Viper 125s Theory Of Operation And Maintenance Manual Download

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Summary of Contents for 125s

Page 1: ...Models 608 1258 and 150S 1 4 lnch Streaming Cartridge Tape Drive Theory of Operation and Maintenance Manual J YE ____________ 1...

Page 2: ...Viper SCSI Models 60S 125S and 150S 1 4 lncl1 Streaming Cartridge Tape Drive Theory of Operation and Maintenance Manual...

Page 3: ...publication may be repro duced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the prior written permission o...

Page 4: ...factor drive The manual contains detailed technical information about Viper SCSI Small Computer Systems Interface tape drives SCSI technology provides a flexible environment by allowing up to eight de...

Page 5: ...al Specifications 2 4 2 6 Data Cartridge Specifications 2 4 2 6 1 Model 60S 2 4 2 6 2 Model 125S 2 5 2 6 3 Model 150S 2 5 2 7 Regulatory Compliance 2 5 2 8 ANSI X3 131 Conformance Statement 2 6 Chapte...

Page 6: ...mand Phase 4 13 4 10 Data Phase 4 13 4 10 1 Data In Phase 4 13 4 10 2 Data Out Phase 4 13 4 11 Status Phase 4 13 4 12 Message Phase 4 13 4 12 1 Message In Phase 4 13 4 12 2 Message Out Phase 4 14 4 13...

Page 7: ...Status 5 7 5 6 REQUEST SENSE 03h 5 S 5 6 1 REQUEST SENSE Command Descriptor Block 5 S 5 6 2 Command Descriptor Block Field Description 5 S 5 6 3 Extended Sense Data Format 5 9 5 6 4 Extended Sense Dat...

Page 8: ...ption 5 30 5 13 3 INQUIRY Command Data Format 5 31 5 13 4 INQUIRY Command Data Field Descriptions 5 31 5 13 5 Completion Status 5 32 5 14 VERIFY 13h 5 33 5 14 1 VERIFY Command Descriptor Block 5 33 5...

Page 9: ...52 5 19 8 2 SEQ to SEQ Segment Descriptor Field Descriptions 5 53 5 19 9 Completion Status 5 54 5 20 ERASE 19h 5 56 5 20 1 ERASE Command Descriptor Block 5 56 5 20 2 Command Descriptor Block Field Des...

Page 10: ...pletion Status 5 73 Chapter 6 Theory of Operations 6 1 6 1 Overview 6 1 6 2 Printed Circuit Board 6 1 6 2 1 Basic VLSI Controller 6 3 6 2 2 Write and Erase Circuits 6 5 6 2 3 Read Circuits 6 6 6 2 4 T...

Page 11: ...e Operation 6 28 6 9 2 Recording 6 28 6 9 2 1 Preamble 6 29 6 9 2 2 Data Block Marker 6 29 6 9 2 3 Data Block 6 29 6 9 2 4 Block Address 6 30 6 9 2 5 Cyclical Redundancy Check 6 31 6 9 2 6 Postamble 6...

Page 12: ...Signal Timing 4 7 Figure 4 4 Signals Used in Transfer from Target to Initiator 4 11 Figure 4 5 Signals Used in Transfer from Initiator to Target 4 12 Figure 6 1 Viper Drive Functional Block Diagram 6...

Page 13: ...n Phase Protocal 4 8 Table 4 6 Informtion Transfer Phases 4 10 Table 4 7 Command Descriptor Block Format 4 14 Table 4 8 CDB Fields Common to group 0 and 1 Commands 4 15 Table 4 9 SCSI Message Codes 4...

Page 14: ...on Phase Protocal 4 8 Table 4 6 Informtion Transfer Phases 4 10 Table 4 7 Command Descriptor Block Format 4 14 Table 4 8 CDB Fields Common to group aand 1 Commands 4 15 Table 4 9 SCSI Message Codes 4...

Page 15: ...apacities Viper drives are available in internal and external models Storage capacity varies from 45 megabytes to 150 megabytes Table 1 1 shows the capacity for each model Table 1 1 Viper Streaming Ta...

Page 16: ...ystems SCSI Bus Viper Computer Host System Adapter Drive SINGLE INITIATOR SINGLE TARGET Computer Host 1 SCSI Bus Viper System Adapter Drive SINGLE INITIATOR MULTI TARGET Magnetic Disk Printer or Optic...

Page 17: ...l drive and its subassemblies Figure 1 3 shows a front view of a Viper external drive BELT DRIVE SYSTEM CAPSTAN DRIVE MOTOR HEAD ACTUATOR MECHANISM MOTOR DRIVER BOARD CAPSTAN ASSEMBLY CHASSIS BEZEL Fi...

Page 18: ...on I Contains guidelines cautions unpacking tips and I inspection information 4 I Interface I Describes the Viper SCSI interface including signals pin assignments and timing 5 Viper SCSI I Individuall...

Page 19: ...ysical Specifications Power Requirements Drive Performance Specifications Environmental Requirements Data Cartridge Specifications Regulatory Compliance SCSI Conformance Statement 2 2 Physical Specifi...

Page 20: ...0 8 Amps nominal 1 1 Amps nominal I 1 7 Amps maximum 1 5 Amps maximum I Tape Start Surge 2 5 Amps maximum i up to 300 msec Power Dissipation 9 6 Watts typical 5 5 Watts typical operational 22 4 Watts...

Page 21: ...pi I I Data Density 8 000 bpi 10 000 bpi 10 000 bpi I i I Data Transfer 90 KB Sec 112 5 KB Sec 112 5 KB Sec I Rate average i Recording Format QIC 24 I QIC 120 QIC 120 or i I I QIC 150 SCSI Burst Data...

Page 22: ...The Viper drives record to maximum capacity when Models 60S and 1255 use DC600A type data cartridges and the Model 1505 uses DC600XTD type data cartridges To enable backward compatibility in all mode...

Page 23: ...3 Model 150S DATA CARTRIDGE DATA ARCHIVE DRIVE FUNCTIONS SPECIFICATION CARTRIDGE MODEL READ WRITE READ ONLY I ANSI BSR X3 127 DC300XLP 545 450 It QIC 24 and QIC 11 format ANSI X3B5 85 138 DC600A 560 6...

Page 24: ...lection of explicit read write format 11 Supports third party reservation 12 Verify is Medium verification only LEVEL 0 1 and 2of ANSI REV 178 OPTIONAL COMMANDS 1 Test Unit Ready B Release Unit 2 Send...

Page 25: ...m the protective packaging discharge static electricity from your body by touching the computers metal surface or any known grounded surface Hold the drive by its edges only touching the printed circu...

Page 26: ...horizontally or vertically as shown in Figure 3 1 Horizontal installation is recommended When vertical mounting is preferred install the drive with the head loading lever at the top as shown Figure 3...

Page 27: ...ctors are located on the back of the drive as shown in Figure 3 3 The recommended interface mating connector is a 3M 3425 6600 Burndy FRE 50BF 1 KEL AM RFM2S 2852 0 or equivalent The recommended power...

Page 28: ...SCSI 10 SERIAL DIAGNOSTIC PARITY ENABLE OPERATION MODE INDICATES JUMPER INSTALLED CF2 CF1 CFO BUFFER SCSI DISCONNECT 100 SIZE 16K Figure 3 4 Configuration Jumper Block 3 5 4 Operational Mode 102 101...

Page 29: ...be sent over the SCSI bus during a single data transfer phase During lengthy data transfers this feature periodi cally frees the bus for other operations thus disconnect size can affect overall syste...

Page 30: ...ors to allow daisy chaining See Figure 3 6 When the Viper is the last drive a single interface cable is attached to one connector and a tenninating plug is installed in the other When the Viper is wit...

Page 31: ...play and set drive identification See Figure 3 6 Push the left button to decrease the number Push the right button to increase the number Other usual features such as disconnect size and parity are se...

Page 32: ...t line The remaining nine lines are for control and status signals to coordi nate data transfer operations between the host controller and the selected drive The Viper drive has an internal SCSI contr...

Page 33: ...argeUlnitiator 14 DB 6 Data Bus Bit6 TargeUlnitiator 16 DB 7 Data Bus Bit 7 MSB TargeUlnitiator 18 DB P Data Bus Parity TargeUlnitiator 20 Ground 22 Ground 24 Ground 25 Open 26 Terminator Power 5V Opt...

Page 34: ...s output from the Initiator MSG Message Target driven signal used to indicate the presence of a Message Phase on the bus True low indicates Message Phase and false high indicates Data Command or Statu...

Page 35: ...VIPER SCSI 60 125 150 THEORY OF OPERATION AND MAINTENANCE 4 4 Command Set Description Table 4 3 shows the SCSI X3 131 Group 0 commands for sequential access devices imple mented by the Viper drive 4 4...

Page 36: ...arget can reselect an Initiator or another Target to continue an operation The Target at times actually becomes an Initiator and arbitrates for control of the SCSI bus For the Viper drive this occurs...

Page 37: ...Phases See ANSI SCSI X1 31 for detailed discussions of bus timing BUS FREE PHASE RESET CONDITION COMMAND DATA SELECTION PHASE I I _ STATUS OR MESSAGE PHASES Figure 4 1 Phase Sequencing with Nonarbltr...

Page 38: ...ase Sequencing with Arbitration SIGNALS Busy BSY Select SEL Data DB 7 0 P Bus Free Phase I I 1 I r l Arbitration ID s ARBITRATION PHASE Initiator ID and Target ID SELECTION PHASE Figure 4 3 Arbitratio...

Page 39: ...Arbitration delay 2 2 j lSec measured after asserting aBSY signal the SCSI device examines the data bus If ahigher priority SCSI 10 bit is true then the SCSI device loses the Arbitration and the SCSI...

Page 40: ...on enters the Selection or Reselection Phases when a particular device wins a request in Arbitration and gains control of the SCSI bus These phases allow the device in control of the bus to select ano...

Page 41: ...Information Transfer Phases use one or more REQ ACK handshakes to control the information transfer Each REQ ACK handshake allows the transfer of one byte of information During the information transfer...

Page 42: ...asserts the REO signal t3 The Initiator reads the data and parity signals after REO is signals its acceptance of the data by asserting the ACK 14 ACK goes low at the Target and the Target deasserts R...

Page 43: ...infor mation 12 The Initiator drives the dala and parily signals to their desired values t3 The Initiator asserts the ACK 14 The Targel deasserts REO signaling its acceptance of data and the Initiato...

Page 44: ...et requests that data be sent from the Initiator to the Target The Target deasserts the C O I O and MSG signals thus denoting the Data Out Phase The REQ ACK handshakes Figure 4 5 then transfers the re...

Page 45: ...by sending a Command Descriptor Block CDB to the Target For several commands the request is accompanied by a list of parameters sent during a Data Out Phase If an invalid parameter is contained in th...

Page 46: ...sage is required value one indicates the Linked Command Complete with Flag message is required Typically the Flag bit is used to cause an interrupt in the Initiator at the end of or at logical interva...

Page 47: ...AINTENANCE 4 14 SCSI Message Descriptions and Definitions The SCSI message codes descriptions and directions are given in Table 4 9 SCSI message definitions are given in Table 4 10 Each of these SCSI...

Page 48: ...Initiator After successfully sending this message the drive goes to the Bus Free Phase by releasing BSY DISCONNECT NOTE The command may have been executed suc cessfully or unsuccessfully as indicated...

Page 49: ...Viper drive to an Initiator to OAh indicate that execution of alinked command is completed and that status was sent The Initiator can then set the pOinters to the initial state for the next linked com...

Page 50: ...the Initiator When the 10 message is completed the Viper drive establishes the Message Out phase in response to Attention being asserted by the Initiator The Viper drive responds to Atten tion at all...

Page 51: ...d and the request function is not done The normal Initiator recovery action is to issue the command at a later time CHECK 1h 02h Any error exception or abnormal condition that CONDITION causes the sen...

Page 52: ...w The Bus Free phase always follows the Reset Condition When a reset is issued to the Viper drive the SCSI bus clears all uncompleted commands releases all SCSI device reservations sets the Viper driv...

Page 53: ...e new com mand with Busy Status An immediate bit of zero means the status is returned to the Initiator when the tape has been repositioned An Immediate bit of one means the status is returned to the I...

Page 54: ...data trapped in the Viper drive buffer not written to tape This is the same quantity as RL AL Actual Length Blocks transferred from the host to the Viper drive across the SCSI bus TL Transfer Length T...

Page 55: ...o select any device on the bus including the drive that initiated the disconnect The drive continuously polls the bus for selection by another Initiator If the Viper drive is selected while disconnect...

Page 56: ...d The set includes Command Status and Data Pointers that point to the Command Descriptor Block Status Area and Data Area respectively for that device The Saved Pointer continues to pOint to the start...

Page 57: ...e error occurs during operation the drive terminates opera tion immediately and returns a Check Condition The Initiator ceases any further read or write functions and issues a Request Sense Command to...

Page 58: ...ble Skew Delay 10 nSec The maximum difference allowed in propagation time between any two SCSI bus signals when measured between any two SCSI bus devices Deskew Delay 45 nSec This time is used to calc...

Page 59: ...nds for Bus Sequential Access Devices CODE COMMAND SECTION OOh TEST UNIT READY 5 3 01h REWIND 5 4 02h REQUEST BLOCK ADDRESS 5 5 03h REQUEST SENSE 5 6 05h READ BLOCK LIMITS 5 7 08h READ 5 8 OAh WRITE 5...

Page 60: ...dent 3 Command Dependent 4 Command Dependent 5 Vendor Unique 0 0 0 0 Flag Link 5 2 2 Command Descriptor Block Field Descriptions The command block descriptor fields are described in the following tabl...

Page 61: ...Flag and Link bits are used by all commands These bits are defined according to the following IF THE LINK BIT IS AND THE FLAG BIT IS THE RESULT IS o The Target sends alinked command complete Ihvvv l I...

Page 62: ...5 3 2 Completion Status ICODE MESSAGE OOh Good Status 02h Check Condition 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o I 0 0 0 o 0 0 I 0 0 0 I FI g1 u DESCRIPTION The tape is not mov...

Page 63: ...oon as the operation is initiated 5 4 3 Completion Status CODE OOh Good Status 02h Check Condition Viper drive is ready to accept any legal command Viper drive remains in any previously set mode The T...

Page 64: ...k on tape is a control block as defined by the QIC 150 specification and the first data block on tape is Block 2 If a REWIND and a REQUEST BLOCK ADDRESS is issued to a QIC 150 tape Block Address 2 is...

Page 65: ...letion Status MESSAGE 02h Check Condition The tape is not moved Viper drive is ready to accept any legal Viper drive remains in any previously set Extended Sense byte 02 DESCRIPTION Parity error on ei...

Page 66: ...e status of the immediately previous command If there is a Check Condition Status a REQUEST SENSE should be issued to recover the information from the Sense Data The REQUEST SENSE command returns Chec...

Page 67: ...d FM Sense Key Residual Residual Length 0 8 COpy Source Sanse Data Pointer j 9 COPY Destination Data Pointer 10 0 R H I I 0 S 11 0 0 12 Number of Recoverable Errors MSB 13 Number of Recoverable Errors...

Page 68: ...rred to Viper Datato tape Data trapped in 192 108 84 Note To recoverdata trappedin the Viper buffer issue a Buffer Data command with Requested Length of84 0 4 6 The Error Class field indicates Extende...

Page 69: ...mber of recoverable errors Soft Errors The 16 bil value is the accumulated soft error count of a series of commands The value in this field is reset to zero when the command is switched from write to...

Page 70: ...n error in the recorded data 04h 2 Hardware Error The Viper drive detected anon recoverable hardware failure parity etc while performing the command 05h 7 Illegal Request The CDS contained an illegal...

Page 71: ...SCSICOMMANDS DESCRIPTION Media Position is not changed Viper drive is ready to perform any appropriate command Viper drive remains in any previously set modes Extended Sense byte 02 MESSAGE DESCRIPTI...

Page 72: ...E 0 0 0 0 0 0 1 0 1 1 1 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 5 X X 0 0 0 0 Flag Link 5 7 2 Command Descriptor Block Field Descriptions There are no command dependent fie...

Page 73: ...pt any appropriate Viper drive remains in previously set mode Extended Sense byte 02 MESSAGE DESCRIPTION Hardware Error Parity error on either the Viper drive Illegal Request The COB contains an WPERS...

Page 74: ...7 6 3 2 1 o BYTE 0 0 0 2 3 4 5 X 5 8 2 Command Descriptor Block Field Descriptions BIT N_A L_B_ITS Fixed Block Size Bit Transfer Length o 2 4 5 8 3 READ command Description DESCRIPTION This bit must...

Page 75: ...e Valid bit is set the Residual Length equals the difference between the requested length and number of actual blocks read 5 8 3 5 Unrecoverable Data Error If an Unrecoverable Data Error is encountere...

Page 76: ...e 03h Media Error Unrecoverable Data Error encountered 04h Hardware Error Parity error either on the Viper drive OSh Illegal Request 06h Unit Attention The cartridge was I h H11 111ri issuing the READ...

Page 77: ...to tape The default after a Reset is the Buffered Mode The Density Code determines the format for writing to or reading from the tape If the tape is written from BOT and the Density Code is default OO...

Page 78: ...t the end of each file prevents this occurrence If an error is encountered while writing 16 attempts are made to rewrite the block If none of the 16 rewrites are successful the error is considered unr...

Page 79: ...e cartridge was changed prior to sending this command The Viper was Reset prior to this commmand 07h Write Protect Tape is write protected check the cartridge before continuing Cartridge in the drive...

Page 80: ...block addresses can in tum be recorded in a user defined directory Typically this directory is located at the end of recorded data and is used to rapidly position to the beginning of specific files o...

Page 81: ...rable data was I encountered i 04h Hardwar rror Parity error on either t CSIBus or I I the Viper drive I OSh Illegal Request The CDB C i nin alidb i Block Count of zero was issued 06h Unit Attention T...

Page 82: ...rks by specifying zero filemarks unless immediate mode is se lected The command does not return Good Status to the Initiator unless all buffered data blocks and filemarks are written correctly on the...

Page 83: ...ot positioned to EOO A OC300XLP is installed the drive cannot write to this media OIC 11 or OIC 24 sent by MODE SELECT the drive does not support writing that density code The cartridge was changed be...

Page 84: ...backward a specified number of Filemarks Forward or backward a specified number of sequential contiguously grouped Filemarks Forward to the end of recorded data A file example is shown below When SPA...

Page 85: ...on ends on the EOT side of the last block or Filemark and reverse motion ends on the BOT side of the last block or Filemark If a Filemark is encountered while spacing over blocks a Check Condition Sta...

Page 86: ...e tape The space to EOD function is useful in support of user defined directories If physical EOT is encountered while spacing to end of data Check Condition Status is returned and Extended Sense is s...

Page 87: ...ive was reset prior to accepting this command 08h Blank Check End of Data was encountered while executing aspace forward 40h EOT bit and BOT was encountered while executing No Sense a Space Reverse 43...

Page 88: ...ondition 5 13 1 INQUIRY command Descriptor Block BITS 7 6 5 4 3 2 1 0 BYTE _ _ 0 0 0 0 1 0 0 1 0 1 0 0 0 0 0 0 0 0 _ 2 0 0 0 I 0 0 0 0 0 3 0 0 0 0 0 0 0 0 4 Allocation Length 5 X X 0 0 0 0 Flag Link 5...

Page 89: ...Data Field Descriptions FIELD I NAME BYTE Peripheral 0 Device Type RM BIT 0 7 7 5 31 DESCRIPTION This field indicates asequential access device Value 7Fh indicates that a logical unit is not present...

Page 90: ...nltU uOllUI Length in the COB is too small to accommodate entire These fields contain eight bytes of ASCII data These fields contain sixteen bytes of ASCII data VIPER 150 XXXXX for the Viper firmware...

Page 91: ...edium is positioned after the last block verified or Filemark If a VERIFY with a zero verification length is issued no data is verified and the current position on the tape does not change This condit...

Page 92: ...orted in bytes 13 and 14 of the Request Sense Data I All data is successfully io2h No t Re a d y _ _ r i aisenotinstalled in I the drive 03h Media Error An unrecoverable was encountered _ _ 04h Hardwa...

Page 93: ...One or more RECOVER BUFFERED DATA commands may be used to read the unwritten buffered data 5 15 2 Command Descriptor Block Field Descriptions FIELD NAME Fixed Block Size Bit Transfer Length o 2 4 0 7...

Page 94: ...de Extended Sense byte 02 CODEIMESSAGE I DESCRIPTION 02h 04h 05h 06h 40h 5 36 Not Ready Acartridge is not installed in the drive Hardware Error Parity error on either the SCSIBus or the Viper drive Il...

Page 95: ...a cartridge installed or when positioned away from BOT with a cartridge installed 5 16 2 Command Descriptor Block Field Description FIELD NAME BYTES DESCRIPTION Parameter List Length 4 5 16 3 Paramete...

Page 96: ...e Viper drive buffer In the Unbuffered Mode Viper drive does not report Good Status on a Write command until the data is successfully written to Tape The Speed Field must be set to zero to indicate th...

Page 97: ...tations are shown in the following table Implicit Mode determine the format on the installed tape The search order is Format QIC 150 QIC 24 QIC 11 In aWRITE Operation the drive determines the cartridg...

Page 98: ...ormats are terminated with aCheck Condition and aSense Key of Blank Check WRITE In Write Operation the drive only writes in the selected Explicit Mode If the installed cartridge does not support the s...

Page 99: ...Sense byte 02 __1 CODE I MESSAGE DESCRIPTION 04h Hardware Error Parity error on either the SCSI Bus or the Viper drive OSh Illegal Request The CDB or Parameter List contained an invalid bit The Buffe...

Page 100: ...The new reservation supercedes the current one and may be the same as the current one Redundant use of the command is not considered an error A RELEASE UNIT command arrives from the same Initiator th...

Page 101: ...reservation if this field does not identify the Initiator currently in control of the Viper drive DESCRIPTION The position of the Media is not changed Viper drive is ready to accept any appropriate c...

Page 102: ...scussed under the RESERVE UNIT command NOTE It is nDt an error to attempt to release an 10 that is not currently reserved to the requesting Initiator Areservation cannot be released if it is reserved...

Page 103: ...ins in any previously set mode Viper drive accepts commands from any Initiator 02h Check Condition Extended Sense byte 02 CODEiMESSAGE I DESCRIPTION 04h Hardware Error Parity error on either the SCSIB...

Page 104: ...ng the 4 byte Header plus all 12 byte Segment Descriptors The Parameter List Length must be divisible by the 12 byte Segment Descriptor plus 4 byte header Examples of valid quantities are 01 41 161 28...

Page 105: ...g a WRITE or READ command the Viper determines the block size of the D A device and the number of blocks to be transferred and converts this to 512 byte block intervals for the Viper drive to complete...

Page 106: ...opy to itself In the following Segment Descriptors designation ofSCSI ID for a Viper drive must match the SCSI ID configured on the Viper drives Configuration Jumper Block 5 19 6 D A to SEQ Segment De...

Page 107: ...ress 11 DIADevice Logical Block Address LSB 5 19 6 2 DIA to SEQ Segment Descriptor Field Descrigtions FEATURE I BYTES BITS DESCRIPTION Source SCSIID 0 5 7 This field specifies the source SCSIID of the...

Page 108: ...a WRITE type command to be issued to the 0 A device with a Transfer Length of zero This is not considered an error This type of WRITE command is a function of the value in 0 A Device Logical Block Add...

Page 109: ...COPY Function Code 03h the managing Viper drive may be either the source or destination device The LUN associated with a Viper drive must always have value 0 referencing the controller s single drive...

Page 110: ...8 1 SEQ to SEQ Segment Descriptor Block BITS 7 6 5 4 3 2 1 BYTES o Source SCSIID o o Source LUN 3 0 0 0 0 0 0 0 0 4 Source Block Length MSB 5 Source Block Length LSB 6 Destination Block Length MSB 7 D...

Page 111: ...N Destination SCSI 10 lUN Source Block Length Destination Block Length of o 4and 5 6and 7 8to 11 0 2 5 7 5 53 This field specifies the source LUN numberof the SEQ device This field specifies the desti...

Page 112: ...r size is not configured for the minimum 16K Host does not support DisconnecUReconnect The Viper drive is not LUN 0 Segment descriptor has a bit incorrectly set Target block size is 2S6K Segment Descr...

Page 113: ...was the source byte 8ot the Request Sense Extended Sense is set to 06h and byte 9is set to OOh It the target was the destination byte 9of the Request Sense Extended Sense is set to 05h byte 8is set t...

Page 114: ...TE 0 0 0 0 1 1 0 0 1 1 I 0 0 0 0 0 0 IMMED Long 2 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 4 0 0 I 0 0 0 0 0 0 5 X X 0 0 0 0 5 20 2 Command Descriptor Block Field Descriptions Long o 5 56 The Long Bit specifie...

Page 115: ...GE DESCRIPTION 02h Not Ready No cartridge in drive 04h Hardware Error Parity error either on the SCSI Bus or the Viper drive 05h Illegal Request Both JMMED bit and Link bit were set to 1 The cartridge...

Page 116: ...TS I DESCRIPTION 4 This byte specifies the number of bytes the Viper drive returns in the Data In Phase An Allocation Length of zero means no MODE SENSE data is transferred This condition is not consi...

Page 117: ...ether or not the tape is write protected aone indicates write protected azero indicates write enabled In Unbuffered Mode the Viper drive does not report Good Status on a WRITE command until the data h...

Page 118: ...es in a READ command Density Codes and Interpretations are shown 10h QIC 150 5 21 5 2 Implicit Mode Default Density Code Mode In READ Operation the drive does a fonnat search at BOT to detennine the f...

Page 119: ...command terminates with a Check Condition and a Sense Key of 05h Illegal Request or 07h WRITE Protect If the Selected DenSity Mode is a 04h or OSh in a 125S or a 150S the write operation terminates w...

Page 120: ...set mode MODE SENSE does notsetorchange any modes Viper drive is ready to perform any appropriate Extended Sense byte 02 I cODETMESSAGE i DESCRIPTION 1 04h Hardware Error Parity error on either the S...

Page 121: ...OT the tape positions at BOT and the cartridge may be removed at BOT without an error condition 5 22 1 LOAD UNLOAD Command Descriptor Block IMMED Bit 4 RETEN Bil 5 63 This bit specifies that status is...

Page 122: ...m any appropriate commands Media is positioned to BOT then to EOT then back to BOT After this action the tension on the tape is equalized from BOT to EOT and any errors caused by poor tape tension sho...

Page 123: ...I 1 f1 BYTE i 0 i 1 0 0 i 0 0 1 1 1 1 1 I 0 0 0 0 0 1 o 0 0ct8 2 0 0 0 0 0 0 I 3 0 0 0 0 0 0 0 0 0 0 0 0 0 j 4 i i 0 0 0 I 5 i x I x 0 0 i 0 0 I I i i 5 23 2 Command Descriptor Block Field Description...

Page 124: ...nse byte 02 rc DE 1ESS GE I DESCRrPTIO _ 02h Not Ready A cartridge is not installed in the drive 04h Hardware Error Parity error on either the SCSI Bus orthe Viper drive the diagnostic failed OSh Ille...

Page 125: ...D is OFF no Unit Attention is set If the PREVENT command is issued the LED is always ON even at BOT and then media removal even at BOT causes the Unit Attention Condition to be set After a Reset the d...

Page 126: ...nd the Unit Attention Condition is set upon media removal If an ALLOW command was sent the LED goes out at BOT This allows media removal at BOT without setting Unit Attention Condition Check Condition...

Page 127: ...UFFER Command as a diagnostic function for testing the data buffer memory of the Viper drive and confirming the SCSI bus integrity There is no access to the medium during the execution of this command...

Page 128: ...followed by the Write Data Buffer data All transactions must be in multiples of 512 bytes fixed block length plus a4byte header A Byte Transfer Length of zero indicates that no WRITE DATA BUFFER heade...

Page 129: ...k Condition Extended Sense byte 02 I CODE MESSAGE DESCRIPTION 02h Not ready Acartridge is not installed in the drive 04h Hardware Error Parity error on either the i SCSIBus or the Viper drive 05h Ille...

Page 130: ...DATA BUFFER Command Descriptor Block 1 o 3 4 5 6 7 Allocation Length MSB 8 Allocation Length LSB 9 X Link 5 26 2 Command Descriptor Block Field Description Allocation Length BYTE 7and 8 o 5 72 this bi...

Page 131: ...e header In that case the drive returns the requested length including the four byte header If the number of bytes specified in the Allocation Length exceeds the Available Length plus 4 or is not modu...

Page 132: ...ng area and contains LSI circuits to control the speed and direction of the capstan drive motor SCSI control signals are transmitted to and from the Viper via the host interface connector at the rear...

Page 133: ...64 ADDRESS BUS RST MICRO i t PROCESSOR I CONTROL 8031 PHASE LOCK LooP CIRCUIT READ CIRCUIT WRITEiERASE CIRCUIT DRIVE MOTOR CARTRIDGE IN AND SAFE MICROSWITCH RST EPROM 27512 L _________________________...

Page 134: ...zed with a reset signal The status bits can be read by the microprocessor at any time regardless of mask bit settings The memory access controller consists of the arbiter memory address multiplexer me...

Page 135: ...is between two rising edges of the clock signal The separated data and clock signals applied to the read controller The read alter write signal controls the data window size It narrows down the data w...

Page 136: ...1 When REV goes high and WEN is high 12 volts is applied to Head O When recording to track 0 an erase current at 2 8 megahertz is applied to the full width erase head through gates and signals ERA an...

Page 137: ...ated into the read comparator zero crossing detector and write comparator threshold detector circuits The threshold detector is triggered with 25 amplitude or 4 amplitude depending upon whether the dr...

Page 138: ...wo signals AQA and TRKA These signals represent the two modes of operation frequency lock acquire and frequency phase Iock tracking When operation begins the system is in the frequency lock acquire mo...

Page 139: ...ta as it is written The difference between only reading data or reading after writing is controlled by the VLSI microprocessor and the host The read after write data is qualified by the read and write...

Page 140: ...host are interrupted an underrun occurs If data transfers from the host are under 90 kilobytes per second the tape will not stop but the drive may at intervals write a duplicate of the preceding data...

Page 141: ...me is linked to the front panel latch lever so the assembly is pivoted in and out of position as the cartridge is latched or unlatched A leaf spring stop provides accurate and precise location of the...

Page 142: ...ion to the drive circuitry for switching the motor driver transistors at the correct times to assure proper speed and rotational direction Capstan pressure is provided by mounting the capstan and bear...

Page 143: ...a mirror back through the window in the cartridge onto two infra red detectors adjacent to the LED Normally the beam is blocked by the tape as it moves across the head Near each end of the tape are sm...

Page 144: ...running at speed 0 motor stopped motor stalled When the host asserts the GO signal the Viper drive controller deasserts the STPD signal and starts the motor in the direction specified by the REV signa...

Page 145: ...cers control all activity within the motor driver LSI The host sequencer is the main sequencer it interprets control information from the host computer reporting status to the host computer and contro...

Page 146: ...an be shifted only to the right in this register Width Modulator The pulse width modulator generates pulses based on a value loaded Commutation Logic Shift Counter sequencers The pulse width modulator...

Page 147: ...pe interface Constructed of carefully selected and matched materials and finished to a smoothness of a few millionths of an inch the ceramic head provides optimum reliability and durability User servi...

Page 148: ...the required numberofelectronicallycalculated steps to a designated track Precise positioning of the head assembly is essential to assure media interchangeability from one drive to another The Viper...

Page 149: ...they are written in bit serial one track at a time Figure 6 6 When the load point hole is detected on the tape the head is in the recording zone and writing begins on track O In addition to writing o...

Page 150: ...ite direction in search for the end of tape Early Warning hole which now will be the load point for track 1 Writing is then enabled when the end of tape Early Warning hole is reached When the beginnin...

Page 151: ...ill 12 ill 2 4 6 10 ill 8 ill o BEGINNING OF MEDIA 4 4 END OF MEDIA 4 14 Figure 6 9 Serpentine Recording Pattern 1S Track 13 15 5 1 3 11 7 9 17 END OF MEDIA 12 ill 2 4 6 4 10 ill 8 ill o BEGINNING OF...

Page 152: ...d during the read check that block is rewritten During the Write Command the three buffers are allocated as follows one for the block being written one for the block being read checked so the data is...

Page 153: ...or in Block N 7 Because a CRC error was found block N must be rewritten Block N 1 is already half written 8 The drive finishes writing block N 1 then begins writing block N a second time 9 If no error...

Page 154: ...correct tape speed and begins writing new data after the gap This underrun procedure allows about 3 33 mSec at 90 ips of delay for the host to catch up to the drive before tape motion is interrupted...

Page 155: ...ormed Successful soft error retries are invisible to the host The Viper drive controller logs all soft error retries and passes the count to the host 6 8 5 Streaming Termination The tape streaming ope...

Page 156: ...AMBLE _OVERLAP ELONGATED PREAMBLE Rewritten Blocks When recording on tape some blocks may have to be rewritten further down the tape This is done to decrease the system error rate Ablock Nmay be recog...

Page 157: ...linder the write head is either disabled or enabled so data on the tape cannot be overwritten The tape and transport mechanism are protected by aclear plastic case which contains an access door that i...

Page 158: ...SENSE MIRROR WRITE LOCKOUT PLUG CORNER ROLLER DRIVE ROLLER DRIVE BELT CORNER ROLLER PIN WRAP PIN I 1 TAPE GUIDE BASE PLATE I i e I o DOOR DRIVE ROLLER PIN WRAP PIN TAPE GUIDE Figure 6 12 Data Cartrid...

Page 159: ...I DESCRIPTION Capstan Belt Drive The drive motor is mounted near the rear of the drive and connected to the capstan by abelt Belt tension is factory set with controlled pulley to pulley distances One...

Page 160: ...ed preamble precedes the first data block recorded after an underrun conditions occurs The long preamble precedes the first data block for interchange recorded at the beginning of atrack 6 9 2 2 Data...

Page 161: ...ent blocks are numbered sequentially The block number is reset at the end of a track The track number is recorded in Byte O NIBBLE GCR EQUIVALENT HEX B3 B2 B1 BO G4 G3 G2 G1 GO HEX Oh 0 0 0 0 0 0 19 h...

Page 162: ...ytes of interchange data and the 4 byte block address starting with all ones CRC initial value The CRC is encoded into GCR bytes in accordance with Table 6 2 The CRC is generated using the following p...

Page 163: ...00 12 500 12 500 Bit Cell Width ulnch 100 80 80 Tracks 9 15 18 Format Preamble Flux Trans Normal 120 300 160 300 160 300 Elongated 3 500 7 000 3 500 8 500 3 500 8 500 Long 15 000 30 000 15 000 30 000...

Page 164: ...onitor or any peripheral device When not in use store a cartridge in its protective box away from heat sources and electromagnetic fields When a stored tape is moved to an environment with a greatly d...

Page 165: ...ge and turn OFF power to the computer 2 Push the head loading lever to LOAD position toward the cartridge cavity opening to position the heads into an accessible position for cleaning 3 Carefully blow...

Page 166: ...me To Repair MTTR is the average time required by a qualified service techni cian to diagnose a defective drive and install a replacement drive Viper reliability specifications are listed in the follo...

Page 167: ...ve to report a problem Be pre pared to describe the problem by answering these questions What function such as formatting backup or restoring was in progress when the problem occurred What error messa...

Page 168: ...the use of a processor or try to access the system bus at the same time DEFAULT A preset value used by a program if no other value is specified DISCONNECT The action of a target releasing control of...

Page 169: ...nstallation and connection SERPENTINE The winding logical pattern that results when the streaming tape drive records data on the tape SOFT ERROR Is a repeated attempt by the tape drive firmware to rea...

Page 170: ...6 4 8 4 27 Bus free phase 4 6 4 8 4 17 4 21 4 24 4 27 Bus settle delay 4 6 4 8 through 4 10 4 27 Byte Counter 6 4 Cable skew 4 27 Capacities 1 1 Capstan Belt Drive 6 28 Cartridge Components 6 25 6 26...

Page 171: ...2 Interrupt Controller 6 3 Jumper configuration 3 4 1 2 Load command 4 21 5 41 5 57 5 62 through 5 64 Load unload 2 6 4 4 5 1 5 63 Loading Mechanism 6 10 Logical unit number 4 14 4 15 4 18 5 02 LUN 4...

Page 172: ...6 16 Sequential access devices 4 4 5 1 Shift Counter 6 15 Signal Descriptions 4 3 Signal Notation Conventions 4 1 Space 2 6 4 4 4 25 5 1 5 10 5 19 5 26 through 5 29 5 32 5 73 Specification 1 4 2 1 th...

Page 173: ...J yE 1650 Sunflower Avenue Costa Mesa CA 92626 714 641 0279 Telex 4722063...

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Viper 125s, Theory Of Operation And Maintenance Manual

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