Control Data 1700 User manual

CONTROL DATA
CORPORATION
CONTROL DATA®
1700 COMPUTER SYSTEM
1732-A/B MAGNETIC TAPE CONTROLLER
REFERENCE MANUAL

REVISION
A
(9-15-70)
Publication No.
60330800
© 1970
REVISION RECORD
DESCRIPTION
Manual released; this manual supersedes the 1732- A /B Magnetic Ta~e Controller section of the
obsolete CONTROL DATA® 1700 COMPUTER SYSTEM STANDARD PERIPHERAL REFERENCE
MANUAL, Pub. No. 60182700.
Rev. T of the obsolete manual.
The information contained herein is the same as that found in
Address comments concerning this
manual to:
by Control Data Corporation
Control Data Corporation
Technical Publications Department
4201 North Lexington Avenue
Arden Hills, Minnesota 55112
or use Comment Sheet in the back of
this manual.
Printed in the United States of America

PREFACE
This manual gives reference information for the CONTROL DATA® 1732-A/B Magnetic Tape
Controller which may be used in conjunction with the 1705 Interrupt Data Channel of the 1700
Computer. For reference information on 1700 Basic Peripheral Equipments (which attach
directly to the 1704 Basic Computer ) see the 1700 Computer System Reference Manual,
Pub. No. 60153100.
60330800 A
iii

Introduction
Functional Description
1
2
3
4
1
2
3
4
System Relationship
Magnetic Tape
Tape Format
Parity
Cyclic Redundancy Check (CRC)
Master Clear
Reply / Rej ect
File Protection
Program Protection
Typical Configurations
Tape Format
Physical Layout of Tape
File Protection Ring
Tape Format
1732 Operations
Motion Control
Director Status 1 Response Bits
60330800 A
CONTENTS
1
Programming
1
Summary of Programming
1
Information
3
Addresses
3
Operations
6
Status Response
6
Interrupts
6
Programming Example
6
Manual Operation
7
7
FIGURES
2
4
5
7
5
6
7
TABLES
4 5
8 6
9 7
10
Switches and Indicators
Operating Procedures
Format of Q Register
(A) for Control Function
(A) for Unit Select
Director Status 2 Response Bits
Controller Select Codes
Tape Unit Select Codes
8
8
10
11
16
18
18
21
21
24
8
9
9
10
11
14
v

INTRODUCTION
FUNCTIONAL
DESCRIPTION
System Relationship
60330800
1732-A/B MAGNETIC TAPE CONTROLLER
The CONTROL DATA ® 1732 Magnetic Tape Controller synchronizes data
transfer between a 1700 Computer System and up to eight 608 or 609 Tape
Transports. This section describes the physical system, the programming
information, and the operating procedures for the 1732 and 608/609.
As Figure 1 illustrates, the 1732 may be attached directly to the AQ Channel
or it may be attached to a 1706 or 1716 converter. The tape transports with
which the 1732 is associated are the 7-track 608 and 9-track 609. These
may be intermixed on the system as the user desires.
The equipment number switch, located on the controller, designates the con-
troller address (0 through F hexadecimal). Anyone of the eight tape trans-
ports attached to the controller may be selected.
Character-Assembly/Disassembly Operating Modes
The 1732 operates in either Character mode or Assembly/Disassembly
mode. In Character mode the 1732 sends data bits 0- 5 or 0-7 to the tape
transport (depending upon whether the tape unit is 7 or 9 track). The upper
8 or 10 bits are ignored by the controller. Likewise, when the computer
reads data from the tape via the 1732 in Character mode, each tape word is
sent to the computer in bit positions 0-5 (or 0-7); the remaining bits are
ignored by the computer.
However, in AID mode each computer word sent to the tape via the 1732 is
disassembled into two sections before being sent to the tape unit. If the
computer is sending data to a 7-track 608 tape unit, data bits 8-13 comprise
the first tape word and data bits 0-5 comprise the alternate tape word. Bits
6, 7,14 and 15 are ignored.
1

If the computer is sending data to a 9-track 609 tape unit, data bits 8-15
comprise the first tape word and data bits 0-7 comprise the alternate tape
word.
If the controller, operating in AID mode, reads an odd number of tape words,
the lower bits of the last assembled word will be filled with zeroes. The
FILL status bit will s~t to indicate that this portion of the assembled word is
not a tape word.
1705
OIR
STO
ACC
BUS
I
N
T
E
1704
R
1732
R
u
p
T
5
AO
CH
1705
OIR
STO
ACC
BUS
1706/
1716
I
N
T
E
1704
R
1732
R
u
P
T
5
AO
CH
Figure 1. Typical Configurations
2 60330800 A

Magnetic Tape
Tape Format
60330800 A
Magnetic tape provides a high-speed, nonvolatile storage medium. The tape
has a plastic base and is coated on one side with a magnetic oxide. Informa-
tion is recorded on this coating. Extreme care is taken to prevent error-
causing imperfections.
Information is read (detected) or written (stored) by passing the oxide side
of the tape over read/write heads. Information may be written on any or all
of the tape tracks. During a Read or Write operation, the tape pasces over
seven or nine evenly aligned heads; therefore, all bits of the tape word may
be simultaneously recorded, one bit on each track.
A non-return-to-zero (change-on-ones) recording scheme is used. In this
system, magnetic particles on the tape are aligned in either the positive or
negative direction. A binary "1" is recorded by reversing the alignment
(polarity); no polarity reversal indicates a "0". Thus, each track of the tape
is fully magnetized and the polarity is reversed as each" 1" bit is recorded.
Table 1 and Figure 2 describe the data format of magnetic tape. A line or
frame of tape data consists of a 6- bit or 8- bit tape word and a parity bit.
In a 608, tracks 0 through 5 contain the data bits and track 6 holds the parity
bit. In a 609, tracks 0 through 7 contain the data bits, and track 8 holds the
parity bit.
Density
The controller, when connected to the 608 tape transport, may be selected to
synchronize data at a rate of 200, 556 or 800 bits per inch. When the con-
troller is connected to a 609 tape, 800 bpi is the only possible density selec-
tion. The tape speed in both tape handlers is 37-1/2 inches per second.
Mode
The 608 tape transport records data in either of two modes: Binary mode,
which uses odd parity; or BCD mode. which uses even parity. Since there is
no BCD conversion in the 1732, the BCD "zero" character is illegal and
should not be used.
BCD can not be used with the 609 tape transport.
3

Tracks
Tape Speed
Density (bpi)
Parity
TABLE 1. TAPE FORMAT
seven
37 1/2 ips
200
556
800
608
Vertical Binary-odd
BCD-even
placed in seventh track
Longitudinal even parity check character
spaced 4 frames from last
data character.
Cyclic Redundancy none
Code Word
File Mark A BCD 178 six inches from
last record. The file mark is
followed by a longitudinal check
character of BCD 17
8,
Tape Mark none
Initial Gap 3.0 inches minimum for write
0.5 inches for read
Record Gap
BOO BPI -0.00125
556 BPI -O.OOIB
1 ,200 BPI -0.005
0.687 inches minimum
0.960 inches maximum
0.750 inches nominal
609
nine
same
800
odd - placed
in ninth track
even parity check
character spaced 4
frames from the CRC
code word.
spaced 4 frames from
last data character
none
A 238 6 inches from
the last record. It is
followed by an ident-
ical check character.
same
0.50
0.75
0.60
inches minimum
"
"
maximum
nominal
BCD BIT 608 BINARY
rPOSITION
(BIT P('SITION
,
1:::: ::: !
0.032 .l..lliD]1 I I II -L 0 04B
(READ) I (WR'TE)
,- t
TRACK
DETAIL
111111111111 4
111111111111 5
111111111111 •
111111111111 7
.,
p .,
5 :I
.,
7 ,
111111 11111 ~ ·1111 III 8
11111111 III ; jill "" A
11111111 III \ t"llill 8
11111111111 I "-.';.;.".;.;".;.;,,_<'-- ____ -'
NOTES:
~R~c:r.;;-f~~~:,: l ~ -1- - ~E:O~D~- - - - - - -
j kONGITUDINAL
CHECK C!-tAR GAP
200 BPI - 0.02
556 BPI - 0.0074
BOOBPI- 0.005
I. OXIDE SIDE UP ON DIAGRAM, RECORDING HEAD ON SAME SIDE AS OXIDE.
2. WRITE FREQUENCY 7.5 KC ::!: ,0/
0•
20.8'5 KC tl%. OR 30"'C :tlo/a.
3. AvERAGE STEADY STATE TAPE SPEED 37.5 ips.
Figure 2. Tape Format
4 60330800 A