Singer 40 User manual

REFERENCE MANUAL
MODELS 40 AND 42 DISC DRIVES
Copyright © 1972, The Singer Company
All rights reserved throughout the world.
Publication No. 40-298
January 1972
Re-order No. INT 10-211
R1
SINGER
BUSINESS MACHINES

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Models 40 and 42 Reference Manual i

CONTENTS
Page
INTRODUCTION · · · · · 0-1
1 GENERAL DESCRIPTION
· · · · · · · · ·
1-1
2
OPERATOR CONTROL PANEL
· · ·
2-1
3 INSTRUCTION
FORMAT.
3-1
Read and Write Instructions
· · · · · .
3-1
Six-Character Disc Address
· · · · · ·
3-1
4
WroTE OPERATIONS . . · · · · · 4-1
5 READ OPERATIONS . . . · · · · · · · · · 5-1
6
MULTI-PARTITION CONSIDERATIONS .
6-1
7 TIMING CONSIDERATIONS • · · 7-1
8
OPERATING INSTRUCTIONS · · · . · ·
8-1
9 CONDITION CODE SUMMARY · · · · · · · . . · · . 9-1
ILLUSTRA TIONS
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Figure 1-1.
Figure 2-1.
Figure 3-1.
Figure 7-1.
Figure 8-1.
Figure 8-2.
Figure 8-3.
Model 40 Disc Drive .
Operator Control Panel .
Six-Character Disc Address
Disc Sector Layout . • • • . • . • •
Top View of a Model 41B Disc Pack in Its Carrying Case .
Top View of a Model 41A Disc Pack in Its Carrying Case.
Bottom View of a Model 41, 41A, or 41B Disc Pack in
Its Carrying Case .
1-1
2-1
3-2
7-2
8-1
8-2
8-3
Models 40 and 42 Reference Manual iii

Contents
TABLES
Table 1-1.
Table 2-1.
Table 7-1.
Table 7-2.
Table 9-1.
Specifications .
Operator Control Panel.
Timings.
Overlap Timings .
Condition Code Summary .
iv Models 40 to 42 Reference Manual
1-3
2-2
7-1
7-3
9-1
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INTRODUCTION
This manual is intended for those who are interested in the operating and pro-
gramming characteristics of the Models 40 and 42 Disc Drives. Included in
the manual are a general description of the Models 40 and 42; a table of speci-
fications; a description of the operator control panel; a thorough discussion of
read and write operations; discussions of multi-partition and timing consider-
ations; instructions on how to mount and remove disc packs; plus a summary
of all Condition Codes associated with the Models 40 and 42.
Detailed operating instructions may be found in the Model 40 Disc Drive
Operator Instructions, Publication No. 40-023, and the Model 42 Disc Drive
Operator Instructions, Publication No. 40-332.
Models 40 and 42 Reference Manual 0-1

1 GENERAL DESCRIPTION
The Models 40 and 42 Disc Drives are high speed, random access storage
devices designed as peripheral units for the System Ten* computer. Up to ten
disc drives may be attached to the central processor through the File Access
Channel (F AC). A Disc Controller, consisting of printed circuit cards con-
tained in the central processor, acts as intermediary between the disc drives
and the FAC. A particular installation may include both models in any combi-
nation. In external appearance, the two models are identical (see Figure 1-1);
what differentiates them is the type of disc pack used. Both models use
removable disc packs.
The Model 40 uses a disc pack consisting of six magnetic oxide coated discs
joined to one another on a common vertical axis. The discs are approximately
14 inches in diameter and there is approximately .4 inches between successive
discs. The disc pack (Model 41 Disc Pack) has ten recording surfaces. The
top surface of the top disc and the bottom surface of the bottom disc are not
used for recording data.
Figure 1-1. Model 40 Disc Drive
*A trademark of The Singer Company
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Models 40 and 42 Reference Manual 1-1

General Description
The Model 42 uses a pair of disc packs, one mounted on top of the other. Both
packs must be mounted for the disc drive to be operable. The bottom pack
(Model 41A Disc Pack) is referred to as the resident pack and the top pack
(Model 41B Disc Pack) is referred to as the removable pack. Regardless of the
terminology, both packs can be removed from the disc drive by the operator.
When both packs are mounted, they rotate together as though they were one pack.
It is anticipated that the resident pack will remain mounted for extended periods
of time with the removable pack being changed from run to run, day to day, etc.,
as dictated by the requirements of each installation. The resident pack and the
removable pack each consist of three magnetic oxide coated discs joined to one
another on a common vertical axis. The discs are approximately 14 inches in
diameter and there is approximately 0.4 inch between successive discs. Each
pack has four recording surfaces. The top surface of the top disc of each pack
and the bottom surface of the bottom disc of each pack are not used for record-
ing data.
On all three disc packs (Models 41, 41A, and 41B) each recording surface con-
tains 200 concentric tracks and each track is divided into 50 equal parts called
sectors. Each sector contains 100 characters. A write or read operation
always writes on or reads from a single sector.
The Model 41 Disc Pack has a maximum data storage capacity of 10 million
characters. The Models 41A and 41B Disc Packs each have a maximum data
storage capacity of 4 million characters.
The read/write head mechanism of the Model 40 Disc Drive has five arms, one
for each interdisc gap. Each arm has 'two heads: one for the surface above the
arm and the other for the surface below the arm. All five arms move together.
The read/write head mechanism of the Model 42 Disc Drive has four arms. The
mechanism is identical in appearance to the read/write head mechanism of the
Model 40 Disc Drive except that the middle of the five arms is missing.
Like all peripheral devices for the System Ten computer, the disc drives are
independently powered and are turned on and off from their own operator control
panels. Once a pack (or a pair of packs in the case of the Model 42) is mounted
and the power is on, the operator starts the pack rotating by moving the START /
STOP switch on the operator control panel to the START position. When the pack
is rotating at an acceptable operational speed (2400 rpm ± 2%), the READY indi-
cator light on the operator control panel turns on. With the power on, the disc
dri ve is in either of two states, called local and on-line.
When in local, the disc drive is disconnected from the central processor.
When on-line, the disc drive can perform read and write operations in response
to Read and Write instructions executed in the central processor.
The ENAB LE/DISAB LE switch on the operator control panel serves as a com-
bined ON LINE and LOCAL switch. When the' ENABLE/DISABLE switch is in
the DISABLE position, the disc drive is in local. When the READY light is on
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1-2 Models 40 and 42 Reference Manual

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General Description
and the ENABLE/DISABLE switch is in the ENABLE position, the disc drive is
on-line.
The Models 40 and 42 Disc Drives operate within the specifications shown in
Table 1-1.
Table 1-1. Specifications
Dimensions
Width Depth
Height
Inches
30-1/4
24 38
Centimeters
77
61 97
Minimum Service Clearances
Front
Rear
Right Left
Inches
36
36 0 0
Centimeters
91 91 0 0
Approximate Weight
Floor 321 lbs (without 10 lb disc pack)
146 kg (without 4.5 kg disc pack)
Maximum Heat Output/Hour
Electrical Requirements
Voltage Range
Frequency
Current
Maximum Current Surge
Phases
KVA
Operating Environment
Temperature
Relative Humidity
Non-Operating (Storage)
Environment
Temperature
Relati ve Humidity
3,9000 BTU
110-130V ± 10%
60 ± 1
Hz
9.6A
45A for 5 to 10 secs
single
1.1
982.8 kcal
208-230V ± 10%
50 ± 1 Hz
5.0A
25A for 5 to 10 secs
single
1.1
65 to 85°F 18 to 29.5
0C
20
to 75%
-30 to + 150°F
-34 to +660C
8 to 80%
Models 40 and 42 Reference Manual 1-3

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2 OPERATOR CONTROL PANEL
The operator control panels of the Models 40 and 42 Disc Drives (Figure 2-1)
comprise three toggle switches and three indicator lights. The function of each
switch and light is discussed in Table 2-1.
Figure 2-1. Operator Control Panel
Models 40 and 42 Reference Manual 2-1