-o DIRECT DATA
o
I
,,-
...i
- TPS
7094
DISC7040 7288
-... ~
"II
ca·
e;
, ,
I
-" "
,/ , / ,/ ,/"
) / ,/ ,/ ,/SWITCH COMM
... ,/
BOX CENTER
/
"
,/,/ ... ,/
I
,/ ... ,/
r--'---, ( --'1
r o-I I I I
I 7094 I I DISC I 7040 7288
I I
L J
I I
L. _ _ _ ... ... ~- ...
, ,
CONTROL
I I
DPCC ANALYSIS DSIF COMM
CENTER CENTER
PLOTTER CONTROL
PRINTER
CARD
READER
SYSTEM 01 RECTORY 7040 OPERATING SYSTEM 7040 INITIALIZATION PROGRAM 70~~4 INITIALIZATION PROGRAM
7094 EDITOR PROGRAM 7094 Dlt,GNOSTICS PROGRAM
RAW- DATA STORAGE
M ASTER DATA TABl.E ALl. RAW AND REDUCED DATA
~. I
p
PLANETARY EPHEMERIS FORMATTED PRINT OUTPUT
FORMATTED PLOT OUTPUT TELETYPE OUTPUT 7094 USER PROGRAMS'
USER PROGRAM SAVE
Figure 3. DISC FILE loA YOUT
SYSTEM STORAGE
DATA STORAGE
7094 USER
PROGRAM STORAGE
The IBM 7094 computer, under control of an executive monitor, will perform the computation for orbit determination, science analysis, guidance analysis, etc. The 7094 will return its output to disc so that the 7040 may distribute it to the appro-priate area. The 7094 will also write output on magnetic tape for off line tabulation and plotting using IBM 1401 systems and a G.D.E. 4020 micro-film printer plotter.
The remainder of this paper will emphasize the function of the disc file system, the disc control programming system, and the layout of the disc file storage. A brief description of the general programming system will be included.
FUNCTION AND ORGANIZATION OF DISC FILE SYSTEM either the on line 7040 or the 7094 under program control, and capable of switching between 7040's under manual control. The 1301 units are stand-ard single arm units. Consideration was given for a special order for dual arms but a simulation verified that this would be unnecessary for our problem. For the purpose of this paper we will include a direct data connection between the 7904 on the 7040 and a 7607 data channel on the 7094 as part of the disc system.
The disc file system has six functions: storage of raw telemetry and tracking data for 7094 proc-essing; storage of 7094 outputs for distribution by the 7040; scratch storage for 7094 processing;
7040 and 7094 program storage; lunar and plane-tary ephemerides storage; and storage of the disc file directory. The disc storage is capable of stor-ing all data durstor-ing a sstor-ingle trackstor-ing station pass for missions in the planning stage. The direct data connection is used to transmit control infor-mation between computers, such as card images, 7040 priority request for disc access, priority con-trol information for the 7094, etc.
The disc storage is organized in different ways, depending on how the data are to be accessed.
Figure 3 shows the types of data kept on disc.
1. The Master Data Table (MDT) contains all the raw data measurements that have come in-to the system, sorted inin-to files by type of data.
The MDT consists of many separate data files.
Each of the data files represents a unique type of
raw data. These data files contain the raw measurements paired with a time value. Asso-ciated with each of these individual data files is a directory track. This directory track allows the computers to access any specified time interval of data for any specified data type.
2. The Raw Data Files contain the raw data analYSis programs. Each analysis program will have available a fixed number of blocks. These blocks will be numbered in sequential fashion.
The 7094 program reads and writes scratch disc by referencing the desired block number.
4. Formatted 7094 Output consists of the fully formatted plots, prints, and teletype outputs which the 7094 generates and stores on disc for 7040 output processing. These outputs are identified hy symbolic names and the 7040 is notified of their availability on disc. Depending upon pre-vious requests from the remote areas and on initialization parameters, the 7040 will perform various functions upon indication that 7094 out-put is on disc, which include notification to remote areas of display availability, queuing up of dis-play on various output devices, requesting verifi-cation for teletype transmission to the DSIF, etc.
There are in addition to these types of disc storage several types which represent straight-forward reading and writing of absolute files. The Operating System, Initialization Programs, and Editor represent the programs necessary to initial-ize the system, run the system, and restart the system. The User Programs are the various anal-ysis programs which operate under the system.
-c Vi n
3:
o
c c:
m
r-l>
'"
'"
Q z 3: m Z -t
,...--"""'4 1301 DISC FILE --~ 1301 DISC FILE
MODULE 0 o SYSTEM DIRECTORY
(I)
o MASTER DATA TABLE (175)
o 7040 SYSTEM (3)
o 7094 USER PROGRAMS (71)
MODULE I
o PLANETARY EPHEMERIS (250)
MODULE 2 o SYSTEM DICTIONARY
(I)
o MASTER DATA TABLE (175)
o 7040 SYSTEM (3)
o 7094 USER PROGRAMS (71)
MODULE ASSIGNMENT MADE ON BASIS OF:
o OPTIMUM DUPLICATION FOR BACKUP
o MAXIMUM RECOVERY CAPABILITY
MODULE 3 o RAW DATA TABLE
(10)
o 7094 PRINT OUTPUT (50) o 7094 PLOT OUTPUT
~ (50)
o 7094 TELETYPE OUTPUT (4)
o 7094 USER PROGRAM SAVE (65)
o 7094 USER PROGRAM TEMPORARY (65)
o 7040 INITIALIZATION PROGRAM (3) o 7094 INITIALIZATION
PROGRAM (3)
This scheme allows operations to continue if any disc or any module goes out. The operating sys-tem can run on two modules since we can stop duplexing data and we can go to tape for the Planetary Ephemeris.
In addition to duplexing, certain items are write checked or not depending upon the degree of reliability required. The necessity for check sum-ming will be determined after the discs have been in use long enough to truly evaluate their reli-ability. This feature will not be used in the initial operations.
The entire disc will be formatted with two 200-word records per track. This layout was dictated by the overall computer programming system.
Core space limitations restrict buffers in the 7040 to half track length. Since it is necessary to access successive records, a dummy space is left at the end of each record, in order that successive rec-ords can be accessed without waiting full disc revolution.
The disc directory was mentioned above. The actual disc access consists of a dictionary-directory system for the master data table. The dictionary is in core and provides the disc programs with the address of a particular directory. This directory record is then brought in to core. The disc pro-gram will then use this directory to locate a par-ticular data type for a parpar-ticular time period.
Since both computers access the same data, it is obvious that the dictionaries must be updated between computers. This is accomplished by use of the direct data connection which is independent of the disc files and allows transfer of information at a 62.5 kc word rate.
The 7040 system must be able to achieve im-mediate access to disc in order to service the high speed input buffers without loss of data. In case the 7094 has the disc when a high priority require-ment exists in the 7040, the 7040 uses the direct data connection to interrupt the 7094 and gain control of the disc. The maximum time delay for the 7040 to achieve control of the disc using this method is 50 microseconds plus the time to com-plete reading the current record, which is a maxi-mum time of 17 milliseconds.
PROGRAMMING SYSTEM
The overall programming system (Figure 5) logically consists of three different subsystems.
Each system operates asynchronously but must be cognizant of the status of the other subsystems.
Mutual control between subsystems is required.
The three subsystems are: the 7040 system, 7094 system, and the data control system which oper-ates in both the 7040 and the 7094 and is respon-sible for sequencing and issuing all disc file transactions and all direct data communications.
The 7040 and 7094 systems both have timesharing schemes; however, these schemes are completely different due to the difference in the functions performed by the two computers.
7040 system communications from the remote consoles. The 7040 can also convert data to engineering units and perform out of tolerance alarm monitoring on the telemetry data. The 7040 must be able to perform acquisition and monitoring on two mis-sions in parallel. Figure 6 is a generalized flow diagram of the 7040 system.
The basic structure of the 7040 includes the following types of routines:
1. Trap processors
The function of the trap processor is to process the data channel traps and move data from the trap buffer to a line processor buffer and to a tape output buffer. Trap processors are further divided into input trap processors servicing the input subchannels on the 7288, output trap processors servicing the output subchannels, a tape trap processor, and a disc trap processor.
2. Input processors
Input processors are controlled by the priority control program, PRIO, and are the ordinary processors which perform data identification and :separation of teletype data, phone line, microwave line data, card readers, and console inputs. These processors are responsible for operations on data stored in the line processor buffers by the trap processors. These routines also decode requests from the consoles, convert data to engineering units, perform the alarm monitoring and transfer data to sort buffers and to the plot and print huffer pool. The sort routine initiates requests to the disc control program when sort buffers are full and are written onto disc.
3. Output processors
These ordinary processors control the display of information in the analysis centers and the
dis-(Continued on page 107)
7040 SYSTEM OSI!'"
I. CONTROL ROUTINES
SITES ~ :.
•
:~ o. PRIORITY SEQUENCERI
~:~;;:- b. DISC CONTROL..,
c. DOC CONTROLii· C i
I
2. INPUT TRAP ROUTINESI
!" 7288 ~~ ': 3. IN PUT PROCE SSORS
~!i= o· REAL TIME DATA
~~f;'
USER REQUESTS
en 7:': b.
..,
COMMUNICATION CARD INPUT0
-
c...,
CHANNEL." 4 . OUTPUT PROCESSORS
'"
Q. SORTING0 (i) b. PLOTTING
'"
c. PRINTINGl> d. TELETYPE OUTPUT
~ e. TAPE OUTPUT
3:
t
f. ALARM COMPUTATIONSZ
9. ENG. UNITS CONVERSION(i) USER
5. OUTPUT TRAP ROUTINES
en AREAS
-< 6. SPECIAL PURPOSE ROUTINES
en -t o. ACCOUNTING
m ~ b. RECOVERY
c. DIAGNOSTICS j
7. AUXILIARY ROUTINES if o. INITIALIZATION
!
b. SIMULATION-I
DISC FILE
:\ ~ USER PROGRAMS
r
~.
. . --_~J7040-7094 !l SYSTEM
t