Maxtor 51536H2 Bedienungsanleitung

Hard Disk Drive Specifications Models: 546106, 53073H4, 52049H3, 51536H2 This publication could include technical inaccuracies or typographical errors. Changes are periodically made to the information herein – which will be incorporated in revised editions of the publication. Maxtor may make changes or improvements in the product(s) described in [...]

Revisions Manual No. 1493 RE V E C N O . S E C TIO N DE S C RIP TIO N D ATE A 8034 5 Al l In it ial rel ea se. 7/1 9/200 0[...]

Before Y Before Y Before Y Before Y Before Y ou Begin ou Begin ou Begin ou Begin ou Begin Thank you for your interest in Maxtor hard disk drives. This manual provides technical information for OEM engineers and systems integrators regarding the installation and use of Maxtor hard drives. Drive repair should be performed only at an authorized repair[...]

i Contents Contents Contents Contents Contents Section 1 Section 1 Section 1 Section 1 Section 1 — Introduction Introduction Introduction Introduction Introduction Maxtor Corporation 1 - 1 Products 1 - 1 Support 1 - 1 Manual Organization 1 - 1 Abbreviations 1 - 1 Conventions 1 - 2 Key Words 1 - 2 Numbering 1 - 2 Signal Conventions 1 - 2 Section 2[...]

ii Section 3 Section 3 Section 3 Section 3 Section 3 — Product Specifications Product Specifications Product Specifications Product Specifications Product Specifications Models and Capacities 3 - 1 Drive Configuration 3 - 1 Performance Specifications 3 - 1 Physical Dimensions 3 - 2 Power Requirements 3 - 3 Power Mode Definitions 3 - 3 Spin-up 3 -[...]

iii Section 5 Section 5 Section 5 Section 5 Section 5 — AT Interface Description AT Interface Description AT Interface Description AT Interface Description AT Interface Description Interface Connector 5 - 1 Pin Description Summary 5 - 1 Pin Description Table 5 - 2 PIO Timing 5 - 3 DMA Timing 5 - 4 Ultra DMA Timing Parameters 5 - 5 Section 6 Secti[...]

iv Write Verify Sector(s) 7 - 4 Write Sector Buffer 7 - 4 Write DMA 7 - 5 Write Multiple 7 - 5 Mode Set/Check Commands 7 - 6 Set Features Mode 7 - 6 Read Native Max Address 7 - 7 Set Max 7 - 7 Set Max Password 7 - 7 Set Max Lock 7 - 7 Set Max Unlock 7 - 7 Set Max Freeze Lock 7 - 7 Power Mode Commands 7 - 8 Standby Immediate 7 - 8 Idle Immediate 7 -[...]

v Figures Figures Figures Figures Figures Figure T itle Page 2 - 1 PCBA Jumper Location and Configuration 2 - 6 3 - 1 Outline and Mounting Dimensions 3 - 2 4 - 1 Multi-pack Shipping Container 4 - 2 4 - 2 Single-pack Shipping Container (Option A) 4 - 3 4 - 3 Single-pack Shipping Container (Option B) 4 - 3 4 - 4 IDE Interface and Power Cabling Detail[...]

INTRODUCTION 1 – 1 SECTION 1 Introduction Introduction Introduction Introduction Introduction Maxtor Corporation Maxtor Corporation Maxtor Corporation Maxtor Corporation Maxtor Corporation Maxtor Corporation has been providing high-quality computer storage products since 1982. Along the way, we’ve seen many changes in data storage needs. Not lo[...]

INTRODUCTION 1 – 2 Conventions Conventions Conventions Conventions Conventions If there is a conflict between text and tables, the table shall be accepted as being correct. Key Words Key Words Key Words Key Words Key Words The names of abbreviations, commands, fields and acronyms used as signal names are in all uppercase type (e.g., IDENTIFY DRIV[...]

PRODUCT DESCRIPTION 2 – 1 SECTION 2 Product Product Product Product Product Description Description Description Description Description Maxtor hard disk drives are 1-inch high, 3.5-inch diameter random access storage devices which incorporate an on-board Ultra ATA/100 controller. High capacity is achieved by a balanced combination of high areal r[...]

PRODUCT DESCRIPTION 2 – 2 Product Product Product Product Product Features Features Features Features Features Functional / Interface Functional / Interface Functional / Interface Functional / Interface Functional / Interface Maxtor hard drives contain all necessary mechanical and electronic parts to interpret control signals and commands from an[...]

PRODUCT DESCRIPTION 2 – 3 Defect Management Zone (DMZ) Defect Management Zone (DMZ) Defect Management Zone (DMZ) Defect Management Zone (DMZ) Defect Management Zone (DMZ) Each drive model has a fixed number of spare sectors per drive, all of which are located at the end of the drive. Upon detection of a bad sector that has been reassigned, the ne[...]

PRODUCT DESCRIPTION 2 – 4 Major HDA Components Major HDA Components Major HDA Components Major HDA Components Major HDA Components Drive Mechanism Drive Mechanism Drive Mechanism Drive Mechanism Drive Mechanism A brush-less DC direct drive motor rotates the spindle at 7200 RPM (±0.1%). The dynamically balanced motor/spindle assembly ensures mini[...]

PRODUCT DESCRIPTION 2 – 5 JU M PE R C O N F I G U R A T I O N J50 J48 J46 J44 J42 M a st e r/S l a ve On l y dr iv e in s in g le d r i v e s y st em * M a s t er dr i v e in dual dri v e s y st em * S l av e dri v e in d ua l dr i v e s y st em C C O Ca b l e Se l e c t Di s abl e d* E n a b l e d O C C y l ind er L i m it at i on Di s abl e d* [...]

PRODUCT SPECIFICATIONS 3 – 1 SECTION 3 Product Specifications Product Specifications Product Specifications Product Specifications Product Specifications Models and Capacities Models and Capacities Models and Capacities Models and Capacities Models and Capacities Performance Specifications Performance Specifications Performance Specifications Per[...]

PRODUCT SPECIFICATIONS 3 – 2 Physical Dimensions Physical Dimensions Physical Dimensions Physical Dimensions Physical Dimensions (maximum) Figure 3 - 1 Outline and Mounting Dimensions P ARAM E TE R S TAN D ARD ME T R IC H eig h t 1.028 in c hes 26.1 m i l li m eters Length 5.787 in c hes 147 mil l imet er s W idth 4.02 in ches 1 02.1 m il l imet [...]

PRODUCT SPECIFICATIONS 3 – 3 Power Requirements Power Requirements Power Requirements Power Requirements Power Requirements Power Mode Definitions Power Mode Definitions Power Mode Definitions Power Mode Definitions Power Mode Definitions Spin-up Spin-up Spin-up Spin-up Spin-up The drive is spinning up following initial application of power and h[...]

PRODUCT SPECIFICATIONS 3 – 4 Reliability Specifications Reliability Specifications Reliability Specifications Reliability Specifications Reliability Specifications Annual Return Rate Annual Return Rate Annual Return Rate Annual Return Rate Annual Return Rate < 1.0% Annual Return Rate (ARR) indicates the average against products shipped. ARR in[...]

PRODUCT SPECIFICATIONS 3 – 5 EMC/EMI EMC/EMI EMC/EMI EMC/EMI EMC/EMI Radiated Electromagnetic Field Emissions - EMC Compliance Radiated Electromagnetic Field Emissions - EMC Compliance Radiated Electromagnetic Field Emissions - EMC Compliance Radiated Electromagnetic Field Emissions - EMC Compliance Radiated Electromagnetic Field Emissions - EMC [...]

INSTALLATION 4 – 1 SECTION 4 Handling and Installation Handling and Installation Handling and Installation Handling and Installation Handling and Installation Hard Drive Handling Precautions Hard Drive Handling Precautions Hard Drive Handling Precautions Hard Drive Handling Precautions Hard Drive Handling Precautions ◆ If the handling precautio[...]

INSTALLATION 4 – 2 Unpacking and Inspection Unpacking and Inspection Unpacking and Inspection Unpacking and Inspection Unpacking and Inspection Retain any packing material for reuse. Inspect the shipping container for evidence of damage in transit. Notify the carrier immediately in case of damage to the shipping container. As they are removed, in[...]

INSTALLATION 4 – 3 Figure 4 - 2 Single Pack Shipping Container (Option A) Figure 4 - 3 Single Pack Shipping Container (Option B) Repacking Repacking Repacking Repacking Repacking If a Maxtor drive requires return, repack it using Maxtor packing materials, including the antistatic bag. Physical Installation Physical Installation Physical Installat[...]

INSTALLATION 4 – 4 Before You Begin Before You Begin Before You Begin Before You Begin Before You Begin Important – Please Read Important – Please Read Important – Please Read Important – Please Read Important – Please Read Please read this installation section completely before installing the Maxtor hard drive. It gives general informa[...]

INSTALLATION 4 – 5 Install the Hard Drive in a Device Bay Install the Hard Drive in a Device Bay Install the Hard Drive in a Device Bay Install the Hard Drive in a Device Bay Install the Hard Drive in a Device Bay Refer to your computer user’s manual for specific mounting information. Be sure to secure the drive to the device bay with all four [...]

AT INTERFACE DESCRIPTION 5 – 1 SECTION 5 A A A A A T Interface Description T Interface Description T Interface Description T Interface Description T Interface Description Interface Connector Interface Connector Interface Connector Interface Connector Interface Connector All Maxtor hard drives have a 40-pin ATA interface connector mounted on the P[...]

AT INTERFACE DESCRIPTION 5 – 2 Pin Description Table Pin Description Table Pin Description Table Pin Description Table Pin Description Table P IN NAME P IN I/ O S IG NAL NAME S I G NAL DE S C RIPTIO N R ESET - 0 1 I Ho s t R e s et R es et sign al fr om th e h ost s y s t em. Act iv e du r in g powe r u p an d in act i v e aft e r . DD0 1 7 I /O [...]

AT INTERFACE DESCRIPTION 5 – 3 T I M I N G P AR A METE R S M OD E 0 MOD E 1 M OD E 2 M OD E 3 MOD E 4 t 0 C y c le Ti m e ( min ) 6 0 0 ns 3 8 3 ns 2 4 0 ns 1 8 0 ns 1 2 0 ns t1 A ddr es s v al id to D IO R - /D I O W - set u p (m i n) 70 n s 50 n s 30 n s 30 n s 25 n s t 2 D I OR - / D IO W - 16 - bi t ( min ) 1 6 5 ns 1 2 5 ns 1 0 0 ns 8 0 ns 7[...]

AT INTERFACE DESCRIPTION 5 – 4 DMA Timing DMA Timing DMA Timing DMA Timing DMA Timing T IMI N G P ARAME T E RS MO DE 0 MO DE 1 MO DE 2 t0 Cy cl e T ime (mi n) 480 n s 150 n s 120 n s tC D MAC K to DM A RQ d ela y tD D I OR - /D I O W- (mi n) 215 n s 80 n s 70 n s tE DI O R- d a ta a cce ss ( min ) 1 5 0 n s 6 0 n s t F D I OR - d at a h o ld ( m [...]

AT INTERFACE DESCRIPTION 5 – 5 Ultra DMA Timing Ultra DMA Timing Ultra DMA Timing Ultra DMA Timing Ultra DMA Timing T I M I N G P ARAME T E RS ( all t i m es in nan osec o nd s ) M OD E 0 M ODE 1 M OD E 2 M OD E 3 M OD E 4 M ODE 5 MI N MA X MI N MA X MI N MA X MI N MA X MI N MA X MI N MA X t CY C C y cl e T i me (from STR O B E ed g e to ST RO BE[...]

AT INTERFACE DESCRIPTION 5 – 6 Figure 5 - 5 Sustained Ultra DMA Data In Burst t DVH DSTROBE at d evice DD(15:0) at d evice DSTROBE at host DD(15:0) at host t DVH t CYC t CYC t DVS t DVS t DH t DS t DH t DS t 2CYC t DH t DVH t 2CYC DMARQ (device) DMACK- (host) STOP (host) HDMARDY- (host) DSTROBE (device) DD(15:0) (device) t SR t RFS t RP Figure 5 [...]

AT INTERFACE DESCRIPTION 5 – 7 t AZ t IORDYZ CRC DMARQ ( device ) DMACK- (host) STOP (host) HDMARDY- (host) DSTROBE ( device ) DD(15:0) DA0, DA1 , DA2, CS0-, CS1- t ACK t LI t MLI t DVS t LI t ACK t ACK t ZAH t DVH t SS t LI Figure 5 - 7 Device Terminating an Ultra DMA Data In Burst t DVH CRC t AZ DMARQ (device) DMACK- (host) STOP ( host ) HDMARD[...]

AT INTERFACE DESCRIPTION 5 – 8 t DH t DS t DVH HSTROBE at host DD(15:0) at host HSTROBE at d evice DD(15:0) at d evice t DVH t CYC t CYC t DVS t DVS t DS t DH t 2CYC t DH t DVH t 2CYC DMARQ (device) DMACK- ( host ) STOP (host) DDMARDY- (device) HSTROBE (host) DD(15:0) (host) DA0, DA1 , DA2, CS0-, CS1- t UI t ACK t ENV t ZIORDY t LI t DVS t DVH t [...]

AT INTERFACE DESCRIPTION 5 – 9 DMARQ (device) DMACK- (host) STOP (host) DDMARDY- (device) HSTROBE (host) DD(15:0) (host) t SR t RFS t RP Figure 5 - 11 Device Pausing an Ultra DMA Data Out Burst DMARQ (device) DMACK- (host) STOP (host) DDMARDY- (device) HSTROBE (host) DD(15:0) (host) DA0, DA1 , DA2, CS0-, CS1- t ACK t LI t MLI t DVS t LI t LI t AC[...]

AT INTERFACE DESCRIPTION 5 – 10 DMARQ (device) DMACK- (host) STOP ( host ) DDMARDY- ( device ) HSTROBE (host) DD(15:0) (host) DA0, DA1 , DA2, CS0- , CS1- t ACK t MLI t DVS t LI t LI t ACK CRC t DVH t ACK t IORDYZ t MLI t RP t RFS Figure 5 - 13 Device Terminating an Ultra DMA Data Out Burst[...]

HOST SOFTWARE INTERFACE 6 – 1 SECTION 6 Host Software Interface Host Software Interface Host Software Interface Host Software Interface Host Software Interface The host communicates with the drive through a set of controller registers accessed via the host’s I/O ports. These registers divide into two groups: the Task File, used for passing comm[...]

HOST SOFTWARE INTERFACE 6 – 2 Sector Count Register Sector Count Register Sector Count Register Sector Count Register Sector Count Register Holds the number of sectors to be sent during a Read or Write command, and the number of sectors per track during a Format command. A value of zero in this register implies a transfer of 256 sectors. A multi-[...]

HOST SOFTWARE INTERFACE 6 – 3 Command Register Command Register Command Register Command Register Command Register Contains code for the command to be performed. Additional command information should be written to the task file before the Command register is loaded. When this register is written, the BUSY bit in the Status register sets, and inte[...]

HOST SOFTWARE INTERFACE 6 – 4 C O M M A ND N A M E C O M M AN D C O D E PAR AM E T E R S U S E D b7 b6 b5 b4 b3 b2 b1 b0 F S C S N C S D H R e c a l i b r a t e 0 0 0 1 xxxx N N N N D Re ad S ec t or ( s ) 0 0 1 0 0 0 L x N Y Y Y Y Re a d D MA 1 1 0 0 1 0 0 x N Y Y Y Y Wri t e S ec t or ( s ) 0 0 1 1 0 0 L x N Y Y Y Y W r i t e D M A 1 1 0 01 01 [...]

HOST SOFTWARE INTERFACE 6 – 5 Control Diagnostic Registers Control Diagnostic Registers Control Diagnostic Registers Control Diagnostic Registers Control Diagnostic Registers These I/O port addresses reference three Control/Diagnostic registers: I/O P O R T R E AD WR ITE 3F 6h Al te r n a t e Stat u s Fi x ed D isk C on tr ol 3F 7h D i gi tal I n[...]

HOST SOFTWARE INTERFACE 6 – 6 Reset and Interrupt Handling Reset and Interrupt Handling Reset and Interrupt Handling Reset and Interrupt Handling Reset and Interrupt Handling Reset Handling Reset Handling Reset Handling Reset Handling Reset Handling One of three different conditions may cause a reset: power on, hardware reset or software reset. A[...]

INTERFACE COMMANDS 7 – 1 SECTION 7 Interface Commands Interface Commands Interface Commands Interface Commands Interface Commands The following section describes the commands (and any parameters necessary to execute them), as well as Status and Error register bits affected. Read Commands Read Commands Read Commands Read Commands Read Commands Rea[...]

INTERFACE COMMANDS 7 – 2 Read Commands Read Commands Read Commands Read Commands Read Commands Read Sector(s) Read Sector(s) Read Sector(s) Read Sector(s) Read Sector(s) Reads from 1 to 256 sectors, as specified in the Command Block, beginning at the specified sector. (A sector count of 0 requests 256 sectors.) Immediately after the Command regis[...]

INTERFACE COMMANDS 7 – 3 Read DMA Read DMA Read DMA Read DMA Read DMA Multi-word DMA Identical to the Read Sector(s) command, except that 1 . The host initializes a slave-DMA channel prior to issuing the command, 2 . Data transfers are qualified by DMARQ and are performed by the slave-DMA channel and 3 . The drive issues only one interrupt per co[...]

INTERFACE COMMANDS 7 – 4 Set Multiple Mode Set Multiple Mode Set Multiple Mode Set Multiple Mode Set Multiple Mode Enables the controller to perform Read and Write Multiple operations, and establishes the block count for these commands. Before issuing this command, the Sector Count register should be loaded with the number of sectors per block. T[...]

INTERFACE COMMANDS 7 – 5 Write Multiple Write Multiple Write Multiple Write Multiple Write Multiple Performs similarly to the Write Sector(s) command, except that: 1 . The controller sets BSY immediately upon receipt of the command, 2 . Data transfers are multiple sector blocks and 3 . The Long bit and Retry bit is not valid. Command execution di[...]

INTERFACE COMMANDS 7 – 6 Mode Set/Check Commands Mode Set/Check Commands Mode Set/Check Commands Mode Set/Check Commands Mode Set/Check Commands Set Features Mode Set Features Mode Set Features Mode Set Features Mode Set Features Mode Enables or disables features supported by the drive. When the drive receives this command it: 1 . Sets BSY, 2 . C[...]

INTERFACE COMMANDS 7 – 7 Read Native Max Address Read Native Max Address Read Native Max Address Read Native Max Address Read Native Max Address This command returns the native maximum address. The native maximum address is the highest address accepted by the drive in the factory default condition. The native maximum address is the maximum addres[...]

INTERFACE COMMANDS 7 – 8 Power Mode Commands Power Mode Commands Power Mode Commands Power Mode Commands Power Mode Commands Standby Immediate – 94h/E0h Standby Immediate – 94h/E0h Standby Immediate – 94h/E0h Standby Immediate – 94h/E0h Standby Immediate – 94h/E0h Spin down and do not change time out value. This command will spin the dr[...]

INTERFACE COMMANDS 7 – 9 Default Power-on Condition Default Power-on Condition Default Power-on Condition Default Power-on Condition Default Power-on Condition The drive’s default power on condition is the ACTIVE MODE. Upon receiving a Power Mode command, except the SLEEP MODE command, the drive sets BSY and performs the requested power operati[...]

INTERFACE COMMANDS 7 – 10 Initialization Commands Initialization Commands Initialization Commands Initialization Commands Initialization Commands Identify Drive Identify Drive Identify Drive Identify Drive Identify Drive Allows the host to receive parameter information from the drive. When the command is received, the drive: 1 . Sets BSY, 2 . Sto[...]

INTERFACE COMMANDS 7 – 11 - W O R D C ON T EN T D ESC R IPT I ON 50 R e s e r v ed 51 - 5 2 Obsol e te 53 15 -3 = re s e rv ed 2, 1 = t h e fie l ds s u pp or t ed in w or d s 8 8 ar e v al i d , 0 = t he f ie l d s s up por t ed in wor ds 88 ar e n ot va l i d 1, 1 = t h e f i el ds re po r ts i n w o rd s 64 - 70 a re v al i d, 0 = th e f i el [...]

INTERFACE COMMANDS 7 – 12 W O R D CONT E NT DE S C RIP TIO N 83 C o m m a nd s e t s s upp o rt e d . If w o rd s 8 2 a nd 8 3 = 00 0 0 h o r F F F Fh c o m m a nd s e t no t i f i c a t i o n no t s up p or t ed . 15 - 1 0, as c u r re n tl y defi ne d 9 , 1 = A ut o m a ti c A c o us t ic M a na ge m e nt f e atur e se t s u p p or t ed 8- 0, a[...]

INTERFACE COMMANDS 7 – 13 Initialize Drive Parameters Initialize Drive Parameters Initialize Drive Parameters Initialize Drive Parameters Initialize Drive Parameters Enables the drive to operate as any logical drive type. The drive will always be in the translate mode because of Zone Density Recording, which varies the number of sectors per track[...]

INTERFACE COMMANDS 7 – 14 Seek, Format and Diagnostic Commands Seek, Format and Diagnostic Commands Seek, Format and Diagnostic Commands Seek, Format and Diagnostic Commands Seek, Format and Diagnostic Commands Seek Seek Seek Seek Seek Initiates a seek to the track, and selects the head specified in the Command block. 1 . Sets BSY in the Status r[...]

INTERFACE COMMANDS 7 – 15 S.M.A.R.T. Command Set S.M.A.R.T. Command Set S.M.A.R.T. Command Set S.M.A.R.T. Command Set S.M.A.R.T. Command Set Execute S.M.A.R.T. Execute S.M.A.R.T. Execute S.M.A.R.T. Execute S.M.A.R.T. Execute S.M.A.R.T. The Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.) command has been implemented to improve the d[...]

SERVICE AND SUPPORT 8 – 1 SECTION 8 Service and Support Service and Support Service and Support Service and Support Service and Support Service Policy Service Policy Service Policy Service Policy Service Policy If a customer discovers a defect in a Maxtor hard drive, Maxtor will, at its option, repair or replace the disk drive at no charge to the[...]

SERVICE AND SUPPORT 8 – 2 MaxFax MaxFax MaxFax MaxFax MaxFax ® ® ® ® ® Service Service Service Service Service Use a touch-tone phone to order Technical Reference Sheets, Drive Specifications, Installation Guides and other documents from our 24-hour automated fax retrieval system. Requested items are sent directly to your fax machine. U.S. a[...]

GLOSSARY GL – 1 GLOSSAR Y Glossary Glossary Glossary Glossary Glossary A A A A A ACCESS ACCESS ACCESS ACCESS ACCESS To obtain data from, or place data into, RAM, a register, or data storage device. ACCESS TIME ACCESS TIME ACCESS TIME ACCESS TIME ACCESS TIME The interval between the issuing of an access command and the instant that the target data[...]

GLOSSARY GL – 2 CONTROLLER CONTROLLER CONTROLLER CONTROLLER CONTROLLER A miniature CPU dedicated to controlling a peripheral device, such as a disk drive, tape drive, video display terminal, or printer. The controller executes commands from the central processing unit and reissues commands to the peripheral device. CORRECTABLE ERROR CORRECTABLE E[...]

GLOSSARY GL – 3 EXTRA PULSE EXTRA PULSE EXTRA PULSE EXTRA PULSE EXTRA PULSE Term used in surface certification. It is when a flux field discontinuity remains after the recording surface is erased, thereby producing an electrical output of a read head passing over the area with the discontinuity. An extra pulse occurs when the electrical output is[...]

GLOSSARY GL – 4 L L L L L LANDING ZONE OR LZONE LANDING ZONE OR LZONE LANDING ZONE OR LZONE LANDING ZONE OR LZONE LANDING ZONE OR LZONE The cylinder number to where ParkHeads move the read/write heads. LATE BIT LATE BIT LATE BIT LATE BIT LATE BIT A bit that is in the late half of the data window. LATE WINDOW LATE WINDOW LATE WINDOW LATE WINDOW LA[...]

GLOSSARY GL – 5 PHASE MARGIN PHASE MARGIN PHASE MARGIN PHASE MARGIN PHASE MARGIN Measure in degrees of the amount of difference between excursions from the window center where flux reversals can occur and the edge of the data window. Similar to window margin. PHYSICAL SECTOR PHYSICAL SECTOR PHYSICAL SECTOR PHYSICAL SECTOR PHYSICAL SECTOR The smal[...]

GLOSSARY GL – 6 SOFT ERROR SOFT ERROR SOFT ERROR SOFT ERROR SOFT ERROR A data error which can be overcome by rereading the data or repositioning the head. SOFT SECTORED SOFT SECTORED SOFT SECTORED SOFT SECTORED SOFT SECTORED A technique where the controller determines the beginning of a sector by the reading of format information from the disk. T[...]