Sanders Associates Sanders 620 User manual
SANDERS
620*
I
STAND-ALONE DATA DISPLAY SYSTEM
MANUAL
HOME OFFICE
CENTRAL COMPUTER
BULK
STORAGE RECORD
BRANCH OFFICE
REMOTE
620
SYSTEM
Sanders
620
Display
is
prepared
to meet
your
total system
needs
...
for
stand-alone terminals.
..
a cluster
of
terminals .
..
or
both
.
..
in a local
or
nationwide network
of
instant computercommunications
.---------IfiiY
\ WAREHOUSE
lW
~
SALES OFFICE
"EMOTE fl20 SYSTEM
REGIONAL HEADQUARTERS
620
MULTISTATION SYSTEM
UP TO
18
DISPLAYS
PER SERIAL DISTRIBUTOR
MODEL
620
STAND·ALONE
DATA
DISPLAY
SYSTEM
MANUAL
FEBRUARY
1969
REVISION 2
SANDERS
ASSOCIATES,
INC.
DATA SYSTEMS DIVISION
D.W. HIGHWAY SOUTH, NASHUA, N.H.
03060
-T.M.
Sanders
Associates,
Inc.
"THII
DOCUMENT
CONTAINI
PROPRIETARY
INFORMATION
OF
IANDERI
AIIOCIATEI. IHC.
AHD
II
TO
BE
UIED
ONLY
FOR
THE
PURPOIE
FOR
WHICH
IT
HAl
BEEN
IUPPLIED
THII
DOCUMENT
II
NOT
TO
BE
DUPLICATED
IN
WHOLE
OR
IN
PART
wiTHOUT
PRIOR
wRITTEN
PERMIIIION
FROM.
DULY
AUTHORIZED
REPREIENTATIVE
OF
IANDERI
AIIO·
CIA
TEl. INC"
5'·00·614
(8·67)
INTRODUCTION
This
manual contains a detailed component
description
of the
Sanders'
620
Data
Display System
as
well
as
programming
considerations
for
the 620 with IBM
System/360.
The information
is
to be
regarded
as
proprietary
and
is
to be
used
only
for
the
purpose
for
which
it
has
been supplied. This document
is
not to
be
duplicated in whole
or
in
part
with-
out
prior
written
permission
from
a duly
authorized
representative
of
Sanders
Associates,
Inc.
i
TABLE
OF
CONTENTS
Section 1
Functional
Description
• • • . • • • . . • • • . • . • . . . • . • 1
Section 2
System
Configuration .
I/O
Section • • • • •
Edit
Section
Memory
Access
Section •
Memory
Section
Display . . .
Power
Supply.
Keyboard
.••
. . . . . . . . . . . . . . . . . .
System
Operation.
. . •
Input/Output
Operation
General
. . . • . . . .
Synchronous
Operation
Asynchronous
Operation
.•.
Communication Sequences .
Non-Response
Mode
Response
Mode .
Error
Checking
Edit
Operation
.
Format
Type Mode •
Section 3
ii
. ..
• • 2
• • 2
• • 2
• • • • • 3
• • • • 3
. 4
• • 4
• • 4
• • • • 5
• • 5
• • 5
· . • 5
• • 6
• • 6
. 7
• • 9
•
••
12
• .13
• • .13
TABLE
OF
CONTENTS (Cont)
Type Mode
•.•...
Conversation
Type Mode • • • • • • • • • • •
Description
of
Hard
Copy
Option.
• • • • • .
Hard
Copy Option
Components.
•
Hard
Copy Buffer I
.•
••
Printer
Transmission
Cable
Keyboard
....•
Hard
Copy Functional
Operation
••
Hard
Copy Code
Conversion.
. .
Hard
Copy Modes
of
Operation.
. .
Section
4
Programming
Considerations
for
Use
of 620 with IBM
System/360.
•
Remote
Transmission
-(2400
Bits
per
second
or
less)
• •
OS
BTAM -(Remote Connection)
•••••
• • • •
OS
QTAM -(Remote Connection)
DOS
BTAM -(Remote Connection) •
DOS
QT
AM
-(Remote Gonnection) •
Device Dependent Module
(DDM)
Description
Detailed
Message
Structures
-
Remote
Operation
Access-Method
Dependent
Information
Using
a
DDM
•••
.
•..
Message
Processing
Macros
EDITMOVE
Macro
-Instruction
TABLES
Macro-Instruction
. • • •
Section
5
Timing
Considerations
for
620
Control
Operations
•
Format
Type Mode • . • • • • • •
Type Mode
Conversation
Type Mode
Table
of f
Values
•••••
iii
14
17
18
18
18
19
19
19
19
19
20
21
21
21
22
23
24
25
25
26
26
27
27
28
29
30
30
31
32
TABLE
OF
CONTENTS (Cont)
Section 6
Interface
Requirements
and
Characteristics
Hardware
Interface
Data
Set
Interface
• •
Serial
Distributor
Interface
Software
Interface
with IBM
System/360
Special
OS
System
Generation
Considerations
BTAM and QTAM-Remote Connection
Caution
Special
DOS
System
Generation
Considerations
BTAM and QTAM-Remote Connection
Caution
Section
7
Installation
Planning
Data
Input
Power
Requirements
Physical
Specifications.
•
Display
Terminal
• • • •
Dimensions
and Weight ·
Connectors
. . · ·
Cables
· ·
Keyboard . · ·
Dimensions
and Weight ·
Connectors
. · ·
Function Keys
Environmental
Conditions
Operating
•
Storage
·
·
·
·
·
·
· · · · · ·
· · · ·
· · · · · · · ·
· · · · · ·
· · · · · ·
· · · · · · ·
iv
· ·
· ·
· ·
· ·
33
33
33
33
34
34
34
34
34
34
35
36
36
36
36
36
36
36
37
37
37
37
37
37
37
A.
B.
C.
D.
E.
F.
G.
H.
APPENDIX
620
Control
-
Character
Abbreviations
620 CODE TABLE -(USASCn SUBSET)
620
Keyboard
••••.•••••••
620
Character-Generator
Racetrack
Schematic
Table
of
620
Control
Operations
Comparison
Table
-620/720
Message
Formats
• • • • • •
Translation
Tables
-(ASCn-8
to
EBCDIC
and
EBCDIC
to
ASCn-8)
Glossary
of
Terms
• . • • • • • • • • • • • • • • • • • • •
v
38
39
40
41
• • • • •
42
• • • • •
43
• • • • • 44
• • • •
46
SECTION 1
FUNCTIONAL DESCRIPTION
The
620
is
a desk-top
stand-alone
alphanumeric CRT
display.
It
has
a 780-
character
programmable
memory
and
the optional capability of writing into
anyone
of
over
2,000
screen
locations. Optional edit
features
include Horizontal and
Vertical
tabs,
fixed and
variable
data
blocks, and conversation mode. All
I/O,
editing,
memory,
display
and power supply components
are
self-contained in a single
terminal
package.
It
is
designed to
operate
in a
remote
environment
via
data
set
modem connection to a digital
Central
Processor.
The
620
keyboard contains alphanumeric and· control function keys
as
defined by
Appendix C. Data
entry
via
the
keyboard
causes
screen
character
generation
or
function
control to
occur
simultaneously with each
keystroke.
Hardcopy may be added to the 620 with the
use
of
the hardcopy adapter and a
tele-
printer.
The
remote
user
may
initiate
the copy
of
either
variable
block information
or
the
entire
screen
content by
depressing
the function keys
associated
with those
operations.
The computer may poll and
initiate
a
printing
sequence by
inserting
a
print
command
instruction
prior
to the ETX of
its
outbound
message.
Data
transmission
may be on a polled
Or
a contention
basis
and can be
either
synchronous
or
asynchronous. A
subset
of Standard USASCn Code
is
used
for
all
data
transmission
and the data
set
interconnection
meets
EIA
standard
RS
232
B Specifications.
1
SECTION 2
SYSTEM CONFIGURATION
The 620
System
consists
of
seven
functional
blocks.
They
are:
1.
I/O
Section,
2. Edit Section, 3.
Memory
Access
Section, 4.
Memory
Section, 5.
Display
Section,
6.
Power
Supply, and 7. Keyboard.
I/O
SECTION
The function
of
the
I/O
Section
is
to
control
the
transfer
of
data
between a
data
set
and the 620
System.
The
I/O
Section
performs
the following functions:
a.
Generates
character
parity
and LRC
,on
the outbound
messages.
b.
Checks
for
parity
error
and
LRC
error
on incoming
messages.
c.
Decodes the
header
sequence
and
recognizes
a
specific
address
for
inbound
messages.
d.
Encodes
the
header
sequence
for
outbound
messages.
e.
Provides
logic
level
conversion
and
synchronization
with the
Data
Set.
EDIT SECTION
The function of the Edit Section
is
to
perform
all
editing
operations
for
data
re-
ceived
from
either
the
keyboard
or
the
computer,
and
for
all
data
sent
to the
computer.
The
basic
edit
function
provides
the capability
of
entering
data
on the
screen
from
left
to
right
and
top to bottom
through
780
locations.
All
entry
is
in
format
type mode.
2
Optional Edit
features
include:
• Horizontal and
Vertical
Tab
--
where a
HT
causes
the
cursor
to move 4
•
•
screen
spaces
to the
right
of the
starting
location and
inserts
1
HT
character
on the delay line, and a VT
causes
the
cursor
to move 4
lines
down (to the
beginning of the new line) on the
screen
and
inserts
1 VT
character
on the
delay
line.
All 2,000 +
screen
locations
are
accessible
with
this
option.
Conversation
Mode
--
where
each
alternate
Computer/User
entry
is
auto-
matically
positioned
at
the beginning of a
successive
line.
For
example,
the
user
may
enter
data
on line 1, the computer automatically
uses
line 2
for
its
reply; the
user
then
is
positioned to line 3
for
his
next
entry,
the
computer then
replies
on line 4, and
so
on.
Format
Mode -- where
start
delta
I> and stop
delta
<I
are
used
to define
variable
data-entry
fields.
Under
format
control,
the
user
is
automatically
prohibited
from
writing into any
fields
other than those defined by the
start
and stop
delta
characters.
The completion
of
one field
causes
the
cursor
to automatically move to the beginning of the next available field, (if
there
is
one available), defined by
deltas.
Format
Mode keys
are
provided to allow
the
use
of
these
Edit options.
New
formats
are
created
in
Format
mode by
programming/systems
personnel
and
can then be
used
in Type Mode by the
operators.
HT
and VT
are
considered
Format
Mode
keys.
MEMORY
ACCESS SECTION
The function of the
memory
access
section
is
to provide the
interface
between the
620
Memory and the Edit
and/or
Display
sections.
MEMORY
SECTION
The function of the
memory
section
is
to
store
all
alphanumeric and function-
control
characters
required
to
format,
edit, and
generate
a display.
Either
the
total
contents
or
the delta-defined
data
blocks
of
tl1e
memory
may be dumped to the
tele-
communications
line.
3
DISPLAY SECTION
The function of the
display
section
is
to
provide
a
visual
representation
of the
data
stored
in
memory
on the
face
of
the
CRT.
POWER SUPPLY
The function of the
power
supply
is
to
provide
the
proper
voltage
and
current
requirements
to
each
of
the
other
operating
sections.
KEYBOARD
The function of
the
keyboard
is
to enable
the
operator
to
enter,
display,
and
trans-
mit
data
through
the 620
System.
The
keyboard
is
provided
with
electrical
interlock
such
that
the
first
key-depressed
will be
entered
into
memory.
A two
key
roll-off
feature
is
provided
so
that
if
two
keys
are
depressed,
the
second
key
will not be
entered
into
memory
until
the
first
key
is
released.
There
are
42
alphanumeric
and
special
symbol
keys,
19
control
keys
and
a
space
bar.
One of
the
control.
keys
is
a
repeat
key
which, when
depressed
along with a
second
key,
will make
repeated
entries
at
a 30
cps
rate.
Cycle
left
and Cycle
right
keys
are
also
provided
to
aid
rapid
cursor
movement
through
screen
locations.
4
SECTION 3
SYSTEM OPERATION
Note: Available 620
Screen
matrices
include:
64
characters/line
by
32
lines
(Horizontal
Screen)
52
characters/line
by
40
lines
(Vertical
Screen)
84
characters/line
by
32
lines
(Expanded
Horizontal
Screen)
These
matrix
options
may
be
regarded
as
defining
the
screen
record
positions
into
which
data
may
be
written,
and although
the
following
information
is
based
on a 64 x
32
matrix,
the
same
operating
ponsiderations
apply
to
the
alternative
matrices.
,-
General
The
system
operation
is
described
in
three
sections,
(1)
I/O
Operation,
(2)
Edit
Operation,
and
(3)
Description
of
Hard
Copy Option. Appendix B
identifies
the
codes
that
are
used
in
the
620
system
0
INPUT/OUTPUT
OPERATION
GENERAL
The
620
display
operates
as
a
remote
terminal
capable
of
transmission
and
reception
of
serial
data
at
rates
up to 2400
bits
per
second
(bps).
The
620
may
be
connected
to a
modem,
or
a
number
of
620's
may
be
connected
to
a
modem
via
a
Sanders
Associates,
Inc.
Model 716
Serial
Distributor.
The
modem
being
used
determines
the
data
transfer
rate
and
dictates
whether
data
transfer
is
to
be
effected
in
the
synchronous
or
asynchronous
mode.
SYNCHRONOUS OPERATION
In
the
synchronous
mode,
all
characters
transferred
contain
eight
bits.
Seven of
the
eight
bits
in
each
character
are
data
bits,
and
the
eighth
bit
is
a
vertical
parity
bit.
In
this
mode,
transmit
and
receive
clocks
must
be
provided
to
the
620 by
the
modem.
Each
message
sent
to
the
620
must
be
preceded
by
at
least
two
successive
ASCII SYNC
char-
acters.
Each
message
sent
by
the
620 will,
in
turn,
be
preceded
by
from
two to
four
successive
SYNC
characters,
the
exact
number
being
a 620 option.
Once
synchronization
5
has
been
established,
there
can
be
no
time
gaps
between
bits
or
words.
Synchronous
communication
takes
place
at
a
rate
of 2000
or
2400
bits
per
second.
ASYNCHRONOUS OPERATION
In
the
Asynchronous
mode, a
ten
or
an
eleven
bit
character
is
used.
This
character
consists
of
seven
data
bits,
one
vertical
parity
bit,
one
start
bit,
and one
or
two stop
bits,
the
exact
number
of
stop
bits
being a 620 option.
Asynchronous
communication
is
also
referred
to
as
"start-stop"
communication.
SYNC
characters
are
not
used,
but
rather
the
start
bit
of
each
character
is
used
for
synchronization;
therefore
characters
need
not
follow
each
other
at
a fixed
succession
rate
because
synchronization
is
reestablished
with
each
start
bit.
In
the
asynchronous
mode,
the
620
uses
an
internal
clock
in
transmission
and
reception
of
data.
Data
transmission
rates
from
110 to 2400
bits
per
second
may
be
used.
The
transmission
rate
is
established
by
selection
of
the
appropriate
jumper
con-
nections
on
the
printed
circuit
I/O
card.
COMMUNICATION SEQUENCES
Either
of two
basic
communication
sequences
is
available
in
the
620.
There
is
a
response
sequence
and a
non-response
sequence.
These
sequences
are
620
options.
The
basic
difference
between
them
is
that
the
response
sequence
requires
use
of
longitudinal
redundancy
checks
and
message
acknowledgements which
are
not
required
when the non-
response
sequence
is
used.
In both the
response
and
non-response
modes,
there
are
two
basic
operations
which
may be
performed.
These
are
the
poll
and
write
operations.
The
poll
operation
is
a
request
by
the
CPU
for
data
from
the 620 while the
write
involves
transmission
of
data
from
the
CPU to the 620.
In both
the
response
and
non-response
modes, a
poll
or
a
write
must
be
initiated
by the CPU which
transmits
a
four-character
command
sequence
to the 620.
This
com-
mand
sequence
may
also
be
referred
to
as
an
addressing
sequence.
The
four
characters
of
this
sequence
are
as
follows:
a.
SOH
(Start
of
Header)
b.
CUA
(620
address)
c.
X
'09'
(unused
address
when addreSSing 620)
d.
COMMAND
(Write
or
Poll)
6
The
CUA
(Control Unit
Address)
for
the 620
may
be any of
the
128
possible
USASCII
characters,
but not SYNC
or
EaT.
Each
620
is
hard
wired
to
accept
one and only one
such
address.
Any
command
sequence
containing an
address
other
than
that
associated
with a given 620 will be
ignored
by
that
620.
This
feature
permits
use
of
the
620 with the
Model 716
Serial
Data
Distributor.
If
a
command
sequence
is
received
by a
number
of
displays,
only
the
display
whose
address
corresponds
to
the
CUA
of
the
command
se-
quence will
recognize
the
command.
The
DUA
(Display Unit
Address)
or
second-level
address
of
the
command
sequence
is
used
primarily
for
compatibility
with
Sanders
720/360
message
structures.
The DUA
in
a
command
sequence
sent
to any 620
must
be
the
620 code
for
horizontal
tab.
(This
is
purely
arbitrary
and, of
course,
does
not
result
in
writing
a
horizontal
tab
on
the
dis-
play
screen.)
This
code will
also
be
the
second
level
address
sent
by any 620 in
trans-
mission.
The
command
itself
is
the
fourth
character
of
the
command
sequence.
Only two
commands
are
recognized,
the
WRITE and the
POLL.
All
other
codes
received
at
this
point
result
in
no
operation.
There
is
one
case
in which an
operation
may
begin without
initiation
of a
command
sequence
by
the
CPU
..
If
it
is
desired
that
a
system
operate
on a contention
(i.
e.,
non-
polling)
basis,
the
620 contention option
may
be
enabled
to allow
the
display
terminal
to
transmit
data
upon
operation
of
the "send"
key
on
the
keyboard.
With
this
option enabled,
transmission
takes
place
without
receipt
of a
poll
from
the
CPU.
Non-Response Mode
Write
Operation
--
In
the
non-response
write
operation,
the
CPU
initiates
the
WRITE
command
sequence
and
follows
this
immediately
with a
start
of
text
(STX)
character.
Following
the
STX
from
the
CPU
is
the
message
which
is
terminated
by
an
end of
the
text
(ETX)
character.
The
entire
sequence
is
then
terminated
by
an
end of
transmission
(EaT)
character
from
the
CPU. The full
sequence
is
as
follows:
Computer
to 620
SOH
CUA
X
'Og'
I
7
WRITE (Command)
STX
Message
ETX
EOT
Poll
Operation
--
In
the
non-response
poll
operaU,on,
tPe
C~U
command
sequence
:
..
~:\
".
e~ds
with
the
POLL
character.
At
this
point,
if
the
6~0
ha,~no
message
to
transmit,
it
responds
with
an
EOT.
If
the
620
does
have a
message
to-transmit,
-
it
responds
with STX,
CUA, X '09' ,
message,
ETX,
and
EOT.
The
full
sequenc~
if;$_
shown
~_
the
table
below.
In
the
example
shown, the 620
has
no
message
at
the
end
of
the'
first
poll,
but
does
have a
message
at
the
end
of the
second
poll.
Poll
No.1
Poll
No.2
Computer
to
620
SOH
CUA
X '09'
POLL
(Command)
f
,
SOH
CUA
X '09'
PQLL
(Command)
620
to
Computer
i
EOT
,
STX
CUA
X '09'
message
ETX
EOT
Contention
...
-In contention,
the
620
transmits
upon
depression
of
the
keyboard
SEND
key.
The
sequence
is
shown
in
the
following
table.
620
to
Computer
STX
CUA
X '09'
I 8
Response Mode
I
Message
ETX
EaT
Write Operation -- The
write
operation in the
response
mode
is
similar
to the
write
in the
non-response
mode.
It
differs,
however, in
certain
respects.
After
receipt
of
the
write
command sequence, the 620
must
respond
to the CPU with a negative acknowledge
(NAK)
or
a positive acknowledge
(ACK)
indicating detection
or
non-detection
of
a
vertical
parity
error
in the command sequence.
If
a
NAK
is
transmitted
by the 620, the CPU
must,
in
turn,
retransmit
the command sequence.
If
an
ACK
is
sent
by
the
620,
the
CPU then
transmits
the
message
sequence: STX,
message,
ETX, LRC. The LRC
character
is
the
longitudinal redundancy
character
accumulated by a longitudinal redundancy check
over
all
characters
from,
but not including, STX up to and including ETX.
If
a longitudinal
or
verti-
cal
parity
error
is
detected
by
the
620,
it
awaits
completion of
the
message
from
the CPU
and
then
responds
to the CPU with a
NAK.
Otherwise,
it
responds
after
message
completion
with
an
ACK. The
NAK
signals
the
CPU to
retransmit
the
message
while the
ACK
signals
the CPU to
transmit
EaT
and end the
write
sequence.
If
the 620
responds
to the
initial
write
command sequence with an
EaT,
it
is
an
indication that a 620
hard
copy (optional)
operation
is
in
process
and
that
the
message
from
the computer cannot be accepted. The
computer
must
re-initiate
the command sequence
to execute the
write.
The table below shows the
write
sequence with the
various
620
responses:
Computer to 620
Sequence No.1
SOH
CUA
X '09'
WRITE (Command)
t
620 to Computer
EDT (Hard-Copy
in
Process)
~-----------------------------~'
9
Computer
to
620
I
Sequence No.2
SOH
CUA
X
'Og'
WRITE (Command)
I
I
SOH
CUA
X 'Og'
'WRITE (Command)
,
J
STX
Message
ETX
LRC
!
620
to
Computer
NAK
(Command Sequence
Error)
I
I
ACK
(Proceed)
I
I
NAK
(Message Sequence
Error)
~--------~----------------~I
STX
Message
E'TX
LRC
I
EOT
I
ACK
(Proceed)
I
Poll
Operation
--
The poll
command
sequence
for
the
response
mode
is
the
same
as
for
the
non-response
mode.
If
the 620
has
no
message
it
replies
to
the
poll
with
EOT.
If
the 620
has
a
message
for
the CPU
it
sends
STX, CUA, X'Og',
Message,
ETX,
hRq.
The LRC
is
accumulated
from,
but not including STX, up to and including ETX;
The CPU
responds
to
the 620
Message
with
ACK
or
NAK
according
to
the
results
of
the longitudinal and
vertical
parity
checks
at
the CPU
interface.
A
NAK
signals
the 620
to
retransmit
the
full
message
while ACK
calls
for
620
transmission
of an
EOT
to
terminate
the
entire
sequence.
The table below
illustrates
the
response
poll
sequence:
10
Computer to 620
Sequence No.1
SOH
CUA
X
'09'
POLL (Command)
,
,
Sequence No.2
SOH
CUA
X '09'
POLL (Command)
t
I
NAK
(620
Message
Error)
620
to
Computer
,
EOT
(no
message)
1
,
STX
CUA
X '09'
Message
ETX
LRC
STx
CUA
X '09'
Message
ETX
__
~
____
~+-
______________
~LRC
ACK
(no
error)
J
EbT
Contention -- In contention, operation
is
the
same
as
in polling except
that
the
sequence
is
initiated by the 620
message
transmission.
Operation
is
shown
in
the table
below.
Computer to 620
11
620
to
Computer
STX
CUA
X
'09'
Message
ETX
LRC
,
Computer to 620
I
NAK
(620
Message
Error)
I
I
ACK
(no
error)
I
ERROR CHECKING
620 to Computer
I
STX
CUA
X '09'
Message
ETX
LRC
,
i
EOT
In synchronous
data
communication, the
parity
bit
of each
data
byte
must
be such
that
odd
parity
over
the byte
results.
In asynchronous
data
communication, the
parity
bit
of each byte
must
be such
that
even
parity
over
the
seven
data
bits
and one
parity
bit
results.
The 620
inserts
correct
vertical
parity
in
all
transmitted.
characters
and
checks
vertical
parity
in
all
received
characters.
Receipt in a
message
sequence
from
the CPU
of a
character
whose
vertical
parity
is
incorrect
results
in
display of an
error
character
on the
screen.
In the
response
mode, detection
of
a
vertical
parity
error
in any
character
from
the
CPU
results
in
transmission
of
a
NAK
to the CPU
after
completion
of
the
transmission
from
the CPU.
The longitudinal redundancy
character
used
in the
response
modes
is
the
half-add
of
each
of
the
data
bits
and the
parity
bit
of
all
characters
(except the STX)
in
the
message
sequence. Since the
parity
bit
of the
LRC
is
the
half-add
of
the
parity
bits
of
the
previous
characters,
the LRC does not
necessarily
contain
correct
vertical
parity.
Detection of a
longitudinal redundancy
error
by
the
620
results
in
the
transmission
of a
NAK
to the CPU.
Also the CPU should send a
NAK
to the
620
if
such
an
error
is
detected
in
a 620
message
sequence
transmission.
12
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