially Wide 32-bit width, never commercially

successfulsuccessful

SCSI-3: Ultra SCSISCSI-3: Ultra SCSI

Fast-20: The originalFast-20: The original Ultra SCSI (8-bit, 20MBps)Ultra SCSI (8-bit, 20MBps) Ultra Wide (16-bit, 40MBps)Ultra Wide (16-bit, 40MBps)

Fast-40Fast-40 Ultra2 (8-bit, 40MBps)Ultra2 (8-bit, 40MBps) Ultra2 Wide (16-bit, 80MBps)Ultra2 Wide (16-bit, 80MBps)

SCSI-3: Ultra SCSI (continued)SCSI-3: Ultra SCSI (continued)

Fast-80DT Fast-80DT (a.k.a. Ultra3, Ultra160, Ultra160+)(a.k.a. Ultra3, Ultra160, Ultra160+) 16-bit width16-bit width Data transfer up to 160MBpsData transfer up to 160MBps

Fast-160DTFast-160DT(a.k.a. Ultra4, Ultra320)(a.k.a. Ultra4, Ultra320) 16-bit width16-bit width Data transfer up to 320MBpsData transfer up to 320MBps

SCSI IDsSCSI IDs

Each device has its own ID numberEach device has its own ID number On narrow SCSI (8-bit), 0 through 7On narrow SCSI (8-bit), 0 through 7 On wide SCSI (16-bit), 0 through 15On wide SCSI (16-bit), 0 through 15

SCSI ID set with jumper or switch on SCSI ID set with jumper or switch on board, or in board’s built-in Setup utilityboard, or in board’s built-in Setup utility

Plug-and-Play SCSI ID assignment Plug-and-Play SCSI ID assignment available on most modern equipmentavailable on most modern equipment

Setting SCSI JumpersSetting SCSI Jumpers

Set ID numbers with binary system of Set ID numbers with binary system of numberingnumbering

Pins numbered right to left (usually)Pins numbered right to left (usually) On example below, ID is set to 5 (4 + 1)On example below, ID is set to 5 (4 + 1)

SCSI TerminationSCSI Termination

Both ends of SCSI chain must be Both ends of SCSI chain must be terminatedterminated

If chain ends at adapter on one end, If chain ends at adapter on one end, jumper on adapter typically usedjumper on adapter typically used

Terminator can be internal or externalTerminator can be internal or external Terminator can be active or passiveTerminator can be active or passive

SCSI TerminationSCSI Termination

Passive termination: Uses resistors to Passive termination: Uses resistors to block the signal block the signal

Active termination: Uses voltage Active termination: Uses voltage regulators to block the signal. Much more regulators to block the signal. Much more effective.effective.

SCSI TerminationSCSI Termination

Built-in versus separateBuilt-in versus separate Some SCSI devices have jumpers for built-in Some SCSI devices have jumpers for built-in

terminationtermination A separate block can be attached for separate A separate block can be attached for separate

terminationtermination

SCSI TerminationSCSI Termination

Internal vs. externalInternal vs. external Internal terminator terminates an internal Internal terminator terminates an internal

SCSI chain (inside PC case)SCSI chain (inside PC case) External terminator terminates an external External terminator terminates an external

SCSI chain (outside PC case)SCSI chain (outside PC case)

More Ways to Categorize SCSI More Ways to Categorize SCSI

Single-Ended: Standard (SE)Single-Ended: Standard (SE) Low-Voltage Differential (LVD)Low-Voltage Differential (LVD)

Greater speeds, more devices, Greater speeds, more devices, greater distance for chaingreater distance for chain

All devices must support LVD, All devices must support LVD, and must use LVD termination; and must use LVD termination; otherwise devices revert to SE otherwise devices revert to SE performanceperformance

More Ways to Categorize SCSIMore Ways to Categorize SCSI

High-Voltage Differential High-Voltage Differential (HVD)(HVD) Incompatible with SE and LVDIncompatible with SE and LVD Allows greater maximum Allows greater maximum

distancesdistances Cannot be combined with any Cannot be combined with any

other SCSI devices on a chainother SCSI devices on a chain Must use HVD terminationMust use HVD termination

Prepare a DrivePrepare a Drive

Floppy: nothing requiredFloppy: nothing required IDE: Set master/slave jumpersIDE: Set master/slave jumpers SCSI: Set SCSI ID jumpers and SCSI: Set SCSI ID jumpers and

termination if requiredtermination if required

Mount the Drive in the Bay Mount the Drive in the Bay (Internal)(Internal)

Mount the Drive in the Bay Mount the Drive in the Bay (External)(External)

Install the SCSI AdapterInstall the SCSI Adapter

SCSI onlySCSI only Set jumper on adapter for ID and Set jumper on adapter for ID and

termination if requiredtermination if required Install in PCI expansion slotInstall in PCI expansion slot

Connect Drive to Motherboard or Connect Drive to Motherboard or AdapterAdapter

Red Stripe goes to Pin 1Red Stripe goes to Pin 1 Cable might be keyed to match notch in Cable might be keyed to match notch in

motherboard slotmotherboard slot

Connect Ribbon Cable to DriveConnect Ribbon Cable to Drive

Connect Power Supply to DriveConnect Power Supply to Drive

Mini connector for floppy drivesMini connector for floppy drives Molex connector for all other drivesMolex connector for all other drives

BIOS ConfigurationBIOS Configuration

Usually Plug-and-Play, no configuration Usually Plug-and-Play, no configuration needed (except floppy drive)needed (except floppy drive)

BIOS Setup will see drive immediately if BIOS Setup will see drive immediately if attached directly to motherboardattached directly to motherboard Primary master, primary slave, secondary Primary master, primary slave, secondary

master, secondary slavemaster, secondary slave Drive must be partitioned before OS will Drive must be partitioned before OS will

see itsee it

Troubleshooting Dead DriveTroubleshooting Dead Drive

Snug all cablesSnug all cables Check jumper settingsCheck jumper settings Check for Pin 1 cable orientationCheck for Pin 1 cable orientation Check BIOS setup to make sure interface Check BIOS setup to make sure interface

is enabledis enabled Try a different power supply connectorTry a different power supply connector Try a different ribbon cableTry a different ribbon cable

Other Common ProblemsOther Common Problems

Floppy light remains onFloppy light remains on Ribbon cable is backwardsRibbon cable is backwards

Drive content does not refresh (floppy)Drive content does not refresh (floppy) Broken wire #34 on floppy drive cableBroken wire #34 on floppy drive cable

OS does not see driveOS does not see drive Drive not partitioned yetDrive not partitioned yet