Digilog Electronics MSU IV User manual

;·OPERATOR'S
INSTRUCTION MANUAL
MS U IV· ,·~;::-;:~::;
MASS STORA~GE'
·U NIT ... '.ttt~)·.'>.

OPERATOR'S MANUAL
MSU IV
MASS STORAGE UNIT
DIGILOG, INC.
NETWORK CONTROL DIVISION
1370 WELSH ROAD
MONTGOMERYVILLE, PA 18936
[phone]
TWX 510-661-0060
This document contains information that is proprietary to
DIGILOG, Inc. Reproduction or distribution without prior
written approval is prohibited. All rights reserved.
This publication is subject to change without notice.
First Edition: August, 1982
PIN 98-7004-00 Rev A

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.. ·~ "."'" ,,
·'•...L '·'.
MSU IV OPERATOR'S MANUAL
PREFACE TO FIRST EDITION
'~, :·.t edition of MSU IV' s Operator's Manual provides the information
to ooerate DIGILOG's MSU IV mass storage unit. It is intended to be
the manual supplied with a DIGILOG DLM data line monitor, as well as
~anuals that are supplied with other communication system equipment •
.a er 1 of this manual contains a general description of MSU IV along
··'~· ~ listing of its characteristics and specifications.
Chapter 2 contains descriptions of the unit's controls, switches, indi-
cators, and connectors.
Chapter 3 provides the information necessary to connect and operate the
unit in conjunction with a DLM, or a standalone RS-232 communication line.
Every attempt has been made to include the latest and most accurate infor-
mation in this manual's first edition. Users are requested to submit any sug-
gestions or corrections that they believe should be included in the manual's
next edition. Suggestions for changes should be directed to:
Manager of Documentation
DIG I LOG, Inc.
1370 Welsh Road
Montgomeryville, PA 18936

MSU IV OPERATOR'S MANUAL
TABLE OF CONTENTS
CHAPTER
DESCRIPTION OF EQUIPMENT
Paragraph
1•1
1. 2
1.3
2. 1
2.2
2.3
Introduction
General Description
Specifications and Characteristics
CHAPTER 2
CONTROLS, INDICATORS, AND CONNECTORS
Introduction
Operating Voltage Selection and
Applying Power Fuse Replacement
2.4 Front Panel Disk Drives, Control
2.4.1 Disk Drive Units
Keys, and Indicators
2.4.2
2.4.3
2.5
Control Keys
RUN and HALT Keys
DISK INITL Key
DRIVE SEL Key
READ WRITE Key
STOP/CONT Key
EVENT MARK Key
OPER SEL Key
TRACK FWD Key
TRACK BACK Key
SPEED SEL Key
RS-232 DLM Key
.............................................
Indicators
TRACK/STATUS
Indicator
Disk Drive Activity
Indicators
Indicators
DRIVE
COPY 11 and
DRIVE 2
TO 2
Indicator
DISK INITL Indicator •••••.•••••••..••••••••••••••••••
ON-STOP/OFF-CONT Indicator ••••••••.••••••••••••••••••
READ DISK Indicator
WRITE DISK Indicator
.................................
READ TRACK Indicator ••••••••••••••.••••••
FIND EVENT Indicator ••••••••••••••••••
ON-RS232/0FF-DLM Indicator ••••••.•••••
REAR Panel Connectors
....................................
i
Page
1-1
1-1
1-2
2-1
2-1
2-2
2-3
2-4
2-5
2-8
2-8
2-10
2-10
2-10
2-11
2-11
2-12
2-13
2-13
2-14
2-14
2-14
2-18
2-18
2-18
2-18
2-19
2-19
2-19
2-19
2-19
2-20
2-20

3.7
IV OPERATOR'S MANUAL
~~JLE OF CONTENTS
(Continued)
CHAPTER 3
OPERATION
c-'" r'-;nnections and Self-Test
_ Interface Connections ••••••••
Initialization and Organization
-~ '"'r! ~_;;er D3ta • • •• • • • • • • • • •. •. • • • • • • • • • • • • • •
~ttended) Data Recording
:so~2~1c (Unattended) Data Recording •••••••••
''',-i -::ca Before Recording
_ew Data After Recording ••••••••••••••••••••
~andalone (RS-232) Recording ••••••••••••••••
Back Data
Track Operations
Event Operations
Forward/ Back Operations
Copying Disks
ration with One Drive Inactive
ii
Page
3-1
3-1
3-2
3-3
3-4
3-4
3-6
3-7
3-8
3-8
3-9
3-10
3-10
3-11
3-12
3-13

MSU IV OPERATOR'S MANUAL
TABLE OF CONTENTS
ILLUSTRATIONS
Figure
1-1
2-1
2-2
2-3
2-4
3-1
3-2
3-3
3-4
3-5
Table
1-1
2-1
2-2
2-3
2-4
2-5
2-6
Digilog MSU IV Mass Storage Unit •••••••••••••••••••••••••
Rear Panel Controls and Connectors •••••••••••••••••••••••
Front Panel Controls and Indicators ••••••••••••••••••••••
Inserting and Removing Diskettes •••••••••••••••••••••••••
Proper Diskette Care .................................... .
MSU IV and DLM Cable Connections •••••••••••••••••••••••••
RS-232 Mode Connections ..••......••.••.••.............••.
View Data Before Recording •••••••••••••••••••••••••••••••
View Data After Recording •.••••••••••••••••••••••••••••••
Standalone (RS-232) Recording ••••••••••••••••••••••••••••
TABLES
MSU lV Specifications and Characteristics ••••••••.•••••••
Error Messages ••••••••••••••••••••••••••••••••••••••••••.
Front Panel Control Keys .••.••....••.•..............•..••
Front Panel Indicators .................................. .
Status Messages •••••••••••••••••••••••.••••••••••••••••••
Speed Selection ......................................... .
Rear Panel Connector Pin Designations •.••••••••••••••••••
iii
Page
1-1
2-1
2-4
2-6
2-7
3-1
3-2
3-7
3-8
3-8
Page
1-2
2-3
2-9
2-15
2-16
2-17
2-20

CHAPTER 1
DESCRIPTION OF EQUIPMENT
:.1 INTRODUCTION
This chapter serves as an introduction to the DIGILOG MASS STORAGE UNIT IV
(MSU IV). This chapter also includes a general description of the MSU IV along
with the list of its characteristics and specifications.
1.2 GENERAL DESCRIPTION
The DIGILOG MSU IV (Figure 1-1) is a compact, low cost mass storage unit
for use with a DIGILOG data line monitor (DLM) or with any vendor's data line
monitor. The MSU IV can be used by relatively unskilled personnel and serves
as an extension of the DLM internal memory. The MSU IV can also be connected
to any RS-232 communication device (modem, terminal, FEP, etc.) for direct
digital recording of data and status information.
MSU IV uses trouble-free, nonvolatile diskettes to provide unattended data
line monitor and the subsequent analysis of long data/control sequences (over
400k bytes). Recording or playback is accomplished in either the standalone
RS-232 or the DLM mode. When operated automatically at speeds up to 19.2 kbps
on FDX lines, the MSU IV will determine the speed of the line from the data
stream. Recording speeds over 19.2 kbps, and up to 72 kbps, can be selected
manually by the user.
Figure 1-1. DIGILOG MSU IV MASS STORAGE UNIT
1-1

HSU IV OPERATOR'S MANUAL
DESCRIPTION OF EQUIPMENT
---: ··.:! '..'.' £'eatures, such as fault isolation, search,
-~ --"' ··~2d to analyze data stored on MSU IV diskettes.
·~ : ~ :-''~~ t. data and status loading from DIGILOG
1 s
line of
-~~~~ or fro~ an RS-232 data line. Dual diskettes provide
·~skette copy capability, back-up, and true continuous
suppression, or
Another feature
data monitoring
added versa-
recording.
~~?~tes recorded on-site may be analyzed at another location by more
:::'.::::•~' ·;v:ced nersonnel. MSU IV can also be used for the recording of
~: :-::-:~:::::_c3tion sequences for use as a data communications training aid.
:isu IV functions automatically under DLM control or may be operated
~anually as a standalone unit by using front panel controls and indicators.
T'.-,e llSU IV is supplied in a self-contained carrying case or may be rack
mounted.
1.3 SPECIFICATIONS AND CHARACTERISTICS
Table 1-1 contains a listing of MSU IV's specifications and characteris-
tics. The table includes information for both operation and power capabilities.
TABLE 1-1. MSU IV SPECIFICATIONS
AND CHARACTERISTICS
DISK STORAGE: 409,600 data characters, 409,600 status bytes
DATA RATE: Recording automatically determined from data stream (on FDX lines
at 19.2 kbps or lower) or set manually from the front panel (above
19.2 kbps to 72 kbps).
RECORD CONTROL: Manual or automatic
RECORDING MEDIA: 5-1/4 inch, dual-sided double density diskettes
DRIVES: 48 TPI, double-sided
TRACK/STATUS DISPLAY: 3-digit, 7-segment
LED INDICATORS: 10
KEY SWITCHES: 12
POWER: 115/220 Volts, 50/60 Hz
DIMENSIONS: Height; 5-3/16 in. (13.5 cm)
Width; 15-1/4 in. (39.0 cm)
Depth; 16 in. (40.5 cm)
MOUNTING: 19-in. rack mounting (optional)
WEIGHT: 22 lb (10.0 kg) with carrying cover
INTERFACE: 1 DIGILOG DLM interface. Direct recording from an RS-232 line
through 2 common connectors (DTE and DCE), 1 playback output
connector.
1-2

CHAPTER 2
CONTROLS, INDICATORS, AND CONNECTORS
2.1 INTRODUCTION
This chapter describes how to select MSU IV operating voltage, how to
change the unit's fuse, and how to apply power. Included are descriptions of
the unit's controls, indicators, and connectors. Descriptions of status
messages are also included.
2.2 OPERATING VOLTAGE SELECTION AND FUSE REPLACEMENT
MSU IV is normally shipped from the factory ready to operate using a
primary source voltage of 115 VAC, 60 Hz; however, it is designed to operate on
either 115 or 220 VAC at 50 or 60 Hz. Use the following procedure to check or
change the unit's operating voltage configuration. Use Figure 2-1 to locate
items referred to in the procedure:
*WARNING*
POWER SOURCE VOLTAGE IS ALWAYS PRESENT IN TERMINALS
INCLUDING THE POWER INPUT CONNECTOR, FUSEHOLDER,
POWER SWITCH, ETC. POWER SOURCE VOLTAGE MAY RESULT
IN PERSONAL INJURY OR DEATH WHEN CONTACTED.
DIG I LOG
DLMINTERFACE
CONNECTOR
DATA
TERMINAL
EQUIPMENT
CONNECTOR
DATA
COMMUNICATION
EQUIPMENT
CONNECTOR
D
POWER SWITCH FUSE HOLDER
OUTPUT
CONNECTOR
D
ITO
O''°
HL()
115 VAC: 1.5A SLO·BLO
220 VAC: 0.75A SLOW·BLO
VOLTAGE
SELECT
SLIDE
SWITCH
AC LINE CORD
FIGURE 2-1. REAR PANEL CONTROLS AND CONNECTORS
2-1

MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
1. Check that MSU IV's line cord is not plugged into an outlet.
2. Check the setting of the rear panel voltage select slide switch. The
number seen, either 115 or 220, must be in the range of the voltage
applied to MSU IV.
3. Set the voltage select switch by moving the slide to one extreme posi-
tion or the other. If MSU IV is being configured to operate in a
range of 95V to 130V, set the switch to 115. If the unit is to
operate at voltages between 190V and 260V, set the switch to 220.
4. Check the rating of the fuse in the fuseholder. If the unit is con-
figured to operate at 115 VAC, 50 to 60 Hz, the fuseholder must con-
tain a 1.5 A slo-blo fuse. If it is configured to operate at 220
VAC, 50 or 60 Hz, then it must contain a 0.75 A slo-blo fuse.
5. Change the fuse by pushing the fuseholder cap in and twisting it clock-
wise to loosen. Replace the fuse with a fuse of the same value.
Slide the fuse back into the fuseholder cap. Push the fuseholder cap
into the fuseholder assembly and twist counterclockwise to seat it in
place.
2.3 APPLYING POWER
Before plugging the line cord into an outlet, refer to paragraph 2.2 and
verify that MSU IV is configured to operate using the voltage supplied by the
outlet. Check that the rear panel POWER switch is set to OFF before plugging
the line cord into the outlet.
Apply power to MSU IV by setting the POWER switch to ON. MSU IV automati-
cally performs both a test of its light-emitting diode (LED) indicators (except
for the disk drive activity indicators) and an internal diagnostic self-test
each time the unit is turned on.
Immediately after the POWER switch is set to ON, verify that MSU IV's front
panel indicators light and that the TRACK/STATUS indicator displays 888. A LED
failure may cause an incorrect indication during system testing, but this does
not mean that the unit cannot be used; however, it does mean that the indicator
should be repaired as soon as possible.
Upon completion of the indicator test, DRIVE 1, CONT, and TRACK/STATUS
indicators remain lit (the TRACK/STATUS indicator displays 00) and all other
indicators go out.
If the unit should fail the internal self-test, the TRACK/STATUS indicator
displays the letter E and a two-digit error message. Refer to Table 2-1 for a
description of diagnostic error messages. During self-test, MSU IV also per-
forms a test of its own random-access memory (RAM) and erasable programmable
read only memory (EPROM). If a RAM or EPROM problem is detected, an error
message is displayed on the TRACK/STATUS indicator; refer to Table 2-1.
2-2

MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
Error messages do not prevent MSU IV from being used. It is up to the user
to decide if a unit displaying an error message is suitable for use. Since a
RAM error (S07) or a EPROM error (S08) can result in defective data, it is
recommended that an MSU IV displaying this characteristic not be used.
DESCRIPTION
E01
E02
E03
E04
E05
E06
E07
E08
S07
sos
TABLE 2-1. ERROR MESSAGES
MEANING
Faulty disk-to-memory
data transfer.
CRC error on diskette.
E01 and E02.
I.D. not found on diskette.
E01 and E04.
E02 and E04.
E01 and E02 and E04.
MSU IV mode plus diskette
type match.
RAM error during diagnostics.
EPROM error during
diagnostics.
CORRECTIVE ACTION
Have MSU IV serviced.
Replace diskette.
Have MSU IV serviced.
Initialize diskette. If it has
been initialized, replace it.
Replace diskette; if error re-
peats have MSU IV serviced.
Replace diskette.
Replace diskette; if error re-
peats have MSU IV serviced.
Select proper mode or use
proper diskette.
Have MSU IV serviced.
Have MSU IV serviced.
2.4 FRONT PANEL DISK DRIVES, CONTROL KEYS, AND INDICATORS
The following paragraphs contain functional descriptions of MSU IV's front
panel disk drives, control keys, and indicators. Figure 2-2 illustrates MSU
IV's front panel.
2-3

DISKETTE DRIVE 1
MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
FUNCTION INDICATORS DISKETTE
DRIVE 2
,A
r '
~U IV MASS STORAGE UNIT
ON AS732 ON STOP READ WAITF. READ FIND COPY DISK
CIGILCG
0 0 0 0 0 0 0 0
OFF OLM OFf- CUNT DISK DISK TRACK EVENT 1 TO 2 INITL
l D~l 1 J D~E2 1 I
TRACK STATUS
g
ODD
g~
r'
~
ODD
r.'
J
~
ODD
~
og_o
_S
~
\
~
~·
ACTIVITY INDICATOR CONTROL KEYS
ACTIVITY INDICATOR
FIGURE 2-2. FRONT PANEL CONTROLS AND INDICATORS
2.4.1 Disk Drive Units
*CAUTION*
DO NOT TRANSPORT MSU IV WITH DRIVE LATCHES CLOSED,
OR WITH MEDIA IN THE DRIVES. THIS CAN RESULT IN
DAMAGE TO THE DISK DRIVE UNITS.
Two disk drive units are provided, one on each side of the key panel. This
paragraph explains how to insert a diskette into a drive and provides informa-
tion on the care and handling of diskettes.
To open a disk drive, carefully pull and lift the drive latch to the open
position; see Figure 2-3. Hold the diskette so that the tab (or notch) is to
the left. Insert the diskette into the open drive and ensure that it is firmly
seated. Carefully close the latch; the latch is properly closed when a click
is heard.
2-4

MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
*CAUTION*
NEVER OPEN A DISK DRIVE UNIT WHILE THE ACTIVITY
LIGHT IS ON. THIS WILL CAUSE DATA TO BE LOST,
AND COULD CAUSE DAMAGE TO THE DISKETTE.
The tab shown in Figure 2-3 covers the write protect notch. If the tab is
attached, the diskette can only be read from, not written to. Any attempt to
write to a protected diskette (tab present) will result in an 305 status
message and no subsequent operation. To write to a protected diskette, first
carefully remove the tab.
Each disk drive has an activity indicator. When lit (red), the activity
indicator shows that read, write, or seek operations are taking place in that
drive. Do not remove diskettes while activity indicator is lit.
In addition to the activity indicators, MSU IV contains DRIVE 1 and DRIVE 2
selection indicators (paragraph 2.4.3.3) plus READ and WRITE selection indi-
cators (paragraph 2.4.3.7) to inform the operator of each disk drive's status.
All MSU IV indicators, however, relate to disk drive functions and activity;
refer to paragraph 2.4.3 for complete information.
Diskettes can be easily damaged if mistreated. There are certain precau-
tionary measures that must be taken to preserve diskette reliability; refer to
Figure 2-4 for proper diskette care.
2.4.2 Control Keys
Twelve control keys are used to set up and operate MSU IV. As shown in
Figure 2-2, the keys are grouped together on th MSU IV's front panel. Table
2-2 contains a listing of the keys along with a brief description of each key's
function.
In the following paragraphs, each control key is discussed as to its
relationship to various indicators as well as to its relationship to MSU IV
operating modes.
2-5

MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
FIGURE 2-3. INSERTING AND REMOVING DISKETTES
2-6

MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
PROTECT THE DISKETTE. Restrict
eating, drinking and smoking to other
areas. Keep the diskette free of dust.
DO NOT EXPOSE TO ANY MAGNETIC
Fl ELOS. Data can be lost if the diskette
is exposed to electric or magnetic fields
or stored in a low humidity environment
where static electricity is easily generated.
Keep the humidity at a reasonable level.
HANDLE GENTLY. Do not touch the
diskette's magnetic surface. Never clip,
staple, or otherwise damage the card·
board cover. When labeling, use labels
supplied by the manufacturer and write
on them with a soft felt·tip pen. Do
not remove the disk from a drive when
the indicator light is on.
STORE IN A SAFE PLACE. Temperatures
in the storage area are to be kept between
10°c -5o0c (50°F - 120°F). Do not
expose to direct sunlight and avoid areas
where condens3tion may occur. Always
store diskettes in their jackets, labeled,
and in an appropriate storage medium;
i.e., a diskette box or binder.
FIGURE 2-4. PROPER DISKETTE CARE
2-7

MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
2.4.2.1 RUN and HALT Keys
Keys RUN and HALT control transferring operation from standby to operate,
and back to standby; refer to Table 2-2. These keys are active in the RS-232
and DLM operating modes. When an operating mode is selected using a key, the
appropriate LED from the list below begins to blink:
1. COPY 1 TO 2*
4. WRITE/DISK
2. DISK INITL*
5. READ TRACK*
3. READ/DISK
6. FIND EVENT*
This is a standby or idle condition. When the RUN key is pressed, the
blinking LED lights steadily and the associated operation begins.
Depressing the HALT key while any of the above operations are on stops the
operation at the end of that I/0 cycle and then causes the LED to return to the
blinking condition.
If MSU IV is performing a write operation, pressing HALT key, in addition
to stopping the unit, places an end of data mark (S02) at that track location.
The event mark is used by MSU IV to identify the end of recorded data.
When READ TRACK indicator is lighted steadily, each pressing of the RUN key
causes a block (track) of data to be read.
When FIND EVENT indicator is blinking, pressing RUN key causes MSU IV to
search for event markers. Upon detection of an event mark, the unit displays
status message S01, S02, or S03, and the FIND EVENT indicator returns to blink-
ing. MSU IV is now prepared to read data from the beginning of the track
containing the event mark.
When used with a DLM the MSU IV stops reading data when the DLM detects a
pre-programmed trap or error condition; the reading sequence, however, need
not be interrupted. No characters are lost during a read if a halt occurs at
the DLM. Assuming that a continuous read operation is desired, when the DLM is
started again after the halt, characters sent to the DLM are contiguous and
there are no gaps in the data.
2.4.2.2 DISK INITL Key
The DISK INITL key introduces a mode of operation that causes a diskette
inserted in a drive to be formatted (initialized) for use in MSU IV; refer to
Table 2-2.
*A second pressing of this key, performed-while the key's associated indicator
is blinking, turns off the selected mode and related indicator.
2-8

KEY
LEGEND
RUN
HALT
DISK
IN I TL
DRIVE
SEL
READ
WRITE
STOP
CONT
EVENT
MARK
OPER
SEL
DRIVE
SEL
TRACK
FWD
TRACK
BACK
RS-232
MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
TABLE 2-2. FRONT PANEL CONTROL KEYS
FUNCTIONAL
DESCRIPTION
Starts operation of
selected mode
as indicated
by a lighted indicator.
Stops operation of mode indicated
by
lighted
indicator. Returns
mode indicator to blinking.
Selects disk initialization mode for blank diskette in selected
drive;
DISK INITL indicator blinks.
Run key
starts initialization;
DISK INITL
indicator lights steadily.
Alternate pressings select
either drive
1
or drive 2.
DRIVE 1
or
DRIVE 2 indicators light to indicate selected
unit.
Alternate pressings select either read or write modes of operation
for
selected drive;
READ or WRITE indicators
(as appropriate)
blink.
RUN key starts the selected operation;
READ or WRITE indicator light
steadily. Depressing
READ WRITE key overrides other selected
(blinking indioator)
modes.
Alternate pressings select either
continuous operation,
wherein data
recording is alternated between drives
(CONT indicator lit); or
stop-full recording, wherein MSU IV stops recording when enabled
diskette is full
(ON-STOP indicator lit).
Pressing key marks track near data sequence
of interest as it is
written to diskette.
This event mark can be searched
for
during
playback.
EVENT MARK key is active only in
write mode.
Selects
search mode of operation;
read track,
find events,
or copy 1
to 2.
The selected mode indicator starts blinking.
Alternate pressings select
either drive
1
or drive 2.
DRIVE SEL key
is active in all modes.
Sequential
pressings of this key increment the track number.
Holding
key pressed
for longer than one second
causes track number
to
increment at about
10 per
second. Track number is shown on TRACK/
STATUS indicator.
Same as TRACK FWD key,
except that track number decrements.
Alternate
pressings
select either
the
RS-232 standalone
recording mode
or the DLM recording mode.
The ON-RS232 indicator is
lit when the
RS-232 mode is selected.
2-9
s

MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
After a diskette is inserted into the selected drive (paragraph 2.4.2) and
DISK INITL key is pressed, the DISK INITL indicator begins blinking and any
other previously blinking LEDs go out. Pressing RUN key starts the initiali-
zation process and the DISK INITL indicator lights steadily.
When the initialization process terminates, the DISK INITL indicator
returns to blinking; the initialized diskette may now be removed from the drive.
2.4.2.3 DRIVE SEL Key
The DRIVE SEL key is active whenever any of the indicators are blinking
(standby); refer to Table 2-2. Sequentially pressing the DRIVE SEL key under
this condition alternately selects drive 1 (DRIVE 1 indicator lit) or drive 2
(DRIVE 2 indicator lit). Refer to paragraph 2.4.1 for a discussion of the disk
drives.
2.4.2.4 READ WRITE Key
Sequential pressings of the READ WRITE key alternately introduce the data
read mode (READ indicator blinking) or the data write mode (WRITE indicator
blinking). Any other indicators that are blinking go out.
To activate the read or write modes, press the RUN key. A steadily lighted
READ or WRITE indicator means that the operation is in progress; refer to Table
2-2.
When indicator READ is blinking, MSU IV is ready to send data from its
disks to the DLM capture buffer for display and/or analysis on the DLM screen;
refer to paragraph 3-5. When indicator WRITE is blinking, MSU IV is ready to
begin receiving data.
2.4.2.5 STOP/CONT Key
Sequential pressings of the STOP/CONT key alternately selects either a
continuous recording mode (OFF-CONT indicator not lit) or a stop-full mode (ON-
STOP indicator lit); refer to Table 2-2.
In the continuous recording mode, drives 1 and 2 alternate operation as the
diskette in each becomes full. DRIVE 1 or DRIVE 2 indicators light to indicate
the drive in operation. The operator may either remove a full diskette and
replace it with an initialized blank one, or allow data on a full diskette to
be written over in subsequent write cycles. If the diskettes aren't removed,
data already recorded are replaced by the new data, and the old data are lost;
refer to paragraph 2.4.2.
In the stop-full (fixed length) mode, the write operation stops when both
diskettes are full or the other drive is not in the ready state (door open, no
diskette in drive); the WRITE DISK indicator then begins to blink. The
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MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
operator may either replace the diskettes with initialized blank ones or
continue to use the diskettes already in the drives as described for continuous
recording above.
The continuous recording mode can be used with only one drive. Select the
drive to be used (refer to paragraph 2.4.2.3), and then select either the
continuous or stop-full operating mode. Replace the diskette or continue
recording when the WRITE DISK indicator begins to blink.
2.4.2.6 EVENT MARK Key
The EVENT MARK key is active only during the write mode (WRITE DISK indi-
cator lit); refer to Table 2-2.
Pressing the EVENT MARK key places an event mark (S01) near a sequence of
data characters recorded on the diskette; that is, the key is used to mark a
track of interest. Multiple tracks may be marked. During playback, the
diskette can be returned to a marked track by using the OPER SEL key.
2.4.2.7 OPER SEL Key
Sequential pressings of the OPER SEL key selects either the READ TRACK,
FIND EVENT, or the COPY 1 TO 2 mode of operation. The indicator for the
selected mode will start blinking.
Pressing the OPER SEL key until the READ TRACK indicator starts blinking
introduces a one-track read mode. Any other blinking indicators go out; refer
to Table 2-2.
To read the track of data shown on the TRACK/STATUS indicator, press RUN
key. A steadily lighted READ TRACK indicator means that the track is being
read, and MSU IV sends (reads) as many as 2,500 characters to the DLM capture
buffer; refer to paragraph 2.4.2.4.
After the track is read, the drive stops and READ TRACK indicator begins
blinking. READ TRACK can be used with OPER SEL key to read marked data; refer
to paragraph 2.4.2.7.
The FIND EVENT mode is active only during the read mode (READ DISK
indicator lit); refer to Table 2-2.
*NOTE*
MSU IV SEARCHS FOR EVENT MARKS S01 AND S02 WHEN
PERFORMING FIND EVENT OPERATIONS.
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MSU IV OPERATOR'S MANUAL
CONTROLS, INDICATORS, AND CONNECTORS
To locate event marks on a diskette of recorded data, place MSU IV in the
read mode and then press OPER SEL key sequentially so that indicator FIND EVENT
starts blinking. Next, press RUN key to start the find event operation; indi-
cator FIND EVENT lights steadily, and TRACK/STATUS indicator begins increment-
ing. The diskette is now being searched in the direction of increasing track
number for an event marker, and four things can happen:
1. The TRACK/STATUS indicator cycles continuously, and gives no indica-
tion of ever stopping. This can be caused by the absence of event
marks on the diskette; press HALT key to exit FIND EVENT mode.
2. The TRACK/STATUS indicator displays message S01, and indicator FIND
EVENT starts blinking. This situation means that a track of data
containing an event mark inserted by EVENT MARK key was found.
In order to search for the next event mark return to the FIND EVENT
mode after performing one of the following actions; either do a
READ DISK or READ TRACK operation, or use TRACK FWD key to increment
the TRACK/STATUS indicator by one.
3. The TRACK/STATUS indicator displays message S02, and indicator FIND
EVENT starts blinking. This situation means that an end of recorded
data mark has been found. Press RUN key to search for the next
event marker, or press READ key to begin reading data.
4. The TRACK/STATUS indicator displays message S03, and indicator FIND
EVENT starts blinking. This situation means that both an event
mark and an end of recorded data mark have been found on the same
track; proceed as described in 1 and/or 2 above.
Pressing OPER SEL key for the COPY 1 TO 2 mode causes the diskette dupli-
cation mode to be introduced (COPY 1 TO 2 indicator starts blinking); refer to
paragraph 2-2.
Data on a diskette loaded into drive 1 will be written to a formatted
diskette loaded into drive 2 when RUN key is pressed (COPY 1 TO 2 indicator
lights steadily). When the copying operation is complete, COPY 1 TO 2
indicator returns to blinking condition; refer to paragraph 2.4.1.
A copy may be started from any track location of drive 1 to starting at any
track location of drive 2. Copying will stop at the last data track (079) of
the diskette in either drive.
2.4.2.8 TRACK FWD Key
The TRACK FWD key is active whenever an indicator (except DISK INITL and
COPY 1 TO 2) is blinking; refer to Table 2-2.
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