IBM 3340, 3344 Reference Manual

GA26-1619-4

File No. S370-07

Systems

Reference

Manual for

IBM 3340/3344

Disk Storage

ht

PREFACE

This publication is intended to familiarize

essing personnel with the characteristics

data proc-

of IBM

3340/3344 Disk Storage. The reader should have

prior knowledge of direct-access storage

concepts.

This publication is organized

•

INTRODUCTION

lists highlights and functions.

•

CONFIGURATIONS

by topics as follows:

—

Describes basic units

and ATTACHMENTS

Defines some possible combinations and

attachments for the

•

FEATURES

optional features available

illustrations of some combinations.

•

FORMATS

—

—

and track formats for data.

Record/Track

for capacity calculations of various

• INPUT/OUTPUT

methods,

privacy means.

access times, and identifies

3340/3344.

Describes

Describes and illustrates

both standard and

for the 3340/3344 with

Also provided are

capacity

Lists and summarizes the

charts including

—

Includes addressing

3340/3344 command set and sense

Also includes an

associated error recovery

• OPERATING

switches and indicators

error condition table

actions.

INSTRUCTIONS

associated with the

devices and

system

the

formulas

length records.

security and

byte formats.

and the

—

Describes all

and

record

—

3340/3344 Operator

suggested

instructions for data module

and loading procedures

Read Only Function.

The following

detailed

in this manual:

•

IBM System/370 Principles

No. GA22-7000.

• IBM

Order No.

•

IBM 3340 Disk

Users

•

IBM Reference Manual

Control, Order

•

IBM

Storage

•

The Data Processing

1699,

devices.

• The functional

the parent system. Order

characteristics

System

Order No. GA22-6822.

publications are recommended

information

concerning the

3348 Data Module

GA26-1625.

Storage Fixed

Guide, Order No. GA26-1632.

No. GA26-1620.

Reference Manual

Control, Order No.

defines

terms related to

characteristics

manuals

60 and System/370

13

and Power

and

Panels. Provides

the Enable/Disable

subjects covered

Operation,

of

Handling

Head Feature

Integrated

for

3830 Model

for

GA26-1617.

Glossary,

Order No.

direct-access

manual

numbers for

can be found in

Bibliography,

unloading

for

Order

Procedures,

Storage

2

GC20-

storage

applicable to

functional

the IBM

Fifth

Edition

This

publication replaces

Storage, Order

Significant

are continually

operation of IBM

Copies of this

Offices.

A form for

form

has

This manual was

Publishing,

© Copyright International

ii IBM

(July

1975)

No.

GA26-1619-3,

changes

reader's

been removed,

Department

3340/44

or additions

being

made.

equipment,

and

other IBM publications

comments

prepared

Reference Manual

and makes

Before using

send your

by

G26,

Business

Reference Manual

obsolete.

to the

contact the local IBM

is provided

comments

the IBM

San

Jose, California

Machines

specifications

this

can

at the back

General Products

IBM

for

contained in this

publication in connection

Branch

be obtained

of this

to the address

Division,

95193.

Corporation

3340

Office for

through IBM Branch

publication. If the

below.

Graphics and

1973,

1974,

Disk

publication

with the

revisions.

1975.

CONTENTS

Introduction

IBM

3340 Disk

Storage

Data Module

Defect Skipping

3344-B2/B2F Disk Storage

IBM

3340/3344 Units

IBM

3340/3344

Storage

Special Features

String

Rotational

Fixed Heads

Configurations 4

3340 Storage Without

Model 115
Model 125 (125

Storage Control and Features

Control

Switch

Devices 3

Position Sensing

3344

DDA) 4

(115

DDA)

Model 135 (IFA)

Models 135, 145,

and 168 (3830-2)

168 (ISC)

and

3340/3344

Configurations

155-11,

Models

165-11,

158,

145, 158,

Model 135 (IFA)

Models 135, 145,

and 168
and

3348 Data

IBM

Data

Data

Data

Formats

Record

(3830-2)

168 (ISC)

Module
Module

Surface

Format

155-H,

Models

Module

Types

Initialization

Format 6

165-11.

158,

145, 158,

Count Area

Area

Key

Area

Data

Track Format

Home Address

Descriptor

Track

Records

Data

Capacity

Track

Input/Output Operations

Device

Selection

Device

Address

Seek Address

Access and

Data Transfer Speed

Record (RO)

and Addressing

16
16

16

16
16

Access Motion Time

Head Selection Time

Rotational Delay 17

Transfer

Data

Data Security and Privacy

Read

Only Function 17

Protection

3

3
3

3

3

4

4

4

4
4
4

4

6

6
6

8
8

8

8

8

8

8
8

8

9

File

Verification

Seek

Error Recovery Procedure

Error Correction Function 18

Error Condition Table

Error Recovery Action

Construction of

Channel Commands

Commands

Sense

Control Commands

Restart

CCWs 18

Read Commands

Write Commands

Search Commands

Sense Data

4,

1,

Summary

0-7

Summary

and

5

Message Summary

Sense Byte

Sense Bytes

Formats

3340

Sense Byte Format 1 Summary

3344 Sense Byte Format 1 Summary 39

Sense Byte Format 4 Summary
Sense Byte Format
Sense Byte Format 6 Summary

Operating Instructions

3340 Operator

Panel

Summary

5

3344 Operator Panel

3340/3344

Power Panel 45

Machines Without String Switch Feature
Machines With String Switch Feature

Module Loading

Data

Module Unloading

Data

Read Only Function 47

Enable Read Only Function

Disable Read Only Function

Index

16

16

17

17

17

]

18

18

18

25

25

25
25

25

25

34
34
35

36

37

41

42

43

44

44
44

45
45

46

46

47

47

48

7

Contents iii

FIGURES

Figure 1.
Figure
Figure
Figure
Figure

Figure 6. Record and Track
Figure

Figure

Figure
Figure

Figure
Figure

IBM

3340/3344 Disk Storage

IFA

2.

3. ISC

4. Data Surface Track

5. Data

7.

8.

9.

10. Data

11. Error Condition Table

12.

3340/3344

3830-2

or

Module

Geometry

Track/Cylinder

Data Module

Capacities

Track/Cylinder

Module

Recovery

Action

Maximum Configuration

Capacities

Maximum

Configuration

Layout 7

Format

Capacities

Capacities

Table

-

No

-

Keys

No

-

With

-

With Keys

Keys

Keys

.

.

10

12

.

.

.... 13

14

. . 15

20

21

Sense

2

5
5

7

Commands

Control

Read

Write

Search

Sense

Formats

3340

3344

Format
Format

Format

Operator Panel,

Power

Data

Read Only

Commands

Commands

Commands

Commands

0-7

Bytes

and 5 Message

1, 4,

Sense Byte 1 Summary

Sense

Byte 1 Summary

4 Summary

5 Summary

Summary

6

Panel,

3340/3344

Module

Load/Unload

Function

Summary

3340 and

Summary

3344

26

27

29

31

33

35
36

37
39

41

42

43

44

45

46

47

iv IBM

3340/44 Reference

Manual

INTRODUCTION

The IBM 3340 Disk

access storage for IBM System/370

135, 145,

consists
storage,

155-11,

of a Model

and up to three attached

(Bl) drive units. The 3344

unit can be

substituted

on IBM System/370

Storage provides direct-

158, 165-11,

and

A2, control with dual-drive

large-capacity,

for the 3340

Models

135, 145,

165-II,and 168.

The

3340/3344 is

capacity

communication, or

disk storage

modular,

a

high-speed,

subsystem for data

general purpose

IBM 3340 DISK STORAGE

The IBM 3340 direct-access

technological

skipping.

advances: a data module and

Data Module

The sealed

disks, drive spindle,

arms. The data module

disk pack:

•

The drive

using a different

•

The heads, storage disks,

sealed inside

ination from

tive

• Reliability

data that it

Defect

Defect skipping

and following

track can

the heads no

track,

Data module capacity is not

ping and

data module cartridge

read and write

data storage capacity can

data module.

the data

outside sources

maintenance.

is improved as each

previously wrote.

Skipping

allows data

surface

a

be used except

longer need

access time is saved.

the user

is unaware of

storage

contains

has several advantages

and drive

module.

This avoids contam-

and reduces

head reads

to be stored both

defect.

for minute

All of the recording

be moved to an alternate

changed

defects.

Models

168.

dual (B2)

115,

The 3340

or single

dual-drive

B-type units

155-11,

large-

base, data

use.

introduces two

storage

heads, and access

158,

defect

over

be changed

spindle are

preven-

only the

ahead of

portions. Since

by defect

skip-

125,

disk

a

by

IBM

3344-B2/B2F

The IBM

increased

storage. Each

quantity

using

the 3340

370 Models

The

Defect skipping,

is also

IBM

The

of four

3344-B2/B2F

capacity,

of data of

fixed

media. The 3344

B-drives

135, 145,

3344-B2F contains

used

by the 3344-B2/B2F.

3340/3344 UNITS

3340/3344 disk storage is

dual-drives. The

3340 Model A2

and their

attached

The

mechanisms.

the

contains

circuits

sequencing

The

module

The

instead

tics apply

control logic.

dual-drives

3340 Model

The

Model B2 contains

all necessary

for internal

comes from

3340 Models

as a storage medium.

3344 dual-drive

of a data module.

to both

DISK

lower-cost-per-byte,

3344

a 70-megabyte

in a 3340

similiar

containing

are controlled

B contains

Model Bl contains

use,

A2, B2, and Bl use

models

storage

3344 storage capacity

and start time is not

not moved.

The

3340/3344 offers

• Start

• Average

•

• Nominal read/write

• Data module

Average

second

bytes

time

access

rotational

significant because

-

less

than 20 seconds

time

capacity

STORAGE

dual-drive

drive

stores four

155-11,

fixed head

to that used on the

input/output

two independent

Up to three additional

either one or two

two

drives. Each

electronic and power

but data control and

the A2 unit.

use fixed

The following

device types except

is 279.5 million

the following:

-

25 milliseconds

-

delay

-

rate

-

34,944,768

unit provides

times the

data module

dual drives

string on IBM

165-11,

158,

storage.

made

up

interface

by the A2 unit.

single

a

the 3348

media storage

bytes-per-drive

the storage is

10.12

milliseconds

885,000

bytes-per

or

direct access

can replace

System/

and 168.

3340,

of

a maximum

is a

drives

drive

drive;

model

supply

power

data

characteris-

that the

69,889,536

by

Introduction

1

3340-A2

3340-B1

3340-A2 (Control

IBM

CONTROL

•

Interprets

storage

•

Regulates

interfaces

•

Serializes and

•

Checks data

correction

• Furnishes status

•

Performs

storage

DRIVES

•

Responds

(controller)

•

Houses,

which has

70F)

•

Positions access

maintains

system

• Selects the head

•

Reads

•

Provides safety

tem and

and executes

control

the storage

integrity by

analysis

diagnostic

string

commands from

to

loads, filters, and

various capacities

track following

or writes data

system

and Two

macro-orders

control and disk

deserializes data

error detection

system

to the

evaluation of

drives a 3348

mechanism

with electronic

servicing

and

evaluation

Drives)

the

from

storage

error

and

the 3340/3344

3340-A2

the

module

data

(Models 35, 70,

with voice-coil

information for subsys-

and

and

servo

3340-B1

IBM

Drives), and IBM 3344 (Two Drives)

•

Responds

(controller)

• Positions

maintains

to commands

access

track following with

Drive), IBM 3340 B2

(One

from the 3340-A2

mechanism with voice-coil

electronic servo

system

• Selects head

•

Reads and

•

Provides safety

tem

3340-B1

the

drives

capacities (Models

3344-B2 and 3344-B2F: Houses,

two fixed

capacity

volumes, a total of 279.5

writes

data

and servicing

information

and system evaluation

and 3340-B2:

Houses, loads, filters, and

3348 data module(s) of various

35, 70,

media drives.

and 70F).

filters, and powers

3344 drive is equivalent

Each

and format to four logical 3348 Model 70

million bytes of data.

(Two

and

for subsys-

storage

in

Figure 1.

IBM 3340/3344

2 IBM 3340/44

Disk Storage

Reference

Manual

3340/3344 STORAGE

CONTROL AND

FEATURES

STORAGE CONTROL DEVICES

The following storage

date 3340/3344 disk storage.

•

3830 Model 2 Storage Control.

• System/370

Storage

•

System/370 Model 145 ISC.

• System/370

Models

3345

•

System/370 Model 135 Integrated

ment

(IFA).

SPECIAL

The 3340

Model

the remote

with Rotational

Storage.

The

Rotational Position Sensing is standard.

Storage is

The

the Model B2

String

The string switch feature is installed

(controller). This

be dynamically shared by two storage

The feature includes

switches allowing

storage control

control switch permitting the switches

from a 158 or 168

A2

3344 disk storage has no

3344

Switch

Models

Control (ISC).

Model 145 Storage Control Frame

FEATURES

disk storage has four

can be supplied with the

switch. All 3340 models

Position Sensing

available,

Model B2F contains fixed

does not.

or accessible by

control

158

and 168 Integrated

and 5.

3, 4,

special features. The

special features, as

but must be ordered

feature permits

interlocked

two

the string to be

each. A remote

Multiprocessor is

devices can accommo-

string switch and

can be ordered

and Fixed Head

head storage and

on the 3340-A2

the 3340 string

Enable/Disable

dedicated to either

also available.

File Attach-

Fixed Head

model.

by

to

control devices.

to be activated

Rotational

The rotational

the channel

given record after

selected.

on the

and permits

during the time required for

required record

Additional

mands are found

•

Reference Manual

Control, Order No.

• Reference Manual

Order

Fixed

The

3340 fixed

3348-70F data module

70-megabyte

addition

heads,

have zero

data

module storage,

storage under

The 3344-B2F

head

1.004

fixed

addresses

For further

usefulness

IBM

sales

Feature

Position

position sensing

connection time required

the track and

This

feature (optional on the

3344) disconnects

other channel operations

to the read/

details on RPS and its

in the following

No.

GA26-1617.

Heads

head feature

data

module contains

to the normal

500 thousand

seek

the moving heads

storage.

million

head storage is

each 3344

on

details on

to your storage

representative

Users Guide, Order

bytes of storage

time. The feature does

because an

dual-drive

In this model, both

bytes of zero seek time

associated only

the fixed head feature

Sensing

for

GA26-1620.

for

on any

access heads.

drive

or see the Fixed

(RPS) feature

to

head have been

the drive from

to

the spindle

write head.

associated

publications:

Integrated

3830-2

permits use of the

Storage

3340 drive. This

fixed heads in

With these

are available

equivalent amount

becomes

also

is

equipped

3344 drives

(see

Figures

application,

No. GA26-1632.

reduces

search for a

3340, standard

the channel

be performed

to bring the

com-

Storage

Control,

fixed

that

not increase

inaccessible.

with fixed

have

storage. This

with the

2

and

primary

and its

contact your

Head

of

3).

3340/3344 Storage

Control and Features 3

CONFIGURATIONS

various

The

divided

are

3340 units,

and

3340

listed by

3340

In some

storage

Model

The

(DDA)

attached:

model,

STORAGE

System/370

devices can

115

Model

for

3340-B2

Model 125

Model 125

The

attach one

can

Model 135

Model 135

The

for

(IFA)

string and

3340

a

3333/3330

configurations

two

into

configurations

and

units. These

3344

follow.

WITHOUT

(115DDA)

115 uses the

storage

3340-A2

a

(dual) orBl

(125DDA)

storage

drives can

control.

uses

string

(IFA)

uses the

control.

a

of 3340/3344

groups:

models, strings

be used

configurations

using a

attachment

addition to the

in

Direct Drive

Four drives

drive with

dual

(single)

the DDA

of up to

string of either

be

drive.

for

eight 3340

Integrated File

Sixteen

attached.

combination of

methods,

3344

of 3330

Attachment

can be

control,

storage

drives.

Attachment

drives,

or

3340

disk storage

only

using

and 3350

3340s.

and a

control and

two strings,

3340/3344

When the

drives

3344 requires

A

the

Only

support

CONFIGURATIONS

3344

can be

attached to

145,

135,

the 3344 dual

Model 135 (IFA)

Model

The

maximum

storage

3340/3344

Models 135, 145,

(3830-2)

Sixty-four

ISC

or

attached.

and a

attached.

Figure

tion.

units.

assigned

135 Integrated

34

of

strings to

string (see

Models 145, 158,

logical addresses

when a

path

Two

string of

short

3 shows the

Only strings

Each drive

relative to

used,

is

logical

four

155-11,

drive.

logical

attached: a

be

Figure

155-H, 158,

3340/3344

strings

of

four 3340

maximum

and

has the

the

neither 3333/3330

the same storage

addresses

158,

File Attachment

addresses.

for

165-11, and 168

allows two

This

3340 string and a

2).

165-11,

and 168

and 168 (ISC)

can be

3340/3344s,

used by a

configuration is

3340 string,

a

drives can be

3340/3344

incorporate the

2 can

hexadecimal

storage control

addresses

as shown.

nor 3350

control.

each drive.

has a

3830-2

configura-

3344

Models 135,

(3830-2)

Storage

3830*2
3836-2

four

combination.

Models 145, 158,

control

an

or

and

strings

155-H,

145,

the

for

Integrated

ISC

each

3333/3330s,

of

models

path

165-11,

158,

and

Storage

can attach

3340s,

(ISC)

168

shown

Control.

or 3350s

168

and

is either a

The

to 32

up

drives,

in

any

4 IBM 3340/44

Reference Manual

3135

IFA

Drive

No.

Drive

No.

String

3340-A2 3344

00

!

String 1

01

1

3340-A2

08

!

*

09 0A

|

1 2

Primary Addresses

02*

10
16

1C

2

3340-B2

03*

11

17

1D

3

OB OC

|

3 4

3344 3344

04* 05*

12
18

13

19

1E 1F

4

5

3340-B2

| OD OE

5 6 7

06*

14

1A

20

6 7

3340-B2

|

07*

15

1B

21

OF

Figure 2. IFA 3340/3344 Maximum Configuration

String

3340-A2

Storage
Control

Driw

i 1

00 01

No.

String

1

3340-A2

Drivi

5 1

No.

08

String 2

09

|

3340-A2

12 13

Drivi

2

i

3

No.

String 3

3340-A2

' in

1

a

18 IC 1A

(Hexidecimal

3344

02*

22

2A

03*
23

2B

addressing)

3344 3344

04* 05* 06* 07*

24

2C

25

2D

32 33 34 35

2

3

3340-B2

0A

| OB OC

2 3

3344

10* 11* 14*

20
28

21

29

4

3340-B2

4

3344

1C

38

5

OD

|

5

15* 16* 17*

1D

39

30 31 3C 3D

1

4

5 6 7

3340-B2

26

2E

36

6 7

3340-B2

OE

|

6 7

3344

1E

3A

3E

27

2F

37

OF

1F

3B
3F

Figure

3. ISC

or

*

Primary

3830-2

3340/3344 Maximum Configuration

Addresses

(Hexidecimal addressing)

Configurations

5

IBM

3348 DATA

MODULE

DATA

The 3340

storage

Model 35

3348

MODULE

models

medium.

with about 35

Model 70

and the 3348

including

The

one-half million bytes

Models 35 and

3340 drives, but the

on 3340 drives

only

the

use.

3348-70

tracks

Model 70F

3348-70F data

The

tics as

accessed by

are

fixed heads

the

The other

subject to normal

The three data modules

tics:

Capacity

Byte

track

Per
Per

cylinder

module

Per

DATA

All 3348 data modules are

tured.

written on each

the

ment bytes.

control uses the skip

defective area.

tive during

available to flag

if

for DOS).

MODULE

Home

written home

normal use, IBM

required

(DASDR and ATLAS for OS

During

TYPES

use the IBM 3348 Data

Three types are

with about 70 million bytes of storage,

Model

70F with about 70

can be freely

70

Model

that have

module has

except

the fixed

available

is

(cylinders and 6 through

access delays.

head

have the

34,944,768

INITIALIZATION

address and 8-byte

track. If a

address contains

normal operations the

displacement

If a module data area

defective tracks

Module as a

available: the 3348

million bytes

of storage, the

million bytes

under fixed heads.

exchanged on

70F can use its

been converted for

the same characteris-

that cylinders 1

heads. Data on tracks

with only

following

3348-35

8,368

100,416

initialized

descriptors (R0) are

skippable defect

the skip

bytes to bypass

utility programs are

and assign

through

rotational delay.

characteris-

3348-70,-70F

when

storage

becomes defec-

and

the

fixed heads

5

under

are

695)

8,368

100,416

69,889,536

manufac-

is found,

displace-

the

alternates

DASDI

DATA

SURFACE

The disk data

of data called

two magnetic read/

uses

tracks and one

surface of the disk

bered tracks are on one side of the

even numbered

point starts the

the even.

they

inside,

the

In

outside heads

When the

service four

and one

3348-35

form a cylinder. All odd

side of

side.

The

track geometry is the same as that of the smaller

the three disks

3348-70

data module contains four disks. The

FORMAT

surface is

tracks (see

for the

tracks are on the

odd tracks and

outside.

data module the

and those

divided into concentric bands

Figure

write heads, one for the inside

outside tracks. The recording

is divided in half.

heads are at

tracks: one

under the three inside heads

numbered tracks are on one

and the even tracks on the other

Each data surface

4).

All

dividing line and all

other. The odd index

the even index starts

given position,

a

odd, one

tracks under the three

odd

even,

num-

one

data

module with a cylinder available at each position. Odd

numbered cylinders are on the upper three surfaces

and the

single

position

cylinders can

cylinders are on the lower three. From a

even

two consecutive (even and

accessed (see Figure

be

5).

odd)

The differences between the storage media used on the

3340

data storage

units follow:

3348-35 3348-70

Data Surfaces per Module

Physical

Logical

Heads per Surface

Cylinders

Alternate 1

per Module 348

CE

Logical Cylinders

Cylinder 1 2

Physical Tracks

Cylinder 6 12

Logical Tracks per Physical

Cylinder 12 24

Logical Tracks per Logical

Cylinder 12 12

Logical Tracks per

per Physical

per Physical

Physical

2

2 2

696

1

2

2
2

Track 2 2

6 IBM 3340/44

Reference

Manual

Even

«ndex

Point

Megabytes

70

Cylinders

001.003.

005.

(heads

index

Odd

Cylinders

000.002.

004....

(heads

...

6-11)

Point

0-5)

Both

Odd

Cylinders.

follow

odd

tracks

follow

Figure

4. Data

and Even

Odd

tracks

index;

even

even

index.

Odd Cylinders

001,003,

005

(heads 6-11)

Even

000,

004

(heads 0-5)

699,

Cylinders

002,

698.

Surface

Track Layout

3348-35

3348-70

Note:

In

located

on the bottom

the

3348-70F data

*£.

surface

5V

11

module,

cylinders 001-005

of the bottom disk.

7«

10

8r

8*-

wmTQ

are

Data

Heads

Figure

5. Data

Module

Geometry

IBM

3348

Data Module 7

FORMATS

RECORD

The basic

a byte

separated by a special gap

combined to

ation. A

FORMAT

unit of

consisting

make a

record consists

information recorded by

of eight

record, the logical

Count Area

The count

on a

data areas

when

record is

the

Key

Use of the key

mer.

primary

the

record

part

Once

the length) may be
the data area

Data

The data

the

tion is organized

The

area.

(but not the length) may

the data

other area in

area contains the

specific

the record is formatted

track and

of the

reformatted.

defines the size of the

record. The

Area

area is at

used, the key area of

When

identification of the data

(such as social

security

number).

the key

area is

of the

formatted, the contents (but

altered. If

record

Area

area contains the

count and

length

Once

key areas

and arranged by

of the data area is defined by

the data area

area may be altered without

the record.

TRACK FORMAT

All tracks are

point (see

format:

or more

the records,

initially formatted

Figure

6).

Each

home address, track

data records. The records, and

are separated by gaps.

the drive is

bits. A group of bytes

is called

of count,

location

an area.

key, and data areas.

of

Areas are

unit of inform-

record

data

a

key and

count area is written

and is not

the discretion

the record

changed

of the program-

portion of the

until

contains

number, man number,

not

the key area is

also be

must

information

of the record. Data informa-

programmer.

the

is formatted, the contents

be altered.

track

descriptor record, and

The

affecting any

beginning at an index

has the

altered,

rewritten.

identified

the count

contents of

same basic

areas within

by

one

Home Address

Each track

physical location of the track (track address) and

the

condition of the track.

the

contains one home address,

Home address is the first

recorded area following an index

Specific commands

home address area:

are used for

Write Home Address and Read

Home Address. Home address

defective track. Writing home addresses is

the

flag

usually done at

Track

This record

following the home

Descriptor

ming systems, the RO count

provides the

alternate track,

of the defective track. An 8-byte

store the

Specific commands, Write RO

writing and reading the track descriptor

for

the IBM plant.

Record (RO)

is always the first record on the track

address area.

address of the alternate track. If it is an

the RO count area

number of bytes

writing and reading

is normally rewritten

field of the defective track

remaining on the track.

and Read RO, are used

Data Records

or more data records may follow the track

One

on

descriptor record (RO)

determined at

of the record are originally

Format

rewritten by

Data records, as

be formatted

organization determines

the time the count, key,

Write command. The

another Format Write

well as track descriptor records, can

with or without keys.

track. Record format is

a

written by execution of a

format of the record is

whether keys are used.

RECORD OVERFLOW

The record overflow

processing

track.

logical records that exceed the

When using

boundary limits the

function

overflow

size of the record.

provides a means of

records, the

which defines

point.

In IBM program-

proyides the address

data field is used to

and data areas

command.

Generally, file

capacity

cylinder

a

to

record.

of a

8 IBM 3340/44

Reference

Manual

TRACK

The number

track depends

equation can be

length records per

standard RO

consideration.

Equal

where:

The

lengths

the

accounted for):

Records n

Track =

CAPACITY

of records

that can be

on the record size. The

used to

space

length records _ 8,535

track C +

C(overhead/record)=

determine the

track. The home

and skip defect are taken into

KL

167 if

=

242

Key length

KL=

Data length

DL=

number of records (n) of different key and data

that can be

following equation

8,535 >

recorded on a track

(the standard RO is already

KL

C

+

£

recorded

following

number of

address and

(track capacity)

DL (bytes/record)

+

=

KL

if KL

#

must

DL

(») +

G)

i= 1

where:

C
C

=

167ifKL

=

242 if KL

=
/

on a

satisfy

equal

When RO is

be used:

Records =8,706

Track

where:

The tables

mum

sizes of n

n is all

module capacities are given

bytes and the number of

There are tables for records without keys,

records with keys. In all

address and standard record zero (KL

already accounted for.

possible values.

standard, the following formula

not

>

[KL(o)

n

£[KL(i)

=

i

=

C

-

C

shown

in Figures 7 through 10 give maxi-

equal-length records on a track where

DL(o)

+

1

167ifKL

242 if KL

Track, cylinder, and

in both the number

records.

tables,

+ C-4]

DL(i)

+

=
#

overhead for home

=

+ C]

and for

DL

0,

+

data

should

of

=

8)

is

Formats

9

Index

Home

Address

SD

1

PA

/

F

G2

/

/

CC

1

Standard

t

/

H H

1

RO Count

Area

K

R

L D L

...J,,.,

RO does not

/

DCB

Record Zero RO

G2

/

G2 Key t DCB

contain

-Track Format

A

ROKey

Area t

an RO key area

G2

1

DATA DCB

G2

or

associated

RO Data

Area

/

/

/

gap.

System

Data

I

G3<

(System/

'Storage

/

^Control)

(Disk

to

Storage

J

G3

^Control

fData

beginning of each track.

INDEX: Indicates

the disk surface are

G1 (Gap 1):

the

synchronized by

Separates

Index and

HOME ADDRESS

SD (Skip

displacement

PA (Physical Address):

verification.

Note:

ing

transparent to the using

F (Flag):

The

system.

CC

HH (Track Number):

with

DCB (Detection Code Bytes):

and

Figure 6.

Displacement): Storage

condition of track.

Storage

The SD

only the storage

Bit

Bits
Bits 6

flag byte may

(Cylinder Number): Specifies the

3348-35

For

3348-70

For

3348-

For

the selected

3348-35

For

3348-70

For

3348-70F

For

used for error

and PA bytes are

Defines track

-

Displacement

Skip

and 5

,

2,

1

4,

-

and 7

the

It is

70F

Record

control

system.

condition as

-

Unused.

=

Normal Track

00

=

Alternate

01

10=)

11

be

only

cylinder:

Defective Track

=

j

transferred to and from the

flag byte

347

to
to 695

695

to

Specifies

0-11

0-11

0-1

(cylinders

1

detection.

Track Format

and

Index.

Home Address.

control indicators

control

internal

drive. The function is

and

transferrable.

(cylinders

the read/write

Generated by

check for

conventions

follows:

Track

cylinder number:

1-5

1-5

fixed

All tracks on

using

fixed heads)

track number

heads)

3340-A2

the

for

involv-

skip

G2 (Gap

Separates home address and R0 count

2):

RECORD ZERO

COUNT

R0

SD and

F

(Flag): Defines track

records.

Bits

Bits 3 and 5

Bit

Bits 6

(Cylinder Number): Specifies

CC

For
For

For

HH (Track Number): Specifies the read/write

within the selected cylinder.

For
For

For

R (Record Number): Normally

KL (Key

key area,

has a

DL (Data Length):

data area,

normally

DCB (Detection Code Bytes):

and used for error detection.

AREA

PA:

Same as

—

0—2

-

4

When on, indicates that

the

on

and 7

Home Address.

Skip Displacement

—

Unused,

next

-

=

00

=

01

10=

11=/

3348-35
3348-70

3348-70F

3348-35
3348-70

3348-70F

Length):

from"

value of Hex

from

has a value of

to
to
to

0-1

0-1
0-1

Specifies

0—255

00.

Specifies the number of bytes in the

track capacity. For standard

1 to

condition identifier

Indicators.

bit

is always zero.

5

logical record continues

a

track.

Normal Track

Alternate

)

Track

Defective Track

the cylinder

347

695

695 (cylinders

(cylinders

1

the number of bytes in the R0

bytes. For standard

Hex

08.

1-5

1—5

value of Hex

has a

Generated

fixed heads)

fixed heads)

by

area.

for overflow

number:

number

track

00.

R0, this normally

R0

R0, this

the

3340-A2

10 IBM

3340/44

Reference Manual

System Data)

(System/

Storage

Control)

Disk

to

Storage

Controi

Data

Track

G3

^

G3

Format

R1-RnCnt

Area

K

\

\

PA

SD

I

Data

Record R1-Rn

G2

R1-Rn

Area

A

Key

G2

R1-Rn

Area

Data

Index

G4

A

K

F

CC

H H

R

L D L

I

I

I

I

DCB G2

Key

DCB

G2 DATA

DCB

G2 (Gap 2): Precedes

KEY

RO

KEY

standard RO, this

DCB (Detection

bytes are generated

detection.

G2

AREA

AREA: Identifies

area is

Code Bytes): If

(Gap

2):

Precedes

RO DATA AREA

DATA AREA:

count

and key

DCB

(Detection

and used for

DATA

RECORD

G3 (Gap

DATA

DATA

F (Flag):

CC

RECORD

RECORD

(Cylinder Number):

For

3348-35

For

3348-70

For

3348-70F

3):

Same

Contains the

areas.

Code Bytes):

error

detection and

COUNT AREA (R1-Rn)

Precedes

COUNT AREA

as Record

all key areas.

information in

not present

by the

3340-A2 and

all

data areas.

all count

Zero.

Specifies the

to 347
to 695
to

695 (cylinders

on the track.

key

area is written,

information

Generated

correction.

areas,

except RO,

cylinder

1-5

the

data area. For

used for

identified

by the

number:

fixed

heads)

these

error

by the

3340-A2

HH

(Track Number):

within the selected cylinder:

For 3348-35
For 3348-70
For

3348-70F

R

(Record

the

KL

key area,

DL

data

DCB

and used

G2

DATA

KEY

DCB

and used

G2

(Gap

DATA
DATA

the count

record

(Key

Length):

from 0-255

(Data

Length):

area, from

(Detection

for

(Gap

2): Precedes

RECORD

AREA:

(Detection

for

2):

RECORD

AREA:

and

Number):

on the

error

Identifies

error

Precedes

key

Specifies

0-11
0-11
0-11

track

Specifies

Specifies

1

to track

Code

detection.

KEY

Code

Bytes):

detection.

all

DATA

Contains

areas.

(cylinders

Specifies

if

bytes.

Bytes):

all

AREA

information

data areas.

AREA

the

the read/write

the

specified

the number

the

capacity.

Generated

key areas.

(R1-Rn)

Generated

(Rl-Rn)

information

1-5

sequential

by

programmer.

number

in

the

fixed

heads)

of bytes

of bytes in

by the

data

by

the

identified

track number

number

of

in the

the

3340-A2

area.

3340-A2

by

DCB

(Detection

and used for

G4 (Gap

Index.

defect.

4): Padding

If

Code

error detection

used for

defect

Bytes):

from

skipping,

Generated

and

end

of the

correction.

last

G4 is

centered

by the

data

3340-A2

area

to

over the

Formats

1

Record Length

(DL)

(Bytes)

8,368
4,100

2,678

1,966

1,540

1.255 6
1,052

899

781 9 7,029

686

608

Track

(Records) (Bytes) (Records)

1

2
3

4

5 7,700

7 7,364

8 7,192

10

11

544 12 6,528

489 13

442 14

402

15

366 16

335

17

307 18 5,526

282

19 5,358

259 20

239

21 5,019

220 22
204 23 4,692

188 24
174 25 4,350

161

149 27
137
127 29

117 30 3,510

26

28

108 31

99

91

84

76

32 3,168

33 3,003

34
35 2,660

70 36
63 37 2,331

57

51 39

46

41

36

•31

26
22

18
14 47 658

10

7 49
3

38

40 1,840

41 1,681 492

42 1,512
43 1,333

44
45 990

46

48

50

Capacity

8,368
8,200

8,034

7,864

7,530

6,860
6,688

6,357

6,188
6,030

5,856

5,695

5,180

4,840

4,512

4,186

4,023

3,836
3,683

3,348

2,856

2,520

2,166

1,989

Cylinder

12

Capacity

(Bytes)

100,416

24 98,400

36

96,408

48 94,368

60

92,400

72 90,360

84

88,368

96 86,304

108

120
132

144 78,336
156

168

180

192

84,348

82,320
80,256

76,284
74,256
72,360
70,272

204 68,340

216
228

66,312

64,296

240 62,160
252
264

276

60,228

58,080

56,304

288 54,144

300 52,200

312
324

336

50,232

48,276

46,032

348 44,196
360

42,120

372 40,176

384 38,016
396

408
420

36,036

34,272

31,920

432 30,240
444 27,972

456 25,992

468

23,868

480 22,080

20,172

18,144

15,996
13,728

11,880

9,936

1,144

828 552

504

516
528

540

564 7,896

480 576

5,760

343 .588 4,116

150

600 1,800

Record

IBM 3340/44

12

Figure 7.

Reference Manual

Capacities

per Track

and Cylinder

-

Without Keys

Records

MODEL

35

Bytes

MODEL

Records

70/70F

Bytes

4,176

8,352

12,528
16,704

20,880

25,056

29,232

33,408

37,584

41,760
45,936

50,112
54,288

58,464

62,640

66,816
70,992
75,168

79,344

83,520

87,696
91,872 20,21

96,048

100,224

104,400

108,576
112,752
116,928
121,104
125,280

129,456

133.632
137,808

141,984

146,160

150,336

154,512
158,688

162,864

167,040
171,216

1

75,392

1

79,568

183,744

187,920
192,096

196,272

200,448

204,624

34,944,768

34,243,200
33,549,984
32,840,064

32,155,200
31,445,280

30,752,064

30,033,792

29,353,104
28,647,360
27,929,088

27,260,928

26,546,832

25,841 ,088

25,181,280
24,454,656 133,632
23,782,320

23,076,576 1

22,375,008

21,631,680

20,959,344

,840

1

19,593,792

18,842,112

18,165,600

17,480,736 217,152

16,800,048

16,019,136

15,380,208

14,657,760
13,981,248
13,229,568 267,264

1

2,540,528 275,616

11,926,656
11,108,160
10,523,520 300,672

9,734,256 309,024 19,468,512

9,045,216 317,376
8,306,064 325,728
7,683,840 334,080
7,019,856 342,432
6,314,112
5,566,608 359,136 11,133,216

4,777,344 367,488

4,134,240

3,457,728
2,747,808 392,544 5,495,616

2,004,480 400,896 4,008,960

1,432,368 409,248

208,800 626,400

Figure

8. Record

Capacities per

8,352

16,704

25,056

33,408

41,760

50,112

58,464

66,816
75,168
83,520

91,872

100,224

108,576
116,928
125,280

141,984

50,336

158,688
167,040
175,392

183,744

192,096

200,448

208,800

225,504

233,856
242,208
250,560
258,912

283,968 23,853,312

292,320

350,784

375,840 8,268,480

384,192

417,600

Data Module

-

Without

69,889,536

68,486,400

67,099,968

65,680,128

64,310,400

62,890,560
61,504,128

60,067,584

58,706,208

57,294,720
55,858,176
54,521,856

53,093,664

51,682,176
50,362,560

48,909,312
47,564,640
46,153,152

44,750,016

43,263,360
41,918,688
40,423,680

39,187,584

37,684,224

36,331,200
34,961,472

33,600,096

32,038,272
30,760,416
29,315,520
27,962,496
26,459,136
25,081,056

22,216,320
21,047,040

18,090,432

16,612,128

1

5,367,680

14,039,712
12,628,224

9,554,688

6,915,456

2,864,736

1,252,800

Keys

Formats

13

Record

Length Track Capacity

(KL+DL)

(Bytes)

8,293

4,025

2,603

1,891

1,465
1,180

977

824
706

611

533

469 12

414

367 14
327

291

260

232

207

184 20
164
145

129
113

99
86

74

62
52

42

33

24

16

9

Cylinder

(Records)

1

2

3

4
5

6

7

8

9

10

11

13

15

16

17
18

19

21

22
23

24

25
26

27

28
29

30

31

(Bytes) (Records)

8,293 12 99,516

8,050
7,809

7,564 48 90,768

7,325

7,080
6,839

6,592

6,354

6,110

5,863

5,628

5,382
5,138

4,905
4,656

4,420

4,176

3,933

3,680

3,444
3,190

2,967

2,712

2,475 300

2,236

1,998
1,736
1,508
1,260

1,023

24

36 93,708

60 87,900

72 84,960
84 82,068
96 79,104

108

120
132

144 67,536
156 64,584

168
180

192 55,872

204
216 50,112
228
240 44,160

252 41,328

264 38,280
276 35,604

288 32,544

312 26,832
324 23,976

336 20,832
348 18,096
360

372

32 768 384 9,216
33

34

528

306

396 6,336

408 3,672

Capacity

(Bytes)

96,600

76,248

73,320
70,356

61,656

58,860

53,040

47,196

29,700

15,120

12,276

Record

9.

Figure

IBM 3340/44

14

Reference

Manual

Capacities

Track and Cylinder

per

-

With Keys