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25 WRITE (0Ah) 25-125.1AboutThisCommand ... 25-225.2FieldDefinitions... 25-225.3TapePosi

Notes:3-38EXB-8205 and EXB-8505(Standard and XL)5105033 Implementing CTS Operations

4ERASE (19h)BitByte76543210000001100101 Logical Unit Number Reserved Immed Long02Reserved030405 Vendor Unique Reserved 0 0May 1994 EXB-8205 and EXB-85

4.1 About This CommandThe ERASE command causes the CTS to erase all tape from thecurrent valid tape position to the physical end of tape (PEOT). Whent

4.2 Field DefinitionsByte 01, Bit 1 - ImmedThe Immed bit is used to determine when command status isreturned to the initiator, as follows:0 – Status i

4.3 Tape PositioningTable 4-1 shows the legal tape positions for an erase operation in thedata formats supported by the EXB-8505 and EXB-8205.When era

5INQUIRY (12h)BitByte76543210000001001001 Logical Unit Number Reserved EVPD02 Page Code03 Reserved04 Allocation Length05 Vendor Unique Reserved 0 0May

5.1 About This CommandThe INQUIRY command requests that information about the CTS’sparameters be sent to the initiator. The CTS executes the INQUIRYco

Byte 04 - Allocation LengthThe Allocation Length specifies the number of bytes that the initiatorhas allocated for the return of inquiry data. A value

5.3 Standard Inquiry DataThe CTS returns the Standard Inquiry Data when the EVPD bit in theCDB is 0.BitByte7654321000 Peripheral Qualifier Peripheral

Byte 00, Bits 7 through 5 - Peripheral QualifierThis field, in combination with the Peripheral Device Type field (byte00, bits 4 through 0), identifie

Appendix D SCSI Bus Message Processing and Error Recovery D-1SCSI Bus Error Recovery (Initiators Supporting the Command CompleteMessageOnly)...

Byte 03, Bit 6 - TrmIOPThe value returned for this field is 0, which indicates that the CTSdoes not support the Terminate I/O Process message.Byte 03,

Byte 07, Bit 0 - SftReThe value returned for this field is 0, which indicates that the CTSdoes not support the soft reset alternative in response to a

5.4 Supported Vital Product Data PageThe CTS returns the Supported Vital Product Data page when theEVPD bit in the CDB is 1 and the Page Code is 0.Bit

5.5 Unit Serial Number PageThe CTS returns the Unit Serial Number page when the EVPD bit intheCDBis1andthePageCodeis80h.BitByte7654321000 Device Type

Notes:5-10EXB-8205 and EXB-8505(Standard and XL)5105035 INQUIRY (12h)

6LOAD/UNLOAD (1Bh)BitByte76543210000001101101 Logical Unit Number Reserved Immed02Reserved0304 Reserved EOT Re-Ten Load05 Vendor Unique Reserved 0 0Ma

6.1 About This CommandThe LOAD/UNLOAD command causes the CTS to load or unloadthe data cartridge.Loading a Data CartridgeWhen loading a data cartridge

Using the LOAD/UNLOAD Command on a Partitioned TapeWhen the tape you are using is formatted with two partitions (seeSection 3.7), the LOAD/UNLOAD comm

6.2 Field DefinitionsByte 01, Bit 1 - ImmedThe Immed bit is used to determine when command status isreturned to the initiator, as follows:0 – Status i

Byte 04, Bit 0 - LoadThe Load bit indicates which operation, load or unload, is to beperformed as follows:0 – Perform an unload operation.1 – Perform

FiguresCTS FeaturesFigure 1-1 EXB-8505 (top) and EXB-8205 (bottom) . . . . . . . . . . . . . . . . . . . . 1-2Figure 1-2 Relationship of 8mm physical

Notes:6-6EXB-8205 and EXB-8505(Standard and XL)5105036 LOAD/UNLOAD (1Bh)

7LOCATE (2Bh)BitByte76543210000010101101 Logical Unit Number Reserved BT CP Immed02 Reserved03 (MSB)Block Address…06 (LSB)07 Reserved08 Partition09 AD

7.1 About This CommandThe LOCATE command, in conjunction with the READ POSITION(34h) command, allows you to position the tape at a specified logicalbl

Notes:The LOCATE command is not supported for tapes written in 8200format and will result in Check Condition status. The sense keywill be set to Illeg

7.2 Field DefinitionsByte 01, Bit 2 - BT (Block Type)TheBTbitdeterminesthetypeofblocknumbercontainedintheBlock Address field (bytes 03 through 06), as

If the CTS buffer contains data from a previous WRITE command andthe LOCATE command is in the reverse direction, the CTSdisconnects from the initiator

Byte 09, Bit 7 - ADE (Always Detect EOD)TheADEbitisusedonlyforthoseCTSsthatincludetheEEPROMimage for directory support (see the “Allow position past E

7.3 Exceptions and Error ConditionsThe following exceptions and error conditions can occur with theLOCATE command.EOD DetectedIf the CTS detects the e

PEOT or PEOP EncounteredDuring a locate operation, if the CTS encounters the physical end oftape (PEOT) or the physical end of partition (8500c format

Unrecoverable ErrorIf an unrecoverable media or hardware error occurs during the locateoperation, the CTS terminates the LOCATE command and returnsChe

Figure D-10 Message processing during the Data In phase of commandsotherthanREAD ... D-22Figure D-11 Messageprocessingduring

Notes:7-10EXB-8205 and EXB-8505(Standard and XL)5105037 LOCATE (2Bh)

8LOG SELECT (4Ch)BitByte76543210000100110001 Logical Unit Number Reserved PCR SP02 PC Reserved03Reserved…0607 (MSB)Parameter List Length08 (LSB)09 Ven

8.1 About This CommandThe LOG SELECT command allows you to manage the counters thatthe CTS maintains about its write and read error recovery operation

Figure 8-1 Relationship of log parameters and parameter lists to the LOG SELECT CDBMay 1994 EXB-8205 and EXB-8505(Standard and XL)8-38 LOG SELECT (4Ch

8.2 Field DefinitionsByte 01, Bit 1 – PCR (Parameter Code Reset)The PCR bit indicates whether you want to set some or all of thecounters, as follows:0

Byte 02, Bits 5 through 0; Bytes 03 through 06 – ReservedThese bits and bytes are reserved.Bytes 07 and 08 – Parameter List LengthThe Parameter List L

8.3 Parameter List HeaderThe Parameter List Header is sent during the Data Out phase beforethe log parameters. More than one Parameter List Header can

8.4 Log ParametersZero or more log parameters follow the Parameter List Header. Eachlog parameter includes four bytes of descriptive information follo

ParameterCodeCounter Name Description0002hTotal RewritesWriteErrorCounterPage. Contains the number of physicalblocks the CTS rewrote to the tape becau

Byte 02, Bit 7 – Disable Update (DU)The DU bit indicates whether updates to the current cumulative valueare enabled or disabled, as follows:0 – The CT

TablesCTS FeaturesTable 1-1 ComparisonofCTSfeatures ... 1-3Table 1-2 Read and write compatibility of Exabyte 8mm Cartridge Tape

Byte 02, Bit 4 – Enable Threshold Comparison (ETC)The ETC field indicates whether threshold comparisons for thecounter are enabled or disabled, as fol

Byte 03 – Parameter LengthThe Parameter Length field indicates the length of the threshold orcumulative value in bytes. For example, if the value requ

8.5 Exceptions and Error ConditionsThe following exceptions and error conditions can occur with theLOG SELECT command.Illegal Value in LOG SELECT Data

FSCSenseKeyASC ASCQ DescriptionCAh 6h 5Bh 01hUnit Attention. Threshold met. (Foradditional information about this error,look at the Log Parameter Page

Notes:8-14EXB-8205 and EXB-8505(Standard and XL)5105038 LOG SELECT (4Ch)

9LOG SENSE (4Dh)BitByte76543210000100110101 Logical Unit Number Reserved PPC SP02 PC Page Code03Reserved0405 (MSB)Parameter Pointer06 (LSB)07 (MSB)All

9.1 About This CommandThe LOG SENSE command enables you to retrieve statisticalinformation about the CTS’s read and write error recovery operations.Th

Byte 02, Bits 7 and 6 – PC (Page Control)The PC field indicates what type of parameter values you want theCTS to return. Valid values for this field a

Bytes 05 and 06 – Parameter PointerThe Parameter Pointer field indicates the Parameter Code of the firstcounter you want to be returned for the reques

9.3 Parameter List HeaderThe four-byte Parameter List Header precedes each of the LOGSENSE pages. It specifies a page code and indicates the total len

LOG SELECT (4Ch)Table 8-1 Valid combinations of values for the fields in the LOG SELECTCDB... 8-5Table 8-2 Paramete

9.4 Supported Log Pages Page(Page Code=00h)The Supported Log Pages page is returned when the Page Code in theCDB is 00h. Unlike other LOG SENSE pages,

9.5 Log Parameter Data Blocks(Page Codes=02h and 03h)When the Page Code is 02h or 03h, the CTS returns information aboutits log parameters (counters)

Byte 0, Bit 7 – DU (Disable Update)The value returned for the Disable Update field indicates whetherupdates to the current cumulative value for this c

Byte 02, Bits 3 and 2 – TMC (Threshold Met Criteria)The value returned for the TMC bit specifies the conditions underwhich the CTS will generate a Uni

Write Error Counters Page (Page Code=02h)When you specify 02h for the Page Code, the CTS returns informationabout the counters listed in Table 9-1.Par

Total Bytes ProcessedThe Total Bytes Processed counter contains the number of bytessuccessfully written to the tape. This counter only includes user d

Total Bytes ProcessedThe Total Bytes Processed counter contains the number of user databytes transferred to the initiator. Rewritten data is not count

10MODE SELECT (15h)andMODE SENSE (1Ah)This chapter describes the bit and byte settings for both the MODESELECT and MODE SENSE commands. It consists of

MODE SELECT (15h)BitByte76543210000001010101 Logical Unit Number PF Reserved SP02Reserved0304 Parameter List Length05 Vendor Unique Reserved 0 0MODE S

10.1 About These CommandsThe MODE SELECT command allows the initiator to specify medium,logical unit, and device parameters. The MODE SENSE commandena

SPACE (11h)Table 22-1 ValuesofCodefieldfortheSPACEcommand ... 22-3WRITE (0Ah)Table 25-1 Legal locations for appending data on a previously

10.2 Field Definitions for MODE SELECT CDBByte 01, Bit 4 - PF (Page Format)The PF bit indicates in which format the MODE SELECT parametersare specifie

Page Format For page format, the value of the Parameter List Lengthbyte depends on which combination of parameter pages is beingtransferred. Table 10-

Example 2 To transfer the Parameter List Header, the BlockDescriptor, and the Data Compression Page:1. Specify 1Ch for the Parameter List Length byte

Restrictions for Sending MODE SELECT Parameters:For non-page format, valid transfer lengths for thevendor-unique parameters are 0, 1, 2, 3, 4, and 5 b

10.3 Field Definitions for MODE SENSE CDBByte 01, Bit 3 - DBD (Disable Block Descriptor)The Disable Block Descriptor bit indicates whether the initiat

To return theparameters in...Specify thisPage Code...And this information will be returned...Non-page format 00ha1 to 5 bytes of vendor-unique paramet

Page Format For page format, the Allocation Length byte can containvalues ranging from 00h to FFh, depending on which parameter pageis being returned

Example 1 To return the Parameter List Header, the BlockDescriptor, and the Vendor Unique Parameters Page 1:1. SettheDBDbitto0.2. Set the Page Code to

Truncating Pages An EEPROM option enables you to choosewhether the Allocation Length is checked for values that wouldcause the Parameter List Header,

10.4 Parameter List Header for MODE SELECTBitByte7654321000Reserved0102 RSVD Buffered Mode Speed03 Block Descriptor LengthByte 02, Bits 6 through 4 -

SCSI Bus Message Processing and Error RecoveryTable D-1 ResponsestotheAttentionsignal...D-3Error InformationTable E-1 REQUESTSENSE

Byte 02, Bits 3 through 0 - SpeedThe CTS does not support any operations at different speeds. Alloperations have a defined speed that cannot be modifi

Byte 01 - Medium TypeThe value returned in the Medium Type byte represents the length oftape currently loaded in the CTS. The values that can be retur

Byte 02, Bits 6 through 4 - Buffered ModeIndicates whether the CTS buffers data during a write operation, asexplained on page 10-13. The values return

10.6 Block DescriptorBitByte7654321000 Density Code01 (MSB)Number of Blocks0203 (LSB)04 Reserved05 (MSB)Block Length0607 (LSB)Byte 00 - Density CodeIn

SpecifythisDensityCode...To writedata in thisformatNotes00hDefault format(error checkingsuppressed)Use this Density Code at LBOT if you want to write

As described in Table 10-9, the value reported for the Density Codefield by the MODE SENSE command depends on the most recentactivity.If the most rece

Bytes 01 through 03 - Number of BlocksIn the MODE SENSE data, this field indicates the total capacity of thetape in 1-KByte physical blocks (LBOT to L

10.7 Vendor-Unique Parameters(Non-Page Format)BitByte7654321000 CT RSVD ND RSVD NBE EBD PE NAL01 Reserved 112m02 Motion Threshold03 Reconnect Threshol

Byte 00, Bit 5 - ND (No Disconnect During Data Transfer)This bit is used to enable the CTS to disconnect from the initiatorduring the data transfer ph

Byte 00, Bit 1 - PE (Parity Enable)This bit is used to enable parity checking on the SCSI bus. When thisbit is set to 1, every byte received by the CT

xviii EXB-8205 and EXB-8505(Standard and XL)510503

Byte 03 - Reconnect ThresholdThe value in the Reconnect Threshold byte indicates the amount ofdata that must be in the buffer before the CTS reconnect

10.8 Read-Write Error Recovery Page(Page Code=01h)The Read-Write Error Recovery Page specifies error recoveryparameters used during read-write operati

Byte 02, Bit 0 - DCR (Disable Correction)The DCR bit is not supported by the CTS. The valid value is 0.Byte 03 - Read Retry CountThe Read Retry Count

Byte 08 - Write Retry CountThe Write Retry Count field specifies how many times the CTS shouldrewrite a physical block before an unrecoverable write e

10.9 Disconnect-Reconnect Page(Page Code=02h)The Disconnect-Reconnect Page specifies parameters for CTSdisconnects and reconnects during data transfer

Byte 02 - Buffer Full RatioThe Buffer Full Ratio represents the amount of data that must bepresent in the buffer during a buffered read operation befo

Bytes 06 and 07 - Disconnect Time LimitThe only value supported by the CTS for the Disconnect Time Limitfield is 0. This value cannot be changed.Note:

10.10 Control Mode Page (Page Code=0Ah)The Control Mode Page allows you to specify whether the CTSshould return Check Condition status when one of its

Byte 03, Bit 1 - QErr (Queue Error)The CTS does not support the Simple Queue Tag message, so this bitmust be 0.Byte 03, Bit 0 - DQue (Disable Queuing)

10.11 Data Compression Page(Page Code=0Fh)The Data Compression Page specifies parameters for the control ofdata compression.EXB-8505 For the EXB-8505,

About This ManualThis manual provides reference information for developing softwareto support applications for the EXABYTE®EXB-8505 or EXB-82058mm Car

EXB-8505 Only: Using the Data Compression Page for 8500cCompressed Format TapesFor the EXB-8505, if your driver uses page format and you arereading an

Byte 01 - Page LengthThe Page Length indicates the number of bytes in the DataCompression Page that follow this byte. The valid value is 0Eh.Byte 02,

EXB-8205 For the EXB-8205, the DCE bit settings indicate the following:0 – Data compression is disabled. The write density is set to 14h(8200 format).

Bytes 08 through 11 - Decompression AlgorithmThe Decompression Algorithm field indicates which decompressionalgorithm the CTS will use when decompress

Byte 00, Bits 5 through 0 - Page CodeThe Page Code identifies the page being transferred. The valid valueis 10h (Device Configuration Page).Byte 01 -

Byte 02, Bit 5 - CAF (Change Active Format)The CAF bit indicates that the active format is to be changed and touse the values in the Active Format fie

Byte 03 - Active PartitionEXB-8505 If you have set the CAP bit (byte 02, bit 6) to 1 to change the activepartition, the Active Partition byte indicate

Note: The Write Buffer Full Ratio and the Read Buffer Empty Ratioin the Device Configuration Page have the same function asthe Motion Threshold in the

If the RSmk bit is 1 and the EXB-8505 encounters a setmark, it returnsCheck Condition status with the sense key set to No Sense (0h). TheASC and ASQ f

Byte 10, Bit 4 - EEG (Enable EOD Generation)The EEG bit indicates that the CTS will generate an EOD mark. TheEEG bit is set to 1 in the MODE SENSE dat

CopyrightCopyright 1994 by Exabyte Corporation. All rights reserved. Thisitem and the information contained herein are the property ofExabyte Corporat

Appendix E lists the possible combinations of values for theAdditional Sense Code (ASC) and Additional Sense CodeQualifier (ASCQ) fields returned by t

10.13 Medium Partition Page (Page Code=11h)The Medium Partition Page enables you to format a tape containingone or two partitions (see Section 3.7 for

When you format a partitioned tape, keep the following rules in mind:Before formatting new partitions, you must position the tape atLBOT (if it is cur

For the long form, specify either 00h or 01h. Specify 00h to defineno additional partitions (that is, the tape will have only onepartition). Specify 0

Byte 04, Bit 5 - IDP (Initiator Defined Partitions)The IDP bit tells the EXB-8505 to format the first partition on the tapebased on the size provided

For thesecombinations...These results occur...FDP SDP IDPWhen you specify noadditional partitions(Additional PartitionsDefined = 00h)...When you speci

Byte 04, Bits 4 and 3 - PSUM (Partition Size Unit of Measure)If you set IDP (Initiator Defined Partitions) to 1 and are definingadditional partitions

Bytes 08 and 09 - Partition SizeThe Partition Size field specifies the size of the first partition on thetape when IDP = 1 and Additional Partitions D

10.14 Vendor Unique Parameters Page 1(Page Code=20h)BitByte7654321000 Reserved Page Code01 Page Length02 CT RSVD ND RSVD NBE EBD PE NAL03 RTF WTF RSVD

Byte 02, Bit 5 - NDThis bit indicates whether the CTS can disconnect from the initiatorduring the data transfer phase, as follows:0 – The CTS can disc

Byte 02, Bit 2 - EBD (Even Byte Disconnect)This bit is used to enable disconnects on even-byte boundaries, asfollows:0 – Disconnect on any byte.1 – Di

Related PublicationsThe following publications provide additional, related information.EXB-8205 and EXB-8505 8mm Cartridge Tape SubsystemsFor informat

Byte 03, Bits 7 through 5 - RTF (Read Tape Format)These bits are ignored by the CTS in the MODE SELECT command.They are returned by the MODE SENSE com

Byte 03, Bit 0 - 112mThe 112m bit works in conjunction with the CT bit (byte 02, bit 7) toindicate the size of the data cartridge that is expected to

10.15 Vendor Unique Parameters Page 2(Page Code=21h)BitByte7654321000 Reserved Page Code01 Page Length02 Reserved03 Reserved LPART WWR04Reserved05Byte

The EXB-8505 ignores this bit if you load a single-partition tape afterissuing this command.EXB-8205 The EXB-8205 does not support partitioned tapes.

10.16 Data Compression Status Page(Page Code=22h)The Data Compression Status Page is available as MODE SENSE dataonly. You can use the information ret

Bytes 03 through 07 - Total Bytes ReceivedThe value returned for the Total Bytes Received field is a cumulativecount of all data bytes received from t

10.17 Exceptions and Error ConditionsThe following exceptions and error conditions can occur with theMODE SELECT command.Illegal Value in MODE SELECT

10.18 Tape Format ExamplesThissectionprovidesexamplesforusingtheCTStowrite,appendto,and read tapes in the following formats:8500c format (EXB-8505)850

Writing and Reading in 8500c Format (EXB-8505)This section describes how to use the EXB-8505 to write, append to,and read tapes in 8500c format.Writin

Appending to 8500c Format TapesIf a tape has already been written in 8500c format and you want towrite additional data on the tape, follow these steps

Notes:xxii EXB-8205 and EXB-8505(Standard and XL)510503

Writing and Reading in 8500 Format (EXB-8505)This section describes how to use the EXB-8505 to write, append to,and read tapes in 8500 format.Writing

Reading 8500 Format TapesTo use the EXB-8505 to read an 8500 format tape, follow these steps:1. Load the data cartridge in the EXB-8505.2. Issue a REA

3. Issue a WRITE or WRITE FILEMARKS command to write theadditional data. The CTS automatically sets the Density Code to8200c format.Note: The WTF bit

Appending to 8200 Format TapesIf a tape has already been written in 8200 format and you want towrite additional data on the tape, follow these steps:1

If You Cannot Issue MODE SELECT CommandsIf you cannot issue MODE SELECT commands to set the DensityCode, follow these steps to write tapes in differen

11PREVENT/ALLOWMEDIUM REMOVAL(1Eh)BitByte76543210000001111001 Logical Unit Number Reserved02Reserved0304 Prevent05 Vendor Unique Reserved 0 0May 1994

11.1 About This CommandYou can use the PREVENT/ALLOW MEDIUM REMOVALcommand to allow or disallow the removal of the data cartridge fromthe CTS.Note: Th

11.2 Field DefinitionsByte 04, Bit 0 - PreventThe Prevent bit is used to prevent the removal of the data cartridgefrom the CTS, as follows:0–Allowthed

Notes:11-4EXB-8205 and EXB-8505(Standard and XL)51050311 PREVENT/ALLOW MEDIUM REMOVAL (1Eh)

12READ (08h)BitByte76543210000000100001 Logical Unit Number Reserved SILI Fixed02 (MSB)Transfer Length0304 (LSB)05 Vendor Unique Reserved 0 0May 1994

1CTS FeaturesThis chapter is an overview of the features of the EXABYTE®EXB-8505 and EXB-8205 8mm Cartridge Tape Subsystems (CTSs). Itprovides a compa

12.1 About This CommandThe READ command transfers one or more bytes or blocks of datafrom the CTS to the initiator, beginning with the next logical bl

Byte 01, Bit 0 - FixedThe Fixed bit defines the type of read operation being performed, asfollows:0 – A single logical block is read, and the length o

12.3 Exceptions and Error ConditionsThe following exceptions and error conditions can occur with theREAD command.Filemark DetectedIf the CTS detects a

Setmark Detected (EXB-8505 Only)Note: This error applies to tapes written in 8500c format only.If the RSmk bit in the MODE SELECT Device Configuration

EOD DetectedIf the CTS detects the EOD mark (or blank tape for 8200 format)during the read operation, it returns Check Condition status. TheREQUEST SE

PEOT or PEOP EncounteredDuring a read operation, if the CTS encounters the physical end oftape (PEOT) or the physical end of partition (PEOP) for 8500

Unrecoverable ErrorIf an unrecoverable media or hardware error occurs during the readoperation, the CTS terminates the READ command and returns CheckC

Transfer Length IncorrectIf the actual transfer length does not match the requested transferlength, the information reported depends on the setting of

Fixed Length Mode (Fixed = 1)If the Fixed bit is 1 and the actual length of any one block does notmatch the requested block length, the CTS transfers

Compression ErrorsThe CTS can report two types of compression errors during a readoperation:If the compression circuit is unable to decompress previou

Shown in Figure 1-1, the EXB-8505 and EXB-8205 are enhanced 8mmdigital helical-scan cartridge tape subsystems (CTSs) packaged in theindustry-standard

Notes:12-12EXB-8205 and EXB-8505(Standard and XL)51050312 READ (08h)

13READ BLOCK LIMITS(05h)BitByte76543210000000010101 Logical Unit Number Reserved02Reserved030405 Vendor Unique Reserved 0 0May 1994 EXB-8205 and EXB-8

13.1 About This CommandThe READ BLOCK LIMITS command requests that the CTS returndata identifying the maximum and minimum logical block lengthssupport

14READ BUFFER (3Ch)BitByte76543210000011110001 Logical Unit Number Reserved Mode02 Buffer ID03 (MSB)Buffer Offset0405 (LSB)06 (MSB)Allocation Length07

14.1 About This CommandThe READ BUFFER command is used to copy the CTS’s microcodeacross the SCSI bus to the initiator. This command is used with theW

14.3 Exceptions and Error ConditionsThe following exceptions and error conditions can occur with theREAD BUFFER command.Hardware or SCSI Bus ErrorIf a

Notes:14-4EXB-8205 and EXB-8505(Standard and XL)51050314 READ BUFFER (3Ch)

15READ POSITION (34h)BitByte76543210000011010001 Logical Unit Number Reserved BT02Reserved…0809 Vendor Unique Reserved 0 0May 1994 EXB-8205 and EXB-85

15.1 About This CommandThe READ POSITION command reports the CTS’s current logicalposition but does not cause tape motion to occur. As described inCha

15.3 Read Position DataWhen it completes the READ POSITION command, the CTS returns20 bytes of Read Position data to the initiator, as follows:BitByte

You can distinguish an XL CTS from a non-XL CTS by checking theunload button. The XL CTSs have a raised diamond pattern on theunload button. The non-X

Byte 00, Bit 6 - EOP (End of Partition)The EOP bit indicates whether the tape is positioned at the end of apartition, as follows:0 – The tape is not p

Bytes 04 through 07 - First Block LocationThe First Block Location field indicates the block address associatedwith the current logical block position

Notes:15-6EXB-8205 and EXB-8505(Standard and XL)51050315 READ POSITION (34h)

16RECEIVE DIAGNOSTICRESULTS (1Ch)BitByte76543210000001110001 Logical Unit Number Reserved02 Reserved03 (MSB)Allocation Length04 (LSB)05 TD VU Reserved

16.1 About This CommandYou can use the RECEIVE DIAGNOSTIC RESULTS command for anyof the following purposes:Obtaining the results of the tests requeste

16.2 Field DefinitionsBytes 03 and 04 - Allocation LengthThe Allocation Length field specifies the number of bytes that theinitiator has allocated for

16.3 Returning SEND DIAGNOSTIC DataWhen the initiator issues a RECEIVE DIAGNOSTIC RESULTScommand with the TD bit set to 0, the CTS returns a diagnosti

Bytes02and03-PageLengthThe Page Length field indicates the number Diagnostic Parameterbytes that follow this field. Table 16-2 indicates the Page Leng

16.4 Receiving a Processor Memory DumpThis section describes the steps and bit settings for receiving completeand partial processor memory dumps. Tabl

16.5 Receiving a Trace DumpThis section describes the steps and bit settings for receiving a tracedump. Trace dumps are used for detailed fault analys

1.1 Comparison of the Data FormatsSupported by the CTSsThe EXB-8505 reads and writes data in four logical formats:82008200c (compressed)85008500c (com

Format of SCSI Instruction Trace TableAs shown in Figure 16-1, the first 256 bytes of the trace dump includeinformation about SCSI commands that have

17RELEASE UNIT (17h)BitByte76543210000001011101 Logical Unit Number 3rdPty Third Party Dev ID RSVD02Reserved030405 Vendor Unique Reserved 0 0May 1994

17.1 About This CommandThe RELEASE UNIT command releases a CTS from an initiator’sexclusive use or, if third-party reservations are in effect, from an

18REQUEST SENSE (03h)BitByte76543210000000001101 Logical Unit Number Reserved02Reserved0304 Allocation Length05 CLRCNT VU Reserved 0 0May 1994 EXB-820

18.1 About This CommandThe REQUEST SENSE command requests that the CTS transfer sensedata to the initiator. The CTS returns a total of 29 (1Dh) bytes

18.3 Extended Sense BytesThe CTS supports the standard extended sense bytes, as follows:BitByte7654321000 Valid Error Code01 Segment Number02 FMK EOM

Byte 00, Bit 7 - ValidThis bit is set to 1 when the data in the Information bytes (bytes 03through 06) is valid for the command receiving the Check Co

Sense Key Meaning Explanation0h No SenseIndicates that there is no specific sense key information to bereported for the designated logical unit. This

Sense Key Meaning Explanation8h Blank CheckIndicates that EOD (blank tape) was encountered during aread, space, or locate operation.9h ExabyteThis is

Byte 09 - Log Parameter CodeWhen a log parameter (write or read error counter) meets thethreshold criteria specified with the TMC bit in the LOG SELEC

8200 format(EXB-8205and EXB-8505)8200c format*(EXB-8205and EXB-8505)8500 format(EXB-8505)8500c format*(EXB-8505)Maximum sustaineddata transfer rate262

Byte 13 - Additional Sense Code Qualifier (ASCQ)The Additional Sense Code Qualifier, in conjunction with theAdditional Sense Code (byte 12), provides

Bytes 19 through 21 - Unit SenseFor each status bit defined in the Unit Sense bytes, the normal orGood status is 0. When set to 1, these bytes indicat

Byte 20, Bits 5 - WP (Write Protect) The data cartridge is writeprotected.Byte 20, Bit 4 - FMKE (Filemark Error) A write error occurred whenthe CTS wa

Byte 22 - ReservedThis byte is reserved.Bytes 23 through 25 - Remaining TapeThe Remaining Tape field indicates the amount of tape remaining in1,024-by

Byte 28 - Fault Symptom CodeThe Fault Symptom Code (FSC) field is an Exabyte-unique byte usedto indicate the specific nature of hardware and software

19RESERVE UNIT (16h)BitByte76543210000001011001 Logical Unit No 3rdPty Third Party Dev ID RSVD02Reserved030405 Vendor Unique Reserved 0 0May 1994 EXB-

19.1 About This CommandThe RESERVE UNIT command reserves the CTS for an initiator’sexclusive use or, if third-party reservations are in effect, for an

20REWIND (01h)BitByte76543210000000000101 Logical Unit Number Reserved Immed02Reserved030405 Vendor Unique Reserved 0 0May 1994 EXB-8205 and EXB-8505(

20.1 About This CommandTheREWINDcommandcausestheCTStorewindthetapetothelogical beginning of tape (LBOT) or, if the tape is formatted with twopartition

20.2 Field DefinitionsByte 01, Bit 0 - ImmedThe Immed bit is used to determine when command status isreturned to the initiator, as follows:0 – Status

1.2 Structure of Data on TapeThis section provides more in-depth information about the dataformats supported by the CTSs. It discusses:The physical st

Notes:20-4EXB-8205 and EXB-8505(Standard and XL)51050320 REWIND (01h)

21SEND DIAGNOSTIC(1Dh)BitByte76543210000001110101 Logical Unit Number PF RSVD SelfTest DevOfL UntOfL02 Reserved03 (MSB)Parameter List Length04 (LSB)05

21.1 About This CommandThe SEND DIAGNOSTIC command causes the CTS to performcertain self-diagnostic tests. If a test is successful, the CTS returnsGoo

21.2 Field DefinitionsByte 01, Bit 4 - PF (Page Format)The Page Format bit specifies the format of the parameter list for theSEND DIAGNOSTIC command.

21.3 Diagnostic TestsTable 21-1 lists the valid combinations of the SelfTest, DevOfL,UntOfL, Parameter List Length, and MD fields in the SENDDIAGNOSTI

21.4 Test DescriptionsThis section describes the memory dump and each type of diagnostictest.Processor Memory DumpThe memory dump returns the current

Test 100 (Power-on Tests without Tape)During this test, the CTS performs its power-on RAM and servodiagnostic tests. The CTS returns Good status if it

Note: Test 101 erases the trace tables. In addition, the unload buttonis disabled during this test.Setup for Test 101Before starting this test, power

Test 111 (Power-on, Write/Read, and LoadTests withTape—Tape Preloaded at Start of Test)During this test, the CTS first performs its power-on RAM and s

22SPACE (11h)BitByte76543210000001000101 Logical Unit Number Reserved Code02 (MSB)Count0304 (LSB)05 ADE VU Reserved 0 0May 1994 EXB-8205 and EXB-8505(

Single-Azimuth Compressed (8200c Physical Format)Both the EXB-8505 and EXB-8205 write and read this format. In thisformat:One write head writes a sing

22.1 About This CommandThe SPACE command enables the CTS to perform forward orbackward searches. You can use this command to space directly to theend

22.2 Field DefinitionsByte 01, Bits 2 through 0 - CodeAs shown in Table 22-1, the Code field specifies the type of spaceoperation you want the CTS to

Bytes 02 through 04 - CountThe Count field represents the number of blocks, filemarks, orsetmarks (8500c format only) to be spaced over. The value of

Byte05,Bit6-VendorUniqueThere is no vendor unique definition for this bit.22.3 Exceptions and Error ConditionsThe following exceptions and error condi

Setmark Detected (EXB-8505)Note: This error applies to tapes written in 8500c format only.If the Code field has a value of 000b (space over n logical

EOD (Blank Tape) DetectedIf the Code field has a value of 000b (space over n logical blocks), 001b(space over n filemarks), or 100b (space over n setm

PEOT or PEOP EncounteredIf the physical end of tape (PEOT) or physical end of partition (PEOP)for 8500c format is encountered during a space operation

PBOT or PBOP EncounteredIf the Code field has a value of 000b, 001b, or 100b (space over logicalblocks, filemarks, or setmarks) and the physical begin

Unrecoverable ErrorIf an unrecoverable media or hardware error occurs during the spaceoperation, the CTS terminates the SPACE command and returnsCheck

23TEST UNIT READY(00h)BitByte76543210000000000001 Logical Unit Number Reserved02Reserved030405 Vendor Unique Reserved 0 0May 1994 EXB-8205 and EXB-850

Product Warranty CautionThe EXB-8505, EXB-8505XL, EXB-8205, and EXB-8205XL 8mmCartridge Tape Subsystems (CTSs) are warranted to be free fromdefects in

Figure 1-2 Relationship of 8mm physical track structures to logical data formats1-8EXB-8205 and EXB-8505(Standard and XL)5105031 CTS Features

23.1 About This CommandThe TEST UNIT READY command provides a means for determiningif the CTS is ready to accept an appropriate medium access command.

24VERIFY (13h)BitByte76543210000001001101 Logical Unit Number Reserved Immed BytCmp Fixed02 (MSB)Verification Length0304 (LSB)05 Vendor Unique Reserve

24.1 About This CommandThe VERIFY command enables the CTS to verify one or more logicalblocks of data on the tape, beginning with the next logical blo

Note: The CTS returns Check Condition status with the sense keyset to Illegal Request (5h) if the Fixed field in the VERIFYcommand is 1 (fixed-length

24.3 Exceptions and Error ConditionsThe following exceptions and error conditions can occur with theVERIFY command.Filemark DetectedIf a filemark is d

Setmark Detected (EXB-8505 Only)Note: This error applies to tapes written in 8500c format only.If the RSmk bit in the MODE SELECT Device Configuration

EOD DetectedIf the CTS detects the EOD mark (or blank tape in 8200 format) duringthe verify operation, it returns Check Condition status. The REQUESTS

Unrecoverable ErrorIf an unrecoverable media or hardware error occurs during the verifyoperation, the CTS terminates the VERIFY command and returnsChe

Verification Length IncorrectIftheactualverificationlengthdoesnotmatchtherequestedverification length, the information reported depends on the setting

Fixed Length Mode (Fixed = 1)If the Fixed bit is 1 and the actual length of any one block does notmatch the requested block length, the CTS verifies t

Data Elements on TapeFigure 1-3 summarizes the structure of data written to tape and showsthe elements that make up data tracks and blocks. This illus

Notes:24-10EXB-8205 and EXB-8505(Standard and XL)51050324 VERIFY (13h)

25WRITE (0Ah)BitByte76543210000000101001 Logical Unit Number Reserved Fixed02 (MSB)Transfer Length0304 (LSB)05 Vendor Unique Reserved 0 0May 1994 EXB-

25.1 About This CommandThe WRITE command transfers one or more bytes or blocks of datafrom the initiator to the CTS. As described in Section 1.1, theE

Bytes 02 through 04 - Transfer LengthThe Transfer Length field defines the amount of data you want theCTS to write, as follows:When the Fixed bit is s

25.3 Tape PositioningThis section describes the legal tape positions for a write operation.Tape Positioned at LBOT or LBOPWhen writing to a tape posit

25.4 Data BufferingThe CTS provides two modes of operation for the WRITE command:unbuffered and buffered. The mode of operation is set with theMODE SE

25.5 Exceptions and Error ConditionsThe following exceptions and error conditions can occur with theWRITE command.Write-Protected Data CartridgeIf a w

Setting of Fixed bit in current CDBFixed=0(variable-length logical block)Fixed=1(fixed-length logical blocks)LEOT or LEOPencounteredduring currentwrit

Encountering LEOT or LEOP Because of a Previous WRITECommandTo understand how LEOT or LEOP (8500c format only) can beencountered because of a previous

Example1. The initiator issues five buffered WRITE commands to the CTS(WRITE 1 through WRITE 5). The 500 KBytes of data (assumedto be uncompressed) as

Physical Beginning of Tape (PBOT)PBOT is located at the point on the tape where the translucent leadermaterial is attached to the media. This position

5. As the CTS writes the data associated with WRITE 2 to tape, itencounters LEOT. As a result, the next WRITE command(WRITE 9) terminates abnormally a

PEOT or PEOP EncounteredIf the physical end of tape (PEOT) or physical end of partition (PEOP)for 8500c format is encountered, the CTS terminates the

Compression ErrorsIf you are writing in compressed format and the decompressed datadoes not match the compressed data during the CompressionIntegrity

Illegal RequestsThe following conditions cause the CTS to return Check Conditionstatus with the sense key set to Illegal Request (5h):The Fixed bit is

Notes:25-14EXB-8205 and EXB-8505(Standard and XL)51050325 WRITE (0Ah)

26WRITE BUFFER (3Bh)BitByte76543210000011101101 Logical Unit Number Reserved Mode02 Buffer ID03 (MSB)Buffer Offset0405 (LSB)06 (MSB)Parameter List Len

26.1 About This CommandThe WRITE BUFFER command allows you to load new microcodefrom the SCSI bus into the CTS’s control memories. This command isused

Cautions for Using the WRITE BUFFER CommandCAUTIONBe sure to follow these cautions when issuing the WRITEBUFFER command:The WRITE BUFFER command allow

26.2 Field DefinitionsByte 01, Bits 2 through 0 - ModeTheModefielddeterminesthetypeofoperationtobeperformed.Theonly operation supported by the CTS is

Byte 09, Bit 7 - WBF (WRITE BUFFERs Follow)The WBF bit specifies whether the new microcode is being sent usingone or more WRITE BUFFER commands, as fo

The CTS writes an EOD mark when you press the unload button orissue one of the following commands immediately after the CTScompletes a WRITE or WRITE

Fatal Load ErrorOnce the load process is started, it is irreversible. If a hardware orpower failure occurs during the load operation, the CTS may not

27WRITE FILEMARKS(10h)BitByte76543210000001000001 Logical Unit Number Reserved WSmk Immed02 (MSB)Number of Filemarks0304 (LSB)05 Short VU Reserved 0 0

27.1 About This CommandThe WRITE FILEMARKS command causes the CTS to write one ormore filemarks or setmarks (available in 8500c format only) to tape.I

Byte 01, Bit 0 - ImmedThe Immediate bit determines when command status is returned tothe initiator, as follows:0 – Status is reported to the initiator

27.3 Tape PositioningThis section describes the legal tape positions for a write filemarksoperation.Tape Positioned at LBOT or LBOPWhen writing to a t

27.4 Exceptions and Error ConditionsThe following exceptions and error conditions can occur with theWRITE FILEMARKS command.Write-Protected Data Cartr

PEOT or PEOP EncounteredIf the physical end of tape (PEOT) or physical end of partition (PEOP)for 8500c format is encountered, the CTS terminates the

AEEPROM OptionsThis appendix describes the CTS’s EEPROM options and describeshow you can request these options when you order a CTS fromExabyte. As th

What are EEPROM Options?When the CTS is manufactured, many of its operating features anddefault values are programmed in electronically erasableprogra

How to Use This AppendixThe tables in this appendix are grouped by EEPROM option function,as described below. A sample table on the next page shows th

Physical Blocks Each physical track contains eight physicalblocks. A physical block containing user data includes thefollowing:14 bytes of header info

Hardware Operation OptionsThese are options that permanently determine how various CTShardware features operate. You cannot change these options witha

EEPROM Options for MODE SELECT DefaultsAs shown in Table A-1, many EEPROM options allow you to specifythe power-on defaults for various fields in the

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...Read retrycountRead Retry Count –Byte03ofthe Read-Write Error RecoveryPage—see pa

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...Write delaytimeWrite Delay Time – Bytes 06and 07 of the DeviceConfiguration Page—

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...Nodisconnectduring datatransferND – Byte 02, bit 5, of theVendor Unique Parameter

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...GapthresholdGap Threshold –Byte05oftheVendor Unique ParametersPage 1—see page 10-

EEPROM Options for INQUIRY DataAs shown in Table A-3, several EEPROM options are available forcontrolling the data returned by the CTS in response to

EEPROM Options for MODE SELECT / MODE SENSEAs shown in Table A-4, several EEPROM options are available forcontrolling how the MODE SELECT (15h) and MO

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...IgnoreillegaldensitychangesControls the reporting oferrors if you attempt tochang

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...ReportMedia Typein MODESENSEControls what is reportedfor the Medium Type bytein M

Search FieldsEach track of data contains search fields used for high-speed search.High-speed search occurs when the initiator issues a LOCATE(2Bh) or

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...REQUESTSENSEformatSpecifies the number ofbytes of data returned bythe REQUEST SEN

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...Set EOM atLEOTControls what the CTSreports when it encountersLEOT during a readop

EEPROMoptionDefinition Possible values DefaultvalueOptionis setto...LOCATEcommandControls whether the CTSsupports the LOCATE(2Bh) command.See Chapter

EEPROMoptionDefinition Possible values DefaultvalueOptionis setto...RECEIVEDIAGNOSTICRESULTScommandControls how theRECEIVE DIAGNOSTICRESULTS (1Ch)comm

EEPROMoptionDefinition Possible values DefaultvalueOptionis setto...SENDDIAGNOSTICspecialoperationControls the reporting ofan error if a tape is prese

EEPROMoptionDefinition Possible values DefaultvalueOptionis setto...SPACEcommandControls how thespace-to-EOD operation ofthe SPACE (11h)command operat

EEPROMoptionDefinition Possible values DefaultvalueOptionis setto...ImmediateWriteFilemarkControls whether the CTSsupports the Immed bit(byte 01, bit

EEPROM Options for Hardware OperationsAs shown in Table A-7, a number of EEPROM options allow you tocustomize CTS hardware operations. You cannot over

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...Autosizethe tapeControls how the CTS autosizestapes.See Appendix C for moreinform

EEPROM Options for the SCSI ConfigurationAs shown in Table A-8, a number of EEPROM options allow you tocustomize the CTS’s SCSI configuration. You can

Unload ButtonThe unload button is the only operator control on the CTS. It isused to unload the tape from the CTS. Depending on the CTS’sEEPROM image

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...MaximumreselectiontriesControls the maximum numberof times that the CTS willattem

EEPROMoptionDefinition Possible values DefaultvalueOption isset to...Status/CommandCompleteControls whether the CTS dropsthe BSY line quickly (about5

True Areal Density Selection EEPROM OptionThe True Areal Density Selection option enables you to choose howthe Density Code and the Data Compression P

EXB-8205 For the EXB-8205, the following Density Codes are available:00h Default format14h 8200 uncompressed format7Fh Nochangeinformat90h 8200c compr

Table A-9 lists the data formats resulting when you specify variouscombinations of Density Code and the DCE bit in MODE SELECTwith the SCSI-2 option.D

If the tapeformat is...EXB-8500 Option SCSI-2 OptionDensity Codereturned as..DCEreturned as...Density Codereturned as..DCEreturned as..8200 14h 0 14h

The following sections describe these options in more detail.WRITE Option (MODE SELECT sets the writing format)The WRITE option reflects the Density C

MODESELECTissued when...Density Code andDCE bit set to...Is itlegal?Does it change thedefault writingformat?Does it change thecurrent writingformat?Ta

Effect of the READ Option on DCE Bit in MODE SENSE DataThe value returned for the DCE bit in MODE SENSE for the READoption depends on the type of MODE

In contrast, suppose you attempt to change the Density Code to14h after completing step 3. The EXB-8505 returns CheckCondition status with the sense k

LEDsThe CTS uses three LEDs (see Figure 1-5) to indicate its variousoperating states. The LEDs indicate the following generalconditions:When the top (

BDirectory SupportThe CTS’s directory support feature provides a method ofmaintaining a directory on a tape when partition support is notavailable. Yo

Overview of Directory SupportThe sample application in this appendix shows one method forcreating a tape that uses the directory support feature. This

Sample Application for Directory SupportThe step-by-step description that follows explains how to create thisdata structure and access the data using

Converting EXB-8200SX DriversEXB-8200SX directory support drivers should work for EXB-8505 orEXB-8205 directory support with only a few modifications.

Writing Data for Directory SupportTo write data to make use of the directory support feature and theREAD POSITION and LOCATE commands, follow these st

2. Using additional uncompressed “filler” data, create a secondpad after the directory pad. The minimum size for the secondpad is 12 MBytes. This pad

5. Writethefirstdataset(DS1)tothetape.Whilethedatasetisbeing written, issue additional READ POSITION commands asdesired to obtain the locations of ind

B-8EXB-8205 and EXB-8505(Standard and XL)510503Appendix B Directory Support

7. Write the READ POSITION data obtained for the various filesand blocks in the first data set (DS 1) to the first data set’sdirectory (DIR 1).8. Repe

11. Rewind the tape to LBOT. This creates an EOD mark at the endof the master directory (EOD 1) that overwrites most of the12-MByte pad.Note: After wr

Table 1-4 shows specific combinations of LEDs that may occur duringoperation.CTS StatePOST(1stpart)POST(to com-pletion)FailedPOSTReady–no tapeloadedRe

Accessing Data on a Directory Support TapeTo use the LOCATE command to access the data written in theprevious section, follow these steps:1. Read the

3. Once you have found a directory that lists the file you need,issue another LOCATE command to reach that file, using theREAD POSITION data from the

Notes:May 1994 EXB-8205 and EXB-8505(Standard and XL)B-13Appendix B Directory Support

CData CartridgeCapacitiesThis appendix lists capacities and track and physical block counts forthe different sizes of EXATAPE™ data cartridges. It als

EXATAPE CapacitiesExabyte strongly recommends that you use EXATAPE data-grademetal-particle media with your EXB-8205 or EXB-8505. Do notattempt to us

Track and Physical Block CountsTables C-2 and C-3 list the following information for EXATAPE datacartridges written in 8500c, 8500, 8200c, and 8200 fo

Autosizing of Data CartridgesAutosizing is the process that occurs during a load operation whenthe CTS spaces forward from the physical beginning of t

DSCSI Bus MessageProcessing and ErrorRecoveryThis appendix describes message processing and error handling bythe CTS and the appropriate initiator res

SCSI Bus Error Recovery (Initiators Supportingthe Command Complete Message Only)This section describes the actions to be taken by the initiator and th

Message Processing / SCSI Bus Error Recovery(Initiators Supporting Other Messages)This section describes CTS message processing and SCSI bus errorreco

1.4 Customizing CTS Operation with EEPROMOptionsWhen the EXB-8505 and EXB-8205 are manufactured, a number ofdefault values are programmed into the CTS

Message Processing after the Selection PhaseFigure D-1 shows that the CTS will only accept three legal messagesimmediately after the Selection phase (

Initial Phase:SelectionTransition to: Message OutAbort All othersGoBusFreeGotoCDBInphaseIsAttentionhigh?IsLUNvalid(equal0)?IsDisconnectbitset?Identify

Message Processing in the Message Out PhaseFigure D-2 shows the message sequences for Message Out bytesreceived during a previously initiated Message

Initial Phase:Message OutTransition to: Message OutGoBusFreeGoBusFreeYesNoAbortprocessGoBusFreeDoesinitiatorowncurrentprocess?IsDisconnectbitset?Conti

Processing during the Command Out PhaseFigure D-3 shows how CDB bytes are processed. Note that the GroupCode in the CDB’s first byte determines how ma

Message Processing in the Message Out Phase afterCommand PhaseFigure D-4 shows how messages are processed after the Commandphase and before any Data p

Initial Phase:Message OutTransition to: Message OutGoBusFreeGoBusFreeYesNoAbortprocessGoBusFreeDoesinitiatorowncurrentprocess?IsDisconnectbitset?Conti

Processing of Extended Message OutFigure D-5 shows how Extended Message Out messages areprocessed. Note that the Attention signal must coincide with t

ExtendedMessage Processing(message bytesout)Receivemessagebyte00Receivemessagebyte01Receivemessagebyte02Receivemessagebyte03Receivemessagebyte04Isit01

Processing of Extended Message InFigure D-6 shows how the Extended Message In messages areprocessed. The CTS executes this message sequence in respons

Changes and Enhancements to This ManualThis revision (510503-004) of the EXB-8205 and EXB-8505 SCSIReference for Standard and eXtended-Length (XL) Con

Notes:1-18EXB-8205 and EXB-8505(Standard and XL)5105031 CTS Features

ExtendedMessage Processing(message bytesin)Send messagebyte00;value=01hSend messagebyte01;value=03hSend messagebyte02;value=01hSend messagebyte03;valu

Message Processing in Data Out Phase (WRITECommand)Figure D-7 shows how each message is processed during the DataOut phase of a WRITE command.Parity E

Initial Phase:DataOutTransition to: Message Out(write datatotape)IsDisconnectbitset?ContinueprocessingDisallowdisconnectsAllowdisconnectsIdentifyNoYes

Message Processing in Data Out Phase (InformationCommands)Figure D-8 shows how messages are processed during the Data Outphase for commands other than

Initial Phase:DataOut (InformationComma n d)Transition to: Message Out(for example, MODESELECT)YesAbortprocessGoBusFreeDoesinitiatorowncurrentprocess?

Message Processing in Data In Phase (READ Command)Figure D-9 shows how messages are processed during the Data Inphase of a READ command (that is, when

Initial Phase:Data InTransition to: Message Out(Readdatafromtape)IsDisconnectbitset?Continue processingDisallowdisconnectsAllowdisconnectsIdentifyNoYe

Message Processing in Data In Phase (InformationCommands)Figure D-10 shows how messages are processed during the Data Inphase for commands other than

Initial Phase:Data In (InformationCommand)Transition to: Message Out(for example, INQUIRY, REQUESTSENSE)SetsensekeytoAbortedCommand(Bh)GotoStatusphase

Message Processing In Status In PhaseFigure D-11 shows how messages are processed during the Status Inphase. Note that attempts to change the physical

2SCSI CommunicationThis chapter provides an overview of how the Small ComputerSystem Interface (SCSI) is implemented for the EXB-8505 andEXB-8205. It

Message Processing in Message In Phase (CommandComplete)Figure D-12 shows how messages are processed while the CTS isattempting to send the Command Co

Message Processing after ReselectionFigure D-13 shows how messages are processed after the CTS hasreselected the initiator and sent the Identify messa

ExtendedMessageContinueprocessingNo OperationGoBusFreeGoBusFreeResetExecute warmresetMessage ParityErrorContinueprocessingSetsensekeytoAbortedCommand(

Message Processing during Disconnect SequenceFigure D-14 shows how messages are processed while the CTS isexecuting the “disconnect” sequence. Note th

YesNoAbortprocessDoesinitiatorowncurrentprocess?YesAbortGoBusFreeGoBusFreeResetExecutewarmresetContinueprocessingNo OperationGoBusFreeExtendedMessageM

EError InformationThis appendix is a reference for:The Additional Sense Codes (ASCs) and Additional Sense CodeQualifiers (ASCQs) returned by the REQUE

REQUEST SENSE InformationThis section lists the possible combinations of values for theAdditional Sense Code (ASC) and the Additional Sense CodeQualif

Sense Key = 1h (Recovered Error)ASC(Byte 12)ASCQ(Byte 13)Explanation Related FSC5Bh 02hLog parameter overflow (a cumulative counterreached its maximum

Sense Key = 3h (Medium Error)ASC(Byte 12)ASCQ(Byte 13)Explanation Related FSC00h 02hPEOT or PEOP was encountered during aspace or locate operation.34h

Sense Key = 4h (Hardware Error)ASC(Byte 12)ASCQ(Byte 13)Explanation Related FSC00h 00hUndetermined hardware error.58h, 5Ah, 67h, 68h, 6Dh,FAh, FCh, FD

2.1 Overview of SCSI CommunicationTable 2-1 shows the commands, status information, and messages thatare supported by the CTS during SCSI bus phases.S

ASC(Byte 12)ASCQ(Byte 13)Explanation Related FSC3Dh 00h Illegal bit set in Identify message. DAh4Eh 00hOverlapped commands attempted—Badinitiator-targ

Sense Key = 7h (Data Protect)ASC(Byte 12)ASCQ(Byte 13)Explanation Related FSC27h 00hThe tape is write protected.03h, 27h, 4ChSense Key = 8h (Blank Che

Sense Key = Bh (Aborted Command)ASC(Byte 12)ASCQ(Byte 13)Explanation Related FSC00h 00hNo additional sense information. Refer to theFault Symptom code

Fault Symptom CodesThis section lists the Fault Symptom Codes that may be returned bythe REQUEST SENSE (03h) command. The Fault Symptom Code isreturne

Fault Symptom Code DescriptionsFSC SK ERP Description02h 5h 11A WRITE command was received when the tape was not at alegal position to write.03h 7h 5A

FSC SK ERP Description1Dh 0h 11A setmark was encountered during a read or verify operation.26h 5h 11A WRITE FILEMARKS command was received when the ta

FSC SK ERP Description64h 3h 11Bank 1 of control load image was not valid when loadingfirmware.65h 3h 11 The EEPROM load image was not valid when load

FSC SK ERP DescriptionA1h 4h 8, 12Hardware failure—Head sync error during write.A2h 4h 8, 12 Underrun error during write.A3h Bh 13 IPORT write buffer

FSC SK ERP DescriptionCAh 6h 3Unit Attention–Log threshold met. (For more information aboutthis error, look at the Log Parameter Page Code and LogPara

FSC SK ERP DescriptionE7h Bh 11The initiator sent an Abort or Initiator Detected Error messageduring a read operation and the command was aborted.EAh

SCSI Bus Phase ExplanationData In/OutThe CTS drives the bus to one of the Data phases and sends orreceives data.StatusThe CTS returns one byte of stat

Error Recovery ProceduresTable E-14 describes the error recovery procedures (ERPs)recommended for each Fault Symptom Code listed in Table E-13.Note: I

Glossary8200 formatA non-compressed data format written and read byall Exabyte 8mm CTSs.8200c formatA compressed data format written and read by theEX

ASCQAdditionalSenseCodeQualifier.Thisbyteisreturned as byte 13 of the REQUEST SENSEextended sense data. The ASCQ, in conjunctionwith the Additional Se

early warningThe logical end of tape (LEOT) or logical end ofpartition (LEOP).ECCError correction code.ECMAEuropean Computer Manufacturers Association

EXB-8500cThe EXB-8500c 8mm Cartridge Tape Subsystem.The EXB-8500c is physically similar to theEXB-8500, but offers data compression as anoption. Assum

ISOInternational Standards Organization.KByteKilobyte.LBOPLogical beginning of partition.LBOTLogical beginning of tape.LEOPLogical end of partition.LE

PBOPPhysical beginning of partition.PBOTPhysical beginning of tape.PEOPPhysical end of partition.PEOTPhysical end of tape.POSTPower-on self-test, whic

signal releaseWhen a signal is not driven by a bus but is biasedby the cable terminators to the false state.statusInformation sent from the target to

Notes:G-8EXB-8205 and EXB-8505(Standard and XL)510503Glossary

Index!8200 formatappending to 10-67filemarks 3-15 to 3-16logical block structure 1-11physical block structure 1-11reading 10-67writing 10-668200c form

2.2 SCSI Commands Supported by the CTSsThe EXB-8505 and EXB-8205 support the SCSI commands shown inTable 2-2.CommandOperationcode(hex)What the CTS doe

CCDB 2-9 to 2-11Check Condition status 2-13cleaning the CTSCLN bit 18-10CLND bit 18-10LED indicators for 1-16REQUEST SENSE indicators for 18-10UCLN bi

EEBD bit 10-22, 10-53EEPROM optionsAllow position past EOD B-1Button action 1-14, 3-3Command queuing 3-36, 6-3Default write format 3-10 to 3-11defined

IIdentify message 2-21Illegal Request (5h) sense keyASC and ASCQ values for E-5 to E-6described 18-5LOCATE 7-9READ 12-10SPACE 22-10VERIFY 24-9WRITE 25

MODE SELECT command (cont.)parameter list length 10-4 to 10-7Read-Write Error Recovery Page 10-25 to 10-27RLEC bit 10-31RSmk bit 10-41Vendor Unique Pa

PEOTdefined 1-11detected during locate 7-8detected during read 12-7detected during space 22-8detected during verify 24-6detected during write 25-11det

SSave Data Pointer (02h) message 2-18SCSIbus phases 2-2 to 2-3bus reset 3-35command descriptor block 2-9 to 2-11command format 2-7 to 2-8command forma

Vvariable-length logical blocks 10-20Vendor Unique Parameters Page 1 10-51 to 10-55Vendor Unique Parameters Page 2 10-56 to 10-57vendor-unique paramet

CommandOperationcode(hex)What the CTS doesin response to this commandDescribedinMODESELECT15hChanges the CTS’s internal medium, logical unit, ordevice

CommandOperationcode(hex)What the CTS doesin response to this commandDescribedinSENDDIAGNOSTIC1DhPerforms diagnostic functions specified by theinitiat

2.3 SCSI Command FormatThe SCSI command formats for the six- and ten-byte commands areshownintheANSI Small Computer System Interface 2 (SCSI-2)standar

Format of the Operation CodeBitByte7654321000 Group Code Command CodeTypical Format of the Control ByteBitByte76543210nn Vendor Unique Reserved Flag L

2.4 Field Definitions for the CommandDescriptor BlockThe following sections provide field definitions for the six- andten-byte command descriptor bloc

ContentsAbout This Manual xix1 CTS Features 1-11.1 Comparison of the Data Formats Supported by the CTSs . . . . . . . . . . . . . 1-41.2StructureofDat

Byte 05 - Control ByteThe Vendor Unique portion of the Control byte is defined for eachspecific command, if used. The CTS does not support linkedcomma

Byte 06 - ReservedThis byte is reserved.Bytes 07 and 08 - Transfer, Parameter List, or AllocationLengthThese bytes contain the transfer length, the pa

Depending on the specific error, the Additional Sense Code (ASC)is set to Illegal Operation Code (20h), Logical Unit Not Supported(25h), or Invalid Fi

ThefollowingaredefinitionsofthestatusbytessupportedbytheCTS.Good StatusGood status indicates that the operation specified by the CDBcompleted normally

BusyBusy status indicates that the CTS is in the busy state. The CTS is in abusy state when it is performing an internal operation that will notallow

2.7 Message SystemThe message system allows communication between the initiator andthe CTS for physical path management. Table 2-4 lists the messagess

Command Complete (00h)The CTS sends the Command Complete message to the initiator toindicate that the execution of a command has terminated and thatva

The format of the Synchronous Data Transfer Request message is asfollows:BitByte76543210000000000101 Extended Message Length02 Extended Message Code03

Save Data Pointer (02h)The CTS sends the Save Data Pointer message to direct the initiator tosave a copy of its present active data pointer for the CT

Initiator Detected Error (05h)The initiator sends the Initiator Detected Error message to inform theCTS that an error has occurred that does not precl

3 Implementing CTS Operations 3-13.1UsingDataCartridges... 3-2LoadingDataCartridges...3-3Un

No Operation (08h)The initiator sends the No Operation message in response to theCTS’s request for a message when the initiator does not currentlyhave

Identify (80h or C0h)Either the initiator or the CTS can send the Identify message. Themessage is used to establish the physical path connection betwe

Message SequenceWhen the CTS connects to the SCSI bus, the following sequence ofevents occurs:1. The initiator indicates its ability to accommodate mo

3Implementing CTSOperationsThis chapter explains how to implement common CTS operations. Itincludes information about the following:Using data cartri

3.1 Using Data CartridgesTo ensure optimum data reliability and minimize wear on the CTS’srecording heads, Exabyte strongly recommends the use ofEXATA

EXATAPE 8mm Data Cartridge15m 54m 112m 160m XLEXB-8205 andEXB-8505✔✔✔Not supported(automaticallyejected)EXB-8205XL andEXB-8505XL✔✔✔✔EXB-8200 andEXB-82

Normal Unload ButtonIf the CTS’s EEPROM image includes the “normal” unload buttonsetting (default), the following actions occur when you press theunlo

3. The tape is rewound to the physical beginning of tape (PBOT).4. The tape is unloaded from the tape path.5. The data cartridge is ejected.CAUTIONWhe

5. The data cartridge is ejected.6. The CTS is reset. CAUTION• Since the tape is not rewound when you use the “superfast” version of the unload butto

Status Reported for Unload ProcedureIf a command is issued to the CTS during the unload procedure, theCTS returns Check Condition status with the sens

6 LOAD/UNLOAD (1Bh) 6-16.1AboutThisCommand... 6-26.2FieldDefinitions... 6-47LOCATE (2

3.2 Controlling the Format of Data on the TapeAs described in Chapter 1, the EXB-8505 reads and writes tapes infour logical formats: 8500c, 8500, 820

3.3 Using Data CompressionWhen writing in either 8200c or 8500c format, the CTS uses theImproved Data Recording Capability (IDRC) compression algorith

Using the EXB-8505 to Write Compressed DataThe EXB-8505 writes compressed data in two different formats: 8200cand 8500c. The default data format for

Using the EXB-8205 to Write Compressed DataThe EXB-8205 writes compressed data in 8200c format only. Thedefault data format for the EXB-8205 is typic

3.4 Setting the Size of Data BlocksYou may want to adjust the block size of the data being transferredfrom the host to the CTS to use the maximum capa

3. The third physical block written to tape contains 1,024 bytes ofdata from the host.4. The fourth physical block contains 512 bytes of host data and

ExampleIn an extreme case, suppose that the host is sending a series ofone-byte logical blocks to the CTS. Tape capacity is used as follows:1. The CT

3.5 Using Filemarks and SetmarksFilemarks and setmarks enable an initiator to locate particular blocksof data using high-speed search. When writing d

Note: The short filemark in 8200 format is equivalent to the alternateshort filemark written by the EXB-8200SX. Refer to theEXB-8200SX 8mm Cartridge

3.6 Using Streaming vs. Start/Stop ModeThe CTS includes a 1-MByte data buffer that enables it to operate aseither a streaming tape device or as a star

11 PREVENT/ALLOW MEDIUM REMOVAL (1Eh) 11-111.1AboutThisCommand ... 11-211.2FieldDefinitions...

Start/stop activity increases the amount of wear on the tape and theCTS’s recording heads. It also decreases the amount of data that canbe stored on

Using the Motion Threshold and Reconnect ThresholdThis section explains how to increase the efficiency of data transfers toand from the CTS’s buffer b

Motion ThresholdThe motion threshold is used in start/stop mode to control datatransfers between the buffer and the tape. The motion threshold ismeas

Reconnect ThresholdThe reconnect threshold is used in streaming mode to control datatransfers between the buffer and the initiator. The reconnectthre

Summary of Motion and Reconnect ThresholdsTable 3-6 provides summary information about the motion andreconnect thresholds.DefaultvalueWhat itcontrols.

3.7 Formatting and Using Partitions (EXB-8505)In 8500c format, the EXB-8505 can write and read tapes containingeither one or two partitions. Partitio

Each partition on a tape contains a logical and physical beginning(LBOP and PBOP) and a logical and physical end (LEOP and PEOP).The EXB-8505 consider

As shown in Figure 3-1, the first partition on a dual-partition tape isPartition 1, and the second partition is Partition 0. For adual-partition tape

1. Load a tape into the EXB-8505, or rewind the current tape to thelogical beginning of tape (LBOT). The tape must be positionedat LBOT or at the log

How Do You Use a Dual-Partition Tape?The easiest way to understand how to use a dual-partition tape is tothink of it as two separate tapes. Just as y

18 REQUEST SENSE (03h) 18-118.1AboutThisCommand...18-218.2FieldDefinitions ...18-218.3E

Changing PartitionsIf you want to move the tape from one partition to the logicalbeginning of the other partition (LBOP), use the LOCATE commandwith t

Writing Data in PartitionsTo write data, use the WRITE (0Ah) command as you would with astandard tape. However, remember that if you want to write da

Reading Data on a Partitioned TapeTo read data, use the READ (08h) command as you would with astandard tape. However, remember that if you want to re

ImportantWhen you reformat a dual-partition tape to create asingle-partition tape, all of the information defining theoriginal two partitions is erase

3.9 Handling Unit Attention ConditionsThe CTS creates a Unit Attention condition for each initiator whenany of the following conditions occurs:The CTS

When you insert a data cartridge into the CTS, the CTS returns CheckCondition status with the sense key set to Unit Attention (6h).However, if you ins

3.10 Resetting the CTSYou can use any of the following methods to reset the CTS:Power the CTS off and back on again (power-on reset).If a servo or har

Effect of SCSI Bus and Device ResetsSCSI bus and device resets have the following effects:If the CTS is connected to the SCSI bus, the SCSI bus goes t

Reset ProcessingThis section specifies how the CTS processes power-on resets, SCSIbus resets, and device resets. The CTS processes resets differentlyd

Data Cartridge Not Present before ResetWhen a data cartridge is not present, the CTS responds to the reset asfollows:It returns Check Condition status