Control Data 3228-A User manual
Reference/InstructionManual
CONTROL
DATA@
3228-A/3229-A
MAGNETIC
TAPE
CONTROLLER
60100300
REVISION
A
B
C
(4-12-65)
D
(6-7-65)
Pub.
No.
60100300
June,
1965
Record
of
Revisions
NOTES
Addition
of
2
Parts
Lists
as
Appendices
C
and
D.
Incorporation
of
Change
Order
893
O.
which
advanced
the
Product
Designation
to
3228/3229
-
A04.
This
manual
obsoletes
all
previous
editions.
Table
of
Contents
(iii),
1-1,
1-11
through
1-13,
11-31,
II
-
32,
II-
33,
II
-
35,
II
-
37,
II
-
39,
II
-
41,
II
-
42,
II
- 43,
11-45,
II-47,
11-49,
II-51,
II
- 53,
II-55,
11-
62,
111-4,
III-9,
A-11
and
A-13
revised.
Updated
Parts
List
(pages
C-1
through
C-6).
Address
comments
concerning
this
manual
to:
Control
Data
Corporation
Technical
Publications
Department
4201
North
Lexington
Avenue
St.
Paul,
Minnesota
55112
©
1965,
Control
Data
Corporation
Printed
in
the
United
States
of
America
or
use
Comment
Sheet
in
back
of
this
book.
CONTENTS
Part
I.
Description
and
Operation
Section
1.
Introduction
Section
2.
Description
Physical
Description
Functional
Description
Clear
Connect
Status
Select
Function
Codes
Format
Interrupt
Information
Transfer
Data
Conversions
Section
3.
Operation
Switches
and
Indicators
Equipment
Selection
Switch
Longitudinal
Parity
Write
Vertical
Parity
I-I
1
....
4
1-4
1-4
1-5
1-5
1-7
1-8
1-10
1-11
1-12
1-16
1-16
1-16
1-16
1-16
Interrupt
1-17
BCD
1-17
Part
II.
Theory
of
Operation
Section
1.
Connect
Section
2.
Function
Selection
Section
3.
Function
Operation
(Format)
Section
4.
Information
Transfer
II-I
II-5
II-I0
II-21
Register
Transfers
During
Write
II-21
Register
Transfers
During
Write
Reply
II-26
Register
Transfers
During
Read
II-26
iii
Write
Operation
Sequence
(First
Output
Word)
Write
Operation
Sequence
II-31
(N
ot
First
or
Last
Output
Word)
II
-31
Write
Operation
Sequence
(Last
Output
Word)
II-32
Write
Operation
Sequence
(Non-Stop)
II-32
Write
Operation
Sequence
(Write
Reply)
II-33
Read
Operation
Sequence
(First
Two
Frames)
II-41
Read
Operation
Sequence
(Not
First
Two
Frames)
II-42
Read
Operation
Termination
Sequence
(End
of
Record)
II-42
Read
Operation
Termination
Sequence
(Not
at
End
of
Record)
II-43
Reverse
Read
Operation
Sequence
II-44
Suppress
Assembly/Disassembly
Operation
Sequence
II-44
Section
5.
Function
Operation
Motion
Directives
Skip
Bad
Spot
Write
File
Mark
Search
Forward
to
File
Mark
II-53
II-53
II-53
Search
Backward
to
File
Mark
II-53
Backspace
II-53
Rewind
II-54
Rewind
Unload
II-54
Section
6.
Program
Conveniences
Interrupt
Function
Status
Lost
Data
Condition
During
Write
Lost
Data
During
Read
II-62
II-65
II-66
II-66
Rev.
C
Part
III.
Maintenance
Section
2.
Logic
Cabling
III
-1
Section
1.
Environmental
Care
III-l
Section
3.
General
Maintenance
Procedure
III
-10
Appendix
A.
Tape
Synchronizer
/
Controller
Glossary
Appendix
B.
3228/3229
Operation
in
a
3400
or
3600
System
Appendix
C.
3228/3229
Parts
List
FIGURES
Part
1.
Description
and
Operation
2-23
Write
Register
1-1
3228/3229
Control
Panel
1-2
(One
Channel)
II-25
1-2
3228/3229
Magnetic
Tape
2-24
BCD
Conversion
II-28
System
1-2
2-25
12-to-0
Conversion
II-29
Part
II.
Theory
of
Operation
2-26
Assembly
Control
II-30
2-1
Connect
FFs
II-2
2-27
Write
Timing
II-35
2-2
Connect
Operation
II-3
2-28
Flow
Chart:
Write
Prepara-
tion
and
Write
First
Data
2-3
Connect
Timing
II-4
Word
Operation
II-37
2-4
Function
Select
FFs
II-6
2-29
Flow
Chart:
Write
Termina-
2-5
Function
Reply
/
Reject
II-7
tion
and
Write
Nonstop
Oper-
ation
II-39
2-6
Function
Select
Timing
II-8
2-30
Read
Timing
II-45
2-7
Clear
and
Release
II-9
2-;:H
Flow
Chart:
Read
Prepara-
2-8
Parity
Mode
II-I0
tion
and
Read
First
Data
2-
9
Binary
Mode
Operation
II
-11
Word
Operation
II-47
2-10
Clear
Operation
II-12
2-32
Flow
Chart:
Read
Termina-
tion
(Not
End
of
Record)
and
2-11
Release
Operation
II-13
Read
Nonstop
Operation
II-49
2-12
Density
II-14
2-33
Flow
Chart:
Read
Termina-
2-13
200
BPI
Operation
II-15
tion
(End
of
Record)
and
Read
Nonstop
Operation
II-
51
2-14
556
BPI
Operation
II-16
2-34
Skip
Bad
Spot
II-
55
2-15
800
BPI
Operation
II-17
2-35
Write
File
Mark
II-56
2-16
Tape
Motion
Signals
II-18
2-36
Search
Forward
to
File
2-17
Reverse
Operation
II-19
Mark
II-57
2-18
Clear
Reverse
Operation
II-20
2-37
Search
Backward
to
File
2-19
Data
Transfer
II-22
Mark
II-58
2-20
Disassembly
Control
II-23
2-38
Backspace
II-59
2-21
BCD
Conversion
II-24
2-39
Rewind
II-60
2-22
0-to-12
Conversion
II-24
2-40
Rewind
Unload
II-61
iv
FIGURES
(Cont'd)
Part
II
(Cont'd)
2-43
Inte
rrupt
on
End
of
Oper-
2-41
Interrupt
Select
II-63
ation
II-64
2-42
Interrupt
on
Ready
II-64
2-44
Interrupt
on
Abnormal
End
of
Operation
II-65
TABLES
Part
1.
Description
and
Operation
3-2
Signal
and
Pin
Assignments:
1-1
Assembly/Disassembly
Byte
Input
Cable
1II-3
Order
1-15
3-3
Signal
Definitions
1II-4
1-2
Function
Codes
and
Status
3-4
Signal
and
Pin
Assignments:
Responses
1-17
Data
I/O
Cable
III-6
Part
II.
Theory
of
Operation
3-5
Signal
and
Pin
Assignments:
Control
I/O
Cable
1II-7
2-1
Connect
Sequence
II-I
3-6
Data
Channel
Signals
1II-8
2-2
Function
Codes
II-5
3-7
Critical
Delay
Table
III
-11
Part
III.
Maintenance
3-1
Signal
and
Pin
Assignments:
Output
Cable
III-
2
v
3228/3229
Magnetic
Tape
Controller
PART
I.
DESCRIPTION
AND
OPERATION
SECTION
1.
INTRODUCTION
The
CONTROL
DATA)~
3228/3229
Magnetic
Tape
Controllers
are
input/output
devices
for
a
Control
Data
3000
series
Computer
System
(Figure
1-
2).
Either
controller
can
be
connected
to
one
3000
series
12
-
bit
data
channel.
The
schem
e
of
selection
and
operation
follows
the
method
inherent
in
any
3000.
series
peripheral
equipm
ent.
The
controller
allows
the
data
channel
to
select
a
particular
tape
handler
and
modifies
and
synchronizes
data
flow.
The
controllers
may
use
all
603,
all
604,
all
606,
or
all
607
tape
handlers.
The
3228
may
use
up
to
four
tape
handlers,
the
3229
up
to
eight.
The
tape
handlers
are
selected
and
operated
by
the
exchange
of
requests
and
replies
typical
to
the
60X
tape
systems.
The
controller
can
read
or
write
on
one
tape
handler
at
a
time.
Search
and
rewind
functions
of
the
tape
handler
free
the
controller
or
the
data
channel
for
other
operations.
Operation
of
the
controller
using
603
or
606
tape
handlers
(as
opposed
to
the
higher
performance
604
or
607
tape
handlers)
is
a
programming
consideration.
The
603
and
604
tape
handlers
move
tape
at
75
ips,
the
606
and
607
at
150
ips.
In
this
manual,
any
time
a
delay
period
is
mentioned
by
itself,
it
is
common
to
either
tape
speed.
If
a
delay
period
is
mentioned,
followed
by
another
delay
period
in
parentheses,
the
first
delay
period
is
for
150
ips
and
the
second
for
75
ips.
Whenever
a
page
reference
in
this
manual
is
given
in
parentheses,
e.
g. :
(Page
6),
it
refers
to
a
page
in
the
3228/3229
Magnetic
Tape
Controller
Custom
er
Engineering
Diagrams
Manual
(Pub.
No.
60093700),
):<
Registered
trademark
of
Control
Data
Corporation.
I-I
Rev.
C
0507
~
0501
l
6
LONGITUDINAL
PARITY
0
0 0 0 0 0
7 6 5 4 3 2
0 0 0 0
BCD
INT
VERT
WRITE
PARI
TY
f t i i
0511
OSlO
0509 0508
Figure
1-1.
3228/3229
Control
Panel
h~~1
~
L-...J
~~
~
__
3_00_0
__
5_E_R_IE~S~,_12_-_B_IT
__
~CONTROLLER
DATA
CHANNEL
*
3228-4
TAPE
HANDLER MAXIMUM.
3229-
8
TAPE
HANDLER MAXIMUM.
603,604,606,
OR
607
TAPE HANDLERS
1
Figure
1-2.
3228/3229
Magnetic
Tape
System
1-
2
[IJ
t
EQUIPMENT
N
(O
-7)
*
3228
*
3229
SWITCH
Computer
-
Tape
Handler
operations
are
selected
by
computer
EF
codes
and
signals.
These
control
the
following
functions:
1)
Connect
(code
and
signal)
Data
Channel
Controller
Tape
Handler
2)
Status
(on
status
lines
after
connect)
3)
Function
-
Format
(code
and
signal)
Format
Release
Parity
Mode
Density
Clear
Reverse
Read
'-
Release
Same
(604/607
only)
Motion
Directives
Rewind
Rewind
Unload
Backspace
Search
Forward
to
File
Mark
Search
Backward
to
File
Mark
Write
File
Mark
Skip
Bad
Spot
Interrupt
Ready
and
Not
Busy
-
Release
Same
End
of
Operation
-
Release
Same
Abnormal
End
of
Operation
-
Release
Same
4)
Information
Transfer
Write
(signals)
Read
(signals)
5)
Assembly/Disassembly
or
Character
(signal)
1-3
SECTION
2.
DESCRIPTION
PHYSICAL
DESCRIPTION
The
3228/29
controllers
may
be
mounted
in
a
number
of
different
cabinets
and
configu-
rations.
The
installation
engineer
can
determine
the
accurate
physical
description
of
an
actual
installation
by
using
data
from
the
3200
Site
Preparation
Manual
(Pub.
No.
60090100).
Description
of
the
3228/29
control
panel
is
in
Section
3,
Operation.
FUNCTIONAL
DESCRIPTION
CLEAR
Prior
to
initial
use
of
the
tape
controller,
the
system
should
be
cleared.
There
are
five
possible
ways
of
clearing
the
controller:
1)
Clear
Channel
(100
J,Lsec)
This
instruction
clears
all
activity
in
the
data
channel
and
clears
the
tape
handler
connection.
2)
Clear
(2 J,Lsec)
This
instruction
clears
the
tape
handler
connection
but
the
controller
remains
"connected"
in
the
sense
that
Status
signals
are
still
available
for
the
data
channel.
3)
Release
This
instruction
clears
only
the
connection
for
a
connected
tape
handler
(not
relevant
in
a
3228/3229
-
used
for
compatibility).
The
latter
two
Function
instructions
(Clear
and
Release)
can
only
be
used
after
the
controller
is
connected
to
a
tape
handler.
4)
Power
On
MC
When
power
is
applied
to
the
3228/29,
all
tape
handlers
connected
are
cleared.
Logic
in
the
controller
is
also
cleared,
and
no
Status
signals
are
available
to
the
data
channel.
5)
External
MC
This
clears
all
tape
handlers
connected
and
clears
the
logic
in
the
controller.
No
Status
signals
are
available
to
the
data
channel
after
executing
this
operation.
Both
Master
Clear
operations
place
the
3228/29
in
binary
format.
I-4
CONNECT
The
computer
sends
a
12-
bit
Connect
code
over
the
data
channel
to
the
t~pe
controller.
A
manual
Equipment
Selection
switch
on
the
tape
controller
locks
out
all
Connect
codes
except
the
ones
having
the
correct
bit
combinations
in
bits
9,
10,
and
11.
These
bits
must
match
the
switch
setting
on
the
3228/29
or
the
processor
will
not
make
the
connec-
tion.
Bits
0, 1,
and
2
may
have
octal
values
of
0 - 7.
These
bits
determine
with
which
of
the
tape
handlers
the
3228/29
will
communicate.
Bits
3,
4,
5, 6, 7,
and
8
are
not
used.
If
none
of
the
controllers
or
any
other
equipments
physically
connected
to
the
processor
via
data
channels
have
the
proper
switch
setting,
or
a
parity
error
occurs
in
the
Connect
code,
an
Internal
Reject
is
generated
by
the
computer.
STATUS
After
the
desired
tape
handler
has
been
connected,
it
is
usually
necessary
to
check
the
status
of
the
handler
before
attempting
any
further
operations.
Ready
(XXXI)
A
Ready
indicator
on
the
tape
handler
lights
when
it
is
in
a
Ready
condition,
i.
e.
J
power
has
been
applied
and
the
tape
handler
is
in
Automatic
mode.
When
in
Automatic
mode,
the
tape
handler
is
controlled
by
the
tape
controller.
The
Ready
signal
is
not
present
when
the
tape
handler
is
manually
operated
from
its
control
panel.
Read/Write
Control
(and/
or)
Busy
(XXX2)
This
signal
is
present:
1)
If
the
tape
handler
is
Ready.
2)
During
and
for
5
ms
after
any
operation
requiring
tape
motion
(Read,
\Vrite,
etc.
).
3)
Whenever
the
data
channel
begins
executing
or
is
executing
a
Read/Write
in-
struction.
This
signal
will
not
be
present
if:
1)
The
tape
handler
is
not
Ready.
2)
The
channel
begins
executing
or
is
executing
a
Read/Write
instruction,
and/
or:
a.
Lost
Data
has
occurred
in
a
previous
operation.
b.
Interrupt
On
Abnormal
End
of
Operation
has
occurred
in
a
previous
oper-
ation
and
the
Interrupt
signal
is
still
present.
1-5
Write
Enable
(XXX4)
This
signal
is
present
only
when
the
file
protection
ring
is
on
the
tape
reel.
When
this
signal
is
absent,
it
is
impossible
to
write
on
tape,
although
information
may
be
read
from
the
tape.
File
Mark
(XX1X)
This
signal
is
present
when
the
tape
handler
has
searched
for
and
located
an
End
of
File
Mark.
It
is
also
present
immediately
after
writing
an
End
of
File
Mark.
This
signal
drops
when:
(1)
reading/writing
begins
on
a
new
record,
or
(2) a
Backspace,
Search
End
of
File
Mark
Forward,
or
Search
End
of
File
Mark
Backward
operation
is
initiated.
Load
Point
(XX2X)
This
signal
is
present
when
the
tape
is
at
Load.
Point.
The
signal
drops
when
tape
motion
begins.
End
of
Tape
(XX4X)
This
signal
is
present
when
the
End
of
Tape
marker
is
detected.
The
signal
drops
when
tape
has
been
rewound
past
the
End
of
Tape
marker.
Density
(X1XX)
See
table
1-
2
Density
(X2XX)
See
table
1-
2
Lost
Data
(X4XX)
This
signal
appears
during
a
Write
operation
(Write
signal
present)
if
the
tape
control-
ler
is
ready
to
accept
information
but
the
Data
signal
from
the
data
channel
is
absent.
When
the
Lost
Data
signal
appears
during
a
Write
operation,
tape
motion
stops.
Further
Write
operations
are
impossible
until
the
Lost
Data
signal
is
cleared
with
a
new
Function
or
Connect
code.
The
Lost
Data
signal
also
appears
during
a
Read
operation
(Read
signal
present)
when
the
tape
controller
has
data
ready
for
output,
but
the
Data
signal
from
the
data
channel
is
absent.
1-6
If
the
Lost
Data
signal
appears
during
a
Read
operation,
reading
continues
until
the
end
of
the
record.
Further
Read
operations
are
impossible
until
the
Lost
Data
signal
is
cleared
with
a
new
Function
or
Connect
code.
(Any
legal
Function
code
listed
in
table
1-2
will
clear
the
Lost
Data
signal.
)
The
Lost
Data
signal
is
meaningless
when
the
tape
controller
is
attached
to
a
160/160-A
via
a 3681
adapter.
However,
this
signal
must
be
cleared
if
Read/Write
operations
are
to
continue.
End
of
Operation
(lXXX)
This
signal
indicates
that
an
operation
is
completely
finished.
Parity
Error
(2XXX)
This
signal
indicates
that
a
parity
error
has
occurred
during
a
Read/Write
operation.
This
signal
drops
when
reading
begins
on
a
new
record.
A
Clear
Channel
instruction,
External
Master
Clear
or
a
Power
On
Master
Clear
causes
this
signal
to
drop.
The
Parity
Error
signal
also
appears
when
an
End
of
File
Mark
is
sritten
or
read
in
Binary
mode.
SELECT
FUNCTION
CODES
The
following
information
refers
to
the
Function
codes
used
with
the
Function
instruc-
tion,
i.
e.,
the
lower
12
bits
which
specify
the
operation.
An
octal
0
or
4
in
bits
3, 4,
and
5
of
the
Function
code
indicates
format,
an
octal
1
in
bits
3, 4,
and
5
indicates
tape
motion,
and
an
octal
2
in
bits
3, 4,
and
5
indicates
Interrupt.
The
proper
tape
handler
must
be
connected
before
a
Function
instruction
can
be
issued.
If
an
error
occurs
in
the
Function
code
(assuming
the
proper
unit
is
connected),
a
Parity
Error
signal
appears
on
a
transmission
parity
error
line
and
the
computer
issues
an
Internal
Reject
after
100
usec.
Once
a
function
(Backspace,
Rewind,
etc.)
is
initiated
un
a
tape
handler
on
a
given
channel,
it
is
possible
to
connect
another
tape
handler
on
the
same
channel,
perform
some
operation
on
the
second
tape
handler,
and
reconnect
the
first
tape
handler
when
the
operation
on
the
second
handler
terminates.
I-7
Rev.
C
FORMAT
Release
(0000)
A
Release
code
clears
the
existing
unit
connection
for
a
tape
handler.
Binary
(0001)
A
0001
code
allows
all
information
to
be
written
or
read
in
binary
notation.
A
parity
generator
makes
the
total
number
of
1
bits
odd
in
the
transverse
(vertical)
direction
on
a
total
of
seven
separate
tracks
on
tape.
The
End
of
Record
check
character
makes
the
longitudinal
number
of
bits
in
each
of
the
seven
tracks
even.
During
Read
or
Write
operations,
a
constant
transverse
parity
check
is
made.
A
parity
error
is
indicated
on
a
status
line
if
a
vertical
parity
error
is
detected.
Coded
(0002)
A
0002
code
allows
all
information
to
be
written
or
read
in
binary
coded
decimal
(BCD)
notation.
A
parity
generator
makes
the
total
number
of
1
bits
even
in
the
transverse
(vertical)
direction
on
the
seven
tracks
on
tape.
Constant
parity
checks
during
Read/
Write
operations
are
performed
in
the
same
manner
as
in
binary
format.
556
BPI
Density
(0003)
200
BPI
Density
(0004)
A
0003/0004
code
permits
all
information
to
be
written
onto
or
read
from
the
tape
at
556/200
density.
Clear
(0005)
A
0005
code
clears
all
existing
tape
handler
connections.
It
is
desirable
to
issue
this
code
when
the
channel
has
completed
all
operations
on
one
or
more
tape
handlers.
800
BPI
Density
(0006)
A
0006
code
permits
all
information
to
be
written
or
read
onto
or
from
the
tape
at
800
density.
(On
604/607
Tape
Handlers
only.
)
Set
Reverse
Read
(0041)
This
code
is
used
for
a
Revers
e
Read
operation.
(See
Revers
e
Read
section.)
(On
604/
607
Tape
Handlers
only.
)
Rev.
C
1-8
Clear
Reverse
Read
(0040)
This
code
clears
the
condition
established
by
the
0041
Format
code.
All
of
the
Format
codes
(0000-0006,
0041,
0040)
result
in
a
Reject
if
attempted
when
the
Read/Write
control
is
busy.
Rewind
(0010)
A
0010
code
rewinds
tape
at
high
speed
(225-400
inches/second)
to
the
Load
Point.
Any
further
Rewind
instructions
will
initiate
an
imm
ediate
Reply.
A
Load
Point
signal
appears
on
a
status
line
when
the
operation
is
complete.
Rewind
Unload
(0011)
A 0011
code
rewinds
tape
at
high
speed
until
all
the
tape
is
on
the
supply
reel.
All
further
operations
on
this
tape
are
locked
out
until
the
tape
has
been
reloaded
manually.
Backspace
(0012)
A
0012
code
backspaces
tape
one
record
length.
If
the
Load
Point
occurs
than
at
the
beginning
of
the
tape,
this
code
will
backspace
tape
from
Load
Point
to
one
record
length
behind
the
Load
Point.
Search
End
of
File
Mark
Forward
(0013)
Search
End
of
File
Mark
Backward
(0014)
A
0013/0014
code
searches
forward/reverse
until
an
End
of
File
:Mark
is
detected.
A
File
Mark
signal
appears
on
a
status
line
when
the
operation
is
complete.
If
no
file
marks
are
detected,
tape
motion
continues
until
tape
is
completely
off
the
supply
reel.
Write
End
of
File
Mark
(0015)
A
0015
code
writes
178
as
an
End
of
File
Mark
(even
transverse
parity)
in
both
binary
and
BCD
format.
Writing
an
End
of
File
Mark
does
not
change
the
current
format.
Skip
Bad
Spot
(0016)
A
0016
code
moves
and
erases
tape
6
inches
in
a
forward
direction.
If
Interrupt
On
End
of
Operation
is
selected,
Interrupt
will
occur
when
the
Skip
Bad
Spot
operation
is
complete.
NOTE
Codes
0010-0016
result
in
a
Reject
if
attempted
when
the
Read/Write
control
is
busy.
I-9
Rev.
C
INTERRUPT
All
desired
Interrupt
instructions
must
come
before
a
Read
or
Write
operation,
but
can
occur
during
any
other
operation.
The
Equipment
Selection
switch
determines
which
line
the
Interrupt
signal
is
transmitted
on.
For
example}
if
the
Equipment
Selection
switch
is
set
to
5,
any
Interrupts
coming
from
the
controller
will
be
transmitted
on
interrupt
line
5.
Any
new
Interrupt
instruction
clears
the
existing
Interrupt
signal.
This
signal
is
also
cleared
by
releasing
all
three
possible
Interrupts
or
doing
a
Master
Clear.
Interrupt
on
Ready
and
Not
Busy
(0020)
Release
Interrupt
ob.
Ready
and
Not
Busy
(0021)
The
0020
code
allows
a
tape
unit
to
send
an
Interrupt
signal
out
on
the
channel
when
this
tape
handler
is
in
a
Ready
and
Not
Busy
condition,
i.
e.,
when
power
is
applied,
the
unit
is
in
Automatic
mode,
and
all
tape
motion
has
ceased.
Release
Interrupt
on
Ready
and
Not
Busy
code
0021
clears
this
condition.
Interrupt
on
End
of
Operation
(0022)
Release
Interrupt
on
End
of
Operation
(0023)
A
0022
code
allows
a
tape
handler
to
send
an
Interrupt
signal
out
on
the
channel
after:
1)
2)
A
File
Mark
has
been
located
in
a
Search
File
Mark
Forward
or
Backward
operation
3)
Load
Point
has
been
detected
during
a
Rewind
operation,
or
4)
A
Skip
Bad
Spot
operation
has
been
completed.
Release
Interrupt
on
End
of
Operation
code
0023
clears
this
condition.
Interrupt
on
Abnormal
End
of
Operation
(0024)
Release
Interrupt
on
Abnormal
End
of
Operation
(0025)
A
0024
code
allows
a
tape
unit
to
send
an
Interrupt
signal
out
on
a
channel
after
an
ab-
normal
operation
occurs.
The
abnormal
operations
are:
End
of
Tape,
File
Mark,
Load
Point,
Transverse
Parity
Error,
Lost
Data,
and
Connected
Tape
Handler
Becoming
Not
Ready.
In
all
but
the
last
case,
the
Interrupt
occurs
when
one
or
more
of
these
con-
ditions
is
encountered
and
an
End
of
Record
check
character
is
written
or
read
by
the
Rev.
C
1-10
tape
unit.
In
the
case
of
Interrupt
on
Connected
Tape
Handler
Becoming
Not
Ready,
Interrupt
occurs
immediately
when
the
handler
goes
from
a
Ready
to
a
Not
Ready
condition
(e.
g.,
if
someone
were
to
turn
off
the
power
on
the
tape
unit).
Interrupt
on
Connected
Tape
Handler
Becoming
Not
Ready
will
not
occur:
(1)
during
a
Connect
oper-
ation
or
(2)
when
a
0000
Function
instruction
(Release
Connected
Unit)
is
being
executed.
A
new
Read/Write
operation
cannot
start
until
the
Interrupt
signal
is
cleared
by
one
of
the
methods
mentioned
previously
in
this
chapter
under
the
Interrupt
section.
Release
Interrupt
on
Abnormal
End
of
Operation
code
0025
clears
this
condition.
The
processor
will
enter
an
Interrupt
routine
and
process
the
Interrupt.
A
Stop
Channel
Activity
instruction
(in
the
processor
Interrupt
routine)
will
terminate
data
channel
activity
and
store
the
present
word
count,
etc.
When
the
Interrupt
signal
is
cleared
(in
the
processor
Interrupt
routine),
reading
may
be
initiated
by
a
new
Read
instruction.
The
processor
will
enter
an
Interrupt
routine
and
process
the
Interrupt.
When
the
Interrupt
signal
is
cleared
(in
the
processor
Interrupt
routine),
writing
may
be
initiated
by
a
new
Write
instruction.
INFORMATION
TRANSFER
Write
Mter
the
tape
handler
has
been
connected
and
format
chosen,
the
programmer
should
check
status
for
a
Write
Enable
(bit
2
in
the
Status
Reply
code).
If
this
signal
is
not
present,
the
protective
ring
is
probably
missing
from
the
tape
reel.
It
is
possible
to
write
on
the
tape
only
when
this
condition
has
been
corrected.
(If
the
Write
Enable
is
not
present,
the
data
channel
hangs
up.)
If
the
Write
Enable
is
present,
accompanied
by
the
Ready
signal,
the
Write
operation
may
begin.
Read
In
a
Read
operation,
the
order
of
events
is
similar
to
the
Write
operation.
After
con-
necting,
checking
status,
and
choosing
the
proper
format,
the
Read
operation
begins.
It
is
not
necessary
to
check
for
a
Write
Enable,
since
Read
operations
from
the
tape
are
possible
when
the
protective
ring
is
not
present
on
the
tape
reel.
During
Read
and
Write
operations,
the
programmer
may
choose
to
check
status
period-
ically.
He
may
also
program
one
or
more
Interrupts
to
let
the
computer
know
when
1-11
Rev.
C
the
present
operation
is
complete.
Reverse
Read
(On
604/607
Tape
Handlers
Only)
The
322X
can
read
information
in
a
reverse
direction
from
tape.
Six-bit
frames
are
read
from
tape
and
assembled
into
12-bit
bytes
and
sent
to
the
data
channel.
When
a
word
is
read
in
a
reverse
direction
from
tape
and
entered
into
storage,
it
is
identical
to
the
word
which
was
initially
written
on
the
tape
from
storage.
There
is
no
change
made
in
the
final
order
of
the
bits
during
a
Reverse
Read
operation.
To
initiate
a
Reverse
Read
operation
(assuming
format
has
already
been
selected
and
all
tape
motion
has
stopped),
a
322X
controller
must
first
receive
the
Function
code
0041
(Reverse).
When
the
Read
instruction
is
executed
in
the
processor,
the
Reverse
Read
operation
will
begin.
A
Reverse
Assembly
signal
will
be
sent
to
the
data
channel
from
the
322X
to
indicate
that
the
12-bit
bytes
should
be
assembled
in
reverse
order.
Transverse
and
longitudinal
parity
checking
occurs
as
in
a
normal
Read
operation
with
one
exception:
if
the
first
frame
read
is
a
record
check
character,
no
vertical
parity
check
is
made
on
that
character.
Vertical
parity
checking
is
performed
on
all
remaining
frames.
If
C\.
Reverse
Read
is
attenlpted
from
Load
Point,
The
Read
operation
will
halt
indefinitely.
Parity
errors
and
Interrupts
may
be
handled
as
if
the
operation
were
a
Normal
Read.
An
End
of
Record
signal
is
returned
to
the
data
channel
~hen
a
record
gap
is
reached.
If
a
Backspace
function
is
selected
during
the
time
a
Reverse
Read
format
is
selected,
the
tape
will
"backspace"
forward.
The
Function
code
0042
(Clear
Reverse)
should
be
issued
when
the
Reverse
Read
oper-
ation
terminates.
DA
T A
CONVERSIONS
Transmission
Parity
All
information
transfer
between
the
data
channel
and
the
controller
uses
12
bits
of
data
and
1
parity
bit
(odd
parity).
The
controller
checks
the
accuracy
of
the
parity
bit
during
a
Write
operation
and
generates
the
bit
during
a
Read
operation.
Rev.
C
1-12
Illegal
BCD
The
tape
handler
generates
a
sprocket
pulse
whenever
it
senses
a
bit
in
a
frame
on
the
tape.
Therefore,
if
a
6-bit
data
character
of
all
zeroes
is
written
in
BCD
mode,
the
tape
handler
will
not
recognize
the
frame
and
an
error
would
occur.
To
prevent
this,
the
controller
automatically
converts
a
character
of
all
zeroes
to
128
when
writing
and
128
to
all
zeroes
when
reading.
This
makes
128
BCD
an
illegal
number
in
relation
to
the
computer.
Assembly
/
Disassembly
Example
I
in
table
1-1
shows
the
order
in
which
the
two
characters
in
each
data
channel
word
are
written
on
tape.
Example
IV
shows
the
order
in
which
data
on
tape
is
assem-
bled
to
the
data
channel.
Example
V
shows
the
assembly
during
a
Reverse
Read.
Suppress
Assembly/Disassembly
If
the
Suppress
Assembly/Disassembly
signal
is
sent
to
the
controller
during
a
Write
operation,
bits
6
through
11
of
the
Data
Channel
word
are
discarded
and
only
bits
0
through
5
are
written
on
the
tape
(table
1-1,
examples
II
and
II!).
If
the
signal
is
sent
to
the
controller
during
a
Read
operation
(forward
or
reverse),
bits
6
through
11
of
the
Data
Channel
input
word
are
packed
with
zeroes
(examples
VI,
VII,
and
VIII).
Programlning
Considerations:
1)
If
data
is
to
be
assembled
from
a
tape
that
was
recorded
in
Suppress
Assembly/
Disassembly
mode,
assembly
difficulties
may
be
encountered.
The
problem
is
that
in
Suppress
Assembly/Disassembly
mode,
an
odd
number
of
frames
may
be
written
on
the
tape.
If
this
occurs,
and
the
tape
is
read
forward,
the
controller
will
automatically
fill
in
bits
6
through
11
of
the
last
input
word
with
zeroes.
If
an
odd
number
of
frames
are
written,
and
a
Reverse
Read
is
attempted,
the
inverted
assembly
will
be
one
frame
out
of
order
and
bits
0
through
5
of
the
last
Data
Channel
word
will
be
filled
in
with
zeroes
(table
1-1,
example
IX).
2)
If
a
Reverse
Read
is
attempted
in
Suppress
Assembly
/
Disassembly
mode,
the
check
character
may
be
read
to
the
Data
Channel
as
the
last
frame
(first
Data
Channel
character).
If
no
check
character
exists
(check
character
=
zero
because
of
an
even
number
of
bits
in
each
tape
channel),
the
last
frame
will
be
read
as
the
first
Data
Channel
character
(table
1-1,
examples
VII
and
VII!).
I-13
Rev.
C
This manual suits for next models
1
Table of contents
Other Control Data Controllers manuals
