IBM 3480 Service manual

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IBM 3480 Magnetic Tape Subsystem Storage
User's Reference Subsystem
Library
GC35-0099-3

Fourth Edition (November 1987)
This is a revision of and makes obsolete GC35-0099-2.
Changes or additions to the text or illustrations will be indicated
by a vertical line to the left of the change.
References in this publication to IBM products, programs, or
services do not imply that IBM intends to make these available in
all countries in which IBM operates. Any reference to an IBM
licensed
program in this publication is not intended to state or
imply that only IBM's licensed program may be used. Any
functionally equivalent program may be used instead.
Publications are not stocked at the address given below.
Requests for IBM publications should be made to your IBM
representative or to the IBM branch office serving your locality.
A form for
reader's comments is provided at the back of this
publication. If the form has been removed, comments may be
addressed
to IBM Corporation, General Products Division,
Department 61C, Tucson, Arizona, U.S.A. 85744. IBM may use or
distribute whatever information you supply in any way it believes
appropriate without incurring any obligation to you.
© Copyright International Business Machines Corporation 1984,
1986, 1987

Preface
Organization
This manual gives programmers information about using the IBM 3480
Magnetic Tape Subsystem. For complete information about specific macros,
commands,
or functions, consult the other manuals listed in "Related
Publications."
This manual contains the following:
• "Chapter 1. Introduction," gives an overview ofthe IBM 3480 Magnetic
Tape Subsystem and the software requirements for the 3480
• "Chapter 2. Tape Characteristics," describes the format of an IBM
standard data set label
• "Chapter 3. Modifying Existing Code," describes the changes to code
that are needed to use the 3480 including DCB parameters, JCL
changes, and modifications to JFCB
• "Chapter 4. Controlling the I/O Device," describes the changes to the
NOTE, POINT, and DEVTYPE macros, as well as the new SYNCDEV
macro
• "Chapter 5. Displaying Messages," describes the new MSGDISP macro
that allows messages to be displayed to the operator
• "Chapter 6. Managing and Controlling Data Sets," describes the
changes for DFHSM when using the 3480
• "Chapter 7. Recording Error or Statistical Information," describes how
to use the 3480 for the IMS/VS log tape and error and statistical
information
• "Chapter 8. Restrictions to Using Sorting Applications," describes the
restrictions to DFSORT when using the 3480
• "Appendix A. Data Control Block Symbolic Field Names," describes the
control block fields
• "Appendix B. Checkpoint/Restart Codes," shows the return and
completion codes for the IBM 3480 Magnetic Tape Subsystem when
taking a checkpoint.
Preface 111

Prerequisite Knowledge
To use this book effectively, you should already understand data
management procedures.
Related Publications
You may want to reference information presented in the publications listed
below.
IBM 3480 Magnetic Tape Subsystem
• IBM 3480 Magnetic Tape Subsystem Introduction, GA32-0041
• IBM 3480 Magnetic Tape Subsystem Planning and Migration Guide,
GC35-0098
• IBM 3480 Magnetic Tape Subsystem Reference: Channel Commands,
Status and Sense Bytes, and Error Recovery Procedures, GA32-0042
• IBM 3480 Magnetic Tape Subsystem Operator's Guide, GA32-0066
• Care and Handling of the IBM Magnetic Tape Cartridge, GA32-0047
• IBM Input/Output Equipment: Installation Manual-Physical Planning
for System/360, System/370,
and 4300 Processors, TNL GN22-2317 to
GC22-7064
• Tape and Cartridge Requirements for the IBM 3480 Tape Drives,
GA32-0048.
MVS/Extended Architecture
• MVS/Extended Architecture Checkpoint/Restart User's Guide, GC26-4139
• MVS/Extended Architecture System-Data Administration, GC26-4149
• MVS/Extended Architecture Data Administration Guide, GC26-4140
• MVS/Extended Architecture Data Administration: Macro Instruction
Reference, GC26-4141
• MVS/Extended Architecture Magnetic Tape Labels and File Structure
Administration, GC26-4145
• MVS/Extended Architecture Message Library: System Messages,
Volumes 1 and 2, GC28-1376 and GC28-1377
• MVS/Extended Architecture Message Library: System Codes, GC28-1157
IV IBM 3480 Magnetic Tape Subsystem User's Reference

• MVS/Extended Architecture, MVS/System Product-JES3 Version 2,
MVS/System Product-JES2 Version 2, LIC PROG 5665-291, 5740-XC6,
Routing and Descriptor Codes, GC28-1194
• MVS/Extended Architecture Installation: System Generation, GC26-4148
• MVS/Extended Architecture Data Facility Product: General
Information, GC26-4142
• MVS/Extended Architecture Conversion Notebook: MVS/System Product
JES2,
LIC PROG 5740-XC6; MVS/System Product JES3, LIC PROG
5665-291, GC28-1143
• MVS/Extended Architecture, MVS/System Product-JES3 Version 2,
MVS/System Product-JES2 Version 2, LIC PROG 5665-291, 5740-XC6,
Job Control Language, GC28-1148
• MVS/Extended Architecture MVS/System Product Version 2 5665-291
5740-XC6, Initialization and Tuning, GC28-1149
• MVS/Extended Architecture, MVS/System Product Version 2-JES3
MVS/System Product Version 2-JES2, LIC PROG 5665-291, 5740-XC6,
Supervisor Services and Macro Instructions, GC28-1154
• MVS/Extended Architecture MVS/System Product-JES3 Version 2,
MVS/System Product-JES2 Version 2, LIC PROG 5665-291, 5740-XC6,
System Macros and Facilities,
Volumes 1 and 2, GC28-1150 and
GC28-1151
• MVS/Extended Architecture, LIC PROG 5665-291, 5740-XC6, System
Modifications, GC28-1152
• MVS/Extended Architecture, MVS/System Product-JES3 Version 2,
MVS/System Product-JES2 Version 2, 5665-291, 5740-XC6, System
Management Facility, GC28-1153
• MVS/Extended Architecture, MVS/System Product-JES2 Version 2,
5740-XC6 Operations: JES2 Commands, SC23-0064
• MVS/Extended Architecture, MVS/System Product JES2 Version 2, LIC
PROG 5740-XC6, Initialization and Tuning, SC23-0065
• MVS/Extended Architecture, MVS/System Product-JES3 Version 2,
LIC PROG 5665-291, Operations: JES3 Commands, SC23-0063
• MVS/Extended Architecture System, MVS/System Product-JES3
Version 2, LIC PROG 5665-291, Initialization and Tuning, SC23-0059
• MVS/Extended Architecture Debugging, MVS/System Product-JES3
Version 2, MVS/System Product-JES2 Version 2,5665-291, 5740-XC6,
Preface V

MVS/370
Handbook, Volumes 1 through 5, LC28-1l64,1 LC28-1l65, LC28-1l66,
LC28-1l67
and LC28-1l68.
• MVS/370 Data Facility Product, 5665-295, Checkpoint/Restart, GC26-4054
• MVS/370 Data Facility Product, 5665-295, System Generation Reference,
GC26-4063
• MVS/370 Data Facility Product, 5665-295, Data Management Macro
Instructions, GC26-4057
• MVS/370 Data Management Services, Data Facility Product 5665-295,
GC26-4058
• MVS/370 Data Facility Product, 5665-295, Data Management, GC26-4056
• MVS/370 Magnetic Tape Labels and File Structure, 5665-295, GC26-4064
• MVS/370 Message Library: System Messages, Volumes 1 and 2,
GC28-1374 and GC28-1375
• OS/VS Message Library: System Codes, GC38-1008
• OS/VS Message Library: VS2 Routing and Descriptor Codes, GC38·1102
• MVS/370 Installation: System Generation, GC26-4166
• MVS JCL MVS/System Product-JES2 Release 3.3, MVS/System
Product-JES3 Release 3.1, LIC PROG 5740-XYS, -XYN, GC28-1300
• MVS/370 Data Facility Product: General Information, GC26-4160
• OS/VS2 System Programming Library: Debugging Handbook,
MVS/System Products, LIC PROG 5740-XYN, -XYS, Volumes 1 through
3, GC28-1047, GC28-1048, and GC28-1049
• OS/ VS2 MVS Supervisor Services and Macro Instructions, GC28-0683
• OS/ VS2 MVS System Programming Library: Initialization and Tuning
Guide, GC28-0681
• OS/VS2 MVS System Programming Library: Supervisor, GC28-0628
• OS/VS2 MVS System Programming Library: System Management
Facilities, GC28-1030.
All five volumes may be ordered under one order number, LBOF-I015.
VI IBM 3480 Magnetic Tape Subsystem User's Reference

VMjSP and VMjHPO
VSEjSP
• Virtual Machine/System Product Planning Guide and Reference,
SC19-6201
• Virtual Machine/System Product High Performance Option Planning
Guide
and Reference, SC19-6223.
• IBM Virtual Storage Extended/System Package Hardware and Software
Support Extensions, Version 2 Release
1, SC33-6184.
Other Related Publications
• OS/VS Sort/Merge Programmer's Guide Program Product 5740-SM1,
SC33-4035
• Data Facility Hierarchical Storage Manager: Version 2 Release 3.0
Installation and Customization Guide, SH35-0084
• Data Facility Hierarchical Storage Manager: Version 2 Release 3.0
System Programmer's Guide, SH35-0085
• Data Facility Hierarchical Storage Manager: Version 2 Release 3.0
System Programmer's Reference Guide, SH35-0083
• OS/VS2 MVS and Stand-Alone Versions: Input/Output Configuration
Program,
LIC PROG 5740-XYN, -XYS, User's Guide and Reference,
GC28-1027
• Environmental Recording Editing and Printing (EREP) Program,
GC28-1178
• Data Facility/Data Set Services, LIC PROG 5740-UT3, User's Guide and
Reference, SC26-3949
• IBM Input/Output Equipment: Installation Manual-Physical Planning
for System/360, System/370, and
4300 Processors, GC22-7064
• IBM System/370 Installation Manual: Physical Planning, GC22-7004.
Preface Vll

Contents
Chapter 1. The IBM 3480 Magnetic Tape Subsystem ........... 1
IBM
3480 Magnetic Tape Subsystem Operating Mode ............... 2
Conventions Used ........................................... 3
Chapter 2. Tape Characteristics .......................... 5
Changed Format of IBM Standard Data Set Label 2 (HDR2/EOV2/EOF2) 5
Chapter 3. Modifying Existing Code in MVS Systems .......... 7
Selecting Data Set Options .................................... 7
DCB
Parameters .......................................... 7
Coding
the Block Size and Logical Record Length Operands ........ 8
Constructing a Data Control Block ........................... 8
Specifying JCL Options ...................................... 9
Modifying
the Job File Control Block (JFCB) ..................... 9
Setting the Header Label Block ID in the JFCB for High·Speed
Search ................................................ 10
Example of How to Code OPEN(J) ........................... 11
MVS Block Count Checking .................................. 12
User Exits .............................................. 13
EXCP Routines .......................................... 13
User Programs .......................................... 14
Performance Options for IEBGENER ........................... 15
IEBGENER Storage Requirements ........................... 15
Chapter 4. Controlling the 110 Device ..................•.. 17
Controlling High-Speed Search (NOTE/POINT) ................... 17
How the Physical Block Identifier Works ...................... 17
Retrieving the BLOCKID .................................. 17
Performing the High-Speed Search ........................... 18
Comparing
Conventional Search and High-Speed Search .......... 19
Examples of How to Code NOTE and POINT ................... 20
NOTE-Provide Relative Position (BPAM and BSAM) ............ 22
Completion Codes from NOTE .............................. 23
POINT -Moving Tape to a Relative Block Position (BP AM and
BSAM) ............................................... 23
Completion Codes from POINT .............................. 25
Controlling Data Synchronization (SYNCDEV) ................... 25
Example of How to Code SYNCDEV ......................... 27
SYNCDEV-Synchronize Device ............................. 28
SYNCDEV-List Form .................................... 29
SYNCDEV-Execute Form ................................. 30
Completion Codes from SYNCDEV ........................... 31
Obtaining I/O Device Characteristics (DEVTYPE) ................. 32
Contents IX

Chapter 5. Displaying Messages (MSGDISP) •••.•...••.•••.• 33
Displaying a Message from any User Program (MSGDISP RDY) ...... 33
Example of How to Code MSGDISP RDY ...................... 34
MSGDISP-Displaying a Ready Message ...................... 35
,MSGDISP-Displaying a Ready Message List Form ........... l... 36
MSGDISP-Displaying a Ready Message Execute Form ........... 37
Displaying a Message from Authorized Programs .................. 38
MSGDISP-Displaying a Mount Message ...................... 39
MSGDISP-Displaying a Verify Message ...................... 42
MSGDISP-Displaying a Demount Message .................... 46
MSGDISP-Resetting the Message Display ..................... 50
MSGDISP-Providing the Full Range of Display Options .......... 53
Return Codes from MSGDISP ............................... 57
Modifying MSGDISP for Other Languages ....................... 58
Chapter 6. Managing and Controlling Data Sets .•....••.•••. 61
Specifying Esoteric Unit Names ............................... 61
Recycling Tapes ........................................... 61
Establishing or Changing the Values of DFHSM Control Parameters
(SETSYS) ............................................... 62
Specifying the Tape Density When Allocating Scratch Tapes
(DENSITY)
............................................ 62
Specifying the Type of Unit for Mounting a Scratch Tape
(UNITNAME) .......................................... 62
Specifying Esoteric Tape Unit Name to DFHSM
(USERUNITTABLEINOUSERUNITTABLE)
.................. 63
Adding or Changing the Volumes Managed by DFHSM (ADDVOL) 64
Specifying the Type of Device (UNIT) ........................ 64
Specifying the Tape Density (DENSITY) ...................... 65
Chapter 7. Recording Error or Statistical Information .......•. 67
Using EREP Reports ........................................ 67
Using Error Recovery Procedures (ERP) ........................ 67
Using IMS/VS Logging ...................................... 67
Chapter 8. Restrictions to Using Sorting Applications (DFSORT) 69
SORTWKnn DD statement ................................... 69
SORTOUT DD Statement .................................... 69
Appendix A. Data Control Block Symbolic Field Names ........ 71
Magnetic Tape Interface ..................................... 72
Appendix B. Programming Messages and Codes •.•..••.•..•• 73
Return Code from the CHKPT Macro Instruction for the 3480 ........ 73
ABEND Completion Codes Issued by Checkpoint/Restart for the 3480 .. 73
ABEND Return Codes ...................................... 73
Glossary .•..•.••.•.•••....•.........•..............• 75
Index ............................................... 79
x IBM 3480 Magnetic Tape Subsystem User's Reference

Figures
1. JFCB Layout ......................................... 11
2. Sample Message Display Language Modification .............. 58
3. Description of CSECT IGXMSGOI ......................... 59
Figures Xl

Summary of Amendments
IBM 3480 Magnetic Tape Subsystem User's Reference
Release GC35-0099-3, July 1987
This edition includes changes to correct errors or omissions in the previous
edition.
Release GC35-0099-2, January 1987
This edition adds information on the 3480 Model All Control Unit and
Model Bll Tape Drive.
There are also miscellaneous changes to correct errors or omissions in the
previous edition.
Release GC35-0099-1, July 1986
This edition incorporates Technical Newsletter number GN35-0319 and adds
information on the Automatic Cartridge Loader Feature.
Summary of Amendments XUl

Chapter 1. The IBM 3480 Magnetic Tape Subsystem
The IBM 3480 Magnetic Tape Subsystem consists of a 3480 Control Unit,
Model All or A22, and up to four 3480 Tape Units, Model Bll or B22. Each
tape unit contains two magnetic tape drives. With a Dual Control Unit
Communications Coupler feature, two control units can be connected to
allow mutual control of eight tape units (16 drives). The Automatic
Cartridge Loader feature, which allows both the automatic loading of
premounted tape cartridges and the manual loading of single tape
cartridges, can be added to any or all of the tape units. With additional
channel attachment features, each control unit can connect with up to four
channels.
The subsystem can read and write data at rates up to three megabytes per
second. This high data rate is achieved by recording 18 data tracks at a
linear data recording density of about 38000 bytes per inch.
The control unit contains a buffer that stores the data being transferred
between the tape drive and the controlling processor. The buffer reduces
delays in the operations of the processor that are normally caused by the
start and stop actions of individual drives. Because of the buffer, blocks of
data to be written are transferred to the control unit before the tape drive
is ready to accept them. The channel is then released to do other work
while the data transfers from the control unit to the tape drive. During
reading, data is transferred from the tape drive to the control unit buffer so
as to be available when the controlling processor requests it.
Because the 3480 subsystem indicates that the writing action is complete as
soon as the write data has been transferred to the buffer, the subsystem also
provides a tape-write-immediate mode of writing data to tape.
Tape-write-immediate mode forces
the subsystem to write the data on the
tape before it indicates that the action is complete. Tape-write-immediate
mode
should be used only when the data is critical because this mode
reduces subsystem performance.
The 3480 subsystem provides a high-speed search function. With high-speed
search, you can search for specific blocks on the tape (with the subsystem
disconnected from the channel) at much higher speed than is used for
reading and writing. When the block is found, the subsystem reconnects to
the channel to signal that it is ready for the next command.
Each tape drive has a message display on its operator's panel. The
messages on this display can keep the operator informed of the status of the
tape drive. In an MVS system, the program can write any necessary
messages to the drive message display.
Chapter 1. The IBM 3480 Magnetic Tape Subsystem 1

The tape drives can be assigned to specific channels by program action.
This assignment
ability replaces the mechanical switching used for channel
assignment for earlier tape drives. For more information on channel
assignment, see IBM 3480 Magnetic Tape Subsystem Planning and
Migration Guide.
IBM 3480 Magnetic Tape Subsystem Operating Mode
In MVS systems, the 3480 subsystem can operate as a 3480 in full function
mode,
or it can operate in 3420 compatibility mode. System generation
controls the mode in which the 3480 operates. Both the 3480 in full
function mode and the 3480 in 3420 compatibility mode cannot both be
generated at the same time on the same system. If you are generating
a 3480 in full function mode, you cannot generate compatibility mode for
any other 3480s on the system. However, catalog entries for both the 3480
and the 3420C are synonymous, and both entries can exist in the same
catalog. This allows you
to share catalogs among systems or migrate to a
full function
3480 without changing catalog entries. Each system uses the
catalog entry appropriate to the 3480 device type that was generated on
that system. VM and VSE/SP support for the 3480 is comparable to that
provided in MVS compatibility mode. i
When the 3480 is operating in compatibility mode, the following 3480
features are supported:
• Tape write-immediate mode (OPT CD = W)
• Full error recovery (ERP) support
• Buffered read and write mode
• Hardware-initiated message display.
When the 3480 is operating in compatibility mode, the following 3480
features are not supported:
• High-speed search (block locate)
• Program-initiated message display (MSGDISP macro)
• Dynamic device reconfiguration (DDR)
• Processor assignment
• User-requested synchronization
• Automatic cartridge loader in System mode.
For more information on the functions of the 3480 in full function or
compatibility mode, see IBM 3480 Magnetic Tape Subsystem Introduction
and IBM 3480 Magnetic Tape Subsystem Planning and Migration Guide.
2 IBM 3480 Magnetic Tape Subsystem User's Reference

Conventions Used
The following list of symbols are used to define the format of the macros
used for
the 3480, but you should never type the symbols in the actual
macro statement.
• Braces ({ }) indicate a required field or parameter. When a group of
items appears within braces, you must choose one of the items.
• Brackets ([ ]) indicate an optional field or parameter.
• Items separated by a vertical bar (I) represent alternative items. Unless
otherwise stated, no more than one of the alternative items can be
selected.
• An ellipsis (...) indicates that multiple entries of the type immediately
preceding
the ellipsis are allowed.
• Other punctuation (parentheses, commas, slashes, spaces, and so forth)
must be
entered as shown.
• Boldface type indicates the exact characters to be entered. Such items
must be
entered exactly as shown.
• Italic type indicates fields to be supplied by you.
• Underscored type indicates a default option. If the parameter is
omitted,
the default is assumed.
Chapter 1. The IBM 3480 Magnetic Tape Subsystem 3

Chapter 2. Tape Characteristics
The 3480 subsystem uses compact cartridges containing i/2-inch (l2.65-mm)
chromium dioxide tape. The cartridge is about 25% the size of a standard 2400-foot
(731-meter) reel of magnetic tape, but it stores up to 20% more data than the reel.
Only a single density is available for tape cartridges and is used by the system for
reading and writing.
Changed Format for the IBM Standard Data-Set Label 2
(HDR2/EOF2/EOV2)
The following fields contain changed data for the IBM standard file label 2:
Field 6, Tape Density (1 byte)
• Contents: A code indicates the recording density of the tape. The code is
equivalent to the DEN parameter value on the data definition (DD) statement.
Use code = 0 for the 3480.
• Processing: The field
is neither used nor verified. When data management
creates labels, the information for this field
is obtained from the JFCB.
Field 13, Reserved (8 bytes)
• Contents: For 2400 and 3410 tape drives (for MVSj370 only), the entire field is
reserved for possible future use. For 3420 drives, bytes 40 through 42 are
reserved, byte
43 contains the model number, and bytes 44 through 47 contain
the last four digits of the serial number of the creating tape unit. For the 3480
subsystem, bytes 40 through 42 are reserved, bytes 43 through 46 contain the last
four digits of the serial number of the control unit, and byte 47 contains the
device address (for MVSj370)
or the device number (for MVSjXA).
The serial numbers in the header and trailer labels may
not be the same if the
data set
is opened for update or if DDR is used to swap tape units while the
data set is being created.
• Processing: A unique number identifying the recording unit is read from the
tape during open processing, converted into hexadecimal, and inserted into the
UCBCTD field in the UCB tape extension.
~
Chapter 2. Tape Characteristics ?
2-1