ATOMIC ENERGY R S 5
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1. Octobre 1979 AECL 658 ATOMIC ENERGY OF CANADA LIMITED THE DYNAMIC ANALYSTS FACILITY AT THE CHALK RIVER NUCLEAR LABORATORIES by D S Argue and W T Howatt ABSTRACT The Dynamic Analysis Facility at the Chalk River Nuclear Laboratories CRNL of Atomic Energy of Canada Limited AECL comprises a Hybrid Computer consisting of two Applied Dynamic International AD FIVE analog computers and a Digital Equipment Corporation DEC PDP 11 55 digital computer and a Program Development System based on a DEC PDP 11 45 digital computer This report describes the functions of the various hard ware components of the Dynamic Analysis Facility and the interactions between them A brief description of the software available to the user is also given Chalk River Nuclear Laboratories Chalk River Ontario 140 October 1979 AECL 6581 4 TABLE OF CONTENTS LIST OF FIGURES 1 INTRODUCTION ANALOG COMPUTER HARDWARE The AD FIVE Mainframe 1 Logic Components 2 Analog Components Data Output Devices 2 1 Oscilloscopes 2 2 Strip Chart Recorders 2 3 X Y Recorders N N N N WN ND N N N N PEP IR ES COMMUNICATION BETWEEN ANALOG AND DIGITAL COMPUTERS 3 1 The Renote Interface 3 2 The Hybrid Interface 3 3 Analog to Digital Converters 3 4 Digital to Analog Converters DIGITAL HARDWARE Central Processors The PDP 11 45 and PDP 11 55 Mainframes Real Time Clocks Multi Device Bulk Storage Bootstrap Loaders F2. Cleveland Ohio 1969 Mark 200 Recorder 1707 Series Manual Manual part number 801707 120 Gould Incorporated Brush Instruments Division Cleveland Ohio 1972 D C Premplifier Model 13 4215 32 Manual part number 13 804215 32 Gould Incorporated Instrument Systems Division Cleveland Ohio 1972 High Gain D C Preamplifiers Model 13 4215 02 and 13 4215 12 Manual part number 13 804215 02 Gould Incorporated Brush Instruments Division Cleveland Ohio 1970 Series 2000 Omnigraphic X Y Recorder Instruction Manual Houston Instrument Division of Bausch and Lomb Bellaire Texas System 511 Hybrid User s Manual Applied Dynamics AD Five Reference Manual Volume 2 Applied Dynamics Ann Arbor Michigan 15 16 17 18 19 20 21 22 23 24 25 53 Datawest Model 531165 Data Acquisition System Volume I and II Datawest Corporation Scottsdale Arizona C B Lawrence Function Generation for the Dynamic Analysis Facility unpublished Atomic Energy of Canada Limited report RNL 1693 Chalk River 1977 October 11 Processor Handbook 1978 79 Digital Equipment Corporation Maynard Massachusetts PDP ll Peripherals Handbook 1976 Digital Equipment Corporation Maynard Massachusetts M9301 Bootstrap Terminator Module Maintenance and Operator s Manual EK M9301 TM 001 Digital Equipment Corporation Maynard Massachusetts 1977 June BM792 Rea
3. the RIP performs either an internal function such as clearing one of its registers or establishes two way communication with the analog computer via the hybrid interface The RIF also contains the hardware necessary for implementing Direct Memory Access DMA communication between the digital and analog computers The only devices which may receive DMA data from the digital computer memory are the digital to analog converters and the digital coefficient units The Datawest analog to digital converter 15 is connected directly to the UNIBUS and therefore does not communicate via the RIF 19 Hardware necessary for handling interrupts generated by the analog computer is located in the RIF There are 15 possible interrupts of which 9 are triggered from the patch board by user programs The remainder are internally generated to inform communication software of errors or instruc tion completion The RIF can generate only one interrupt vector for the PDP 11 computer Since there are 15 possible interrupts an index word is available from a register in the RIF This word may be examined to determine which interrupt is currently pending Priority arbitration hardware in the RIF always presents first the pending interrupt with the highest priority Interrupt signals are brought directly to the RIF from the analog computer and are not subject to any RIF HIF communications protocol 3 2 The Hybrid Interface The Hybrid Interface is lo
4. One of the features of analog computation is the rela tive ease with which data may be displayed in graphic form Since the variables are already represented by voltages they may be directly applied to any device which records or displays voltage as a function of time or any other variable Common devices used are strip chart recorders X Y recorders and cathode ray oscilloscopes Each analog console has one of each 12 of the above instruments While the oscilloscope and X Y recorder are mounted in the display rack associated with each analog console see Figure 4 the strip chart recorders are free standing units which may be wheeled to either console The two display racks have 10 inter connecting trunks Also 10 of the AD FIVE analog trunks are brought out to each console s display rack so easy access to the rack is available from the patchboard The two strip chart recorders have 12 dedicated input lines while the X Y recorder and oscilloscope have 2 and 6 respectively All of these lines are terminated on the patchboard 2 2 1 Oscilloscopes Each AD FIVE analog console has in its associated dis play rack one Tektronix type R7613 variable persistence oscil loscope 3 The oscilloscope mainframe is capable of accepting any Tektronix 7000 series plug in unit The oscilloscope is used for displaying the analog problem solutions and also for debugging both the analog and logic sections of the programs The variable p
5. and indicator lamps are located to the left of the patchboard above the operator control panel The logic components are not address able by the AD FIVE addressing system but lamps indicate the output logic states An addressing capability is required in hybrid programs so a method has been provided to allow the digital computer to read the states of up to 16 logic signals This is accomplished with a 16 bit digital sense register Conversely the digital computer may write up to 16 bits of data to the logic program via the digital control register Both of these registers are terminated in the logic area of the patchboard Access to the nine interrupt lines is also in the logic area of the patchboard The digital computer is interrupted whenever the logic signal patched to any interrupt line becomes true Devices which have both analog and logic signals such as comparators and digitally controlled electronic switches have the logic inputs and outputs terminated in the logic section of the patchboard Corresponding analog inputs and outputs are terminated in the analog areas 2 1 2 Analog Components The lower two thirds of the patchboard is reserved for analog computing components Presently each of the two AD FIVE computers has the following component complement 10 30 integrators gains of 1 10 100 1000 10000 24 summers 30 inverters summers 24 switch summers 120 digital coefficient units 14 bits sign 8 track
6. bit words The data transfer rate of the DECtape system is 5K words s The DECtape is used to save files The user stores data and programs generated during a session at a terminal on the disk When runs are completed desired data and files can be transferred from the disk to DECtape for backup purposes All data transfers to from DECtape utilize a DMA interface 4 2 3 Magnetic Tape The 9 channel magnetic tape system 18 consists of a 11 transport controller a TU10 tape transport and a magnetic tape The TM11 controller will control up to 8 transports and is capable of operating with 7 or 9 channel tape transports The diameter of the magnetic tape reel is 26 7 cm 10 5 in and the reel contains 732 m 2400 ft of tape its capacity is 6 million words and the data transfer rate is 18 000 words s 11 lata transfers to from tape utilize a DMA interface 34 The magnetic tape is used to store programs and large volumes of data It is the medium used when exchanging data and programs with the CRNL Computing Center and outside companies The contents of the user disk the second RPO2 are stored on magnetic tape every Monday morning and saved for three subsequent 4 3 User Interface Five terminals can be connected to the PDP 11 45 computer and two of them the LA30 DECwriter and VTO5 video display are provided with switches that allow them to be connected to the PDP 11 55 computer Furthermore one of the HP26
7. divided into two groups of 16 with a single hold control for each group The two hold controls are terminated in the logic area of the patchboard The hold feature is used to eliminate data time skew that would result fren the finite sampling time for each channel Each Datawest 301 Series ADC is a semi parallel device utilizing two eight bit conversions The result of the first conversion is entered into an eight bit high accuracy digital to analog converter The second conversion is a digital representation of the difference between the digitai to analog converter output and the analog voltage input The results of the two conversions are summed to form a 15 bit 14 bits sign word that is accessed by the PDP 11 computer The least significant bit of the output word corresponds to 1 millivolt of the analog input The permissible analog input range is 10 volts and the throughput rate is 100 kHz 3 4 Digital to Analog Converters Each analog console has 16 multiplying digital to analog converters contained in a chassis in the bottom of the analog computer cabinet These devices are very similar to the digital coefficient units except that they have two buffers the initial buffer and the final buffer for storing data settings The value at the output of the DAC is always the D product of the input signal and the setting contained in the final buffer Like DCUs DACs are four quadrant devices that receive their data from eithe
8. for analog models 4 3 3 HP2640A Interactive Display Terminals There are two Hewlett Packard HP2640A interactive display terminals 22 Each displays 24 lines of 80 charac ters which are formed by a 7 x 9 dot matrix and each is set to transmit and receive at 2400 baud the maximum permissible value The terminals have four character sets 128 character Roman 96 character Roman subscript 96 character mathematics and 64 character line drawing Display enhancement features include blinking under lining half bright and inverse video Each terminal contains 5K bytes of RAM memory which stores about 3 screens of text 36 A HP2640A terminal has block made capabilities When the terminal is in this mode typed data are displayed but not transmitted to the computer until requested by the computer or until after the ENTER key has been pressed and the computer has responded Otherwise the terminal is in character mode and data are transmitted typed Each of the terminals can perform any of the functions above but they are used primarily for the preparation of system and maintenance programs and also set up and check out and control programs for analog models As well they are used for the preparation of Reactor Control Branch engineering files user s guides newsletters etc As already mentioned one of the terminals can be switched to the Computing Centre to permit running of jobs on the CDC CYBER 170 6
9. his assigned area This prevents the user from destroying other programs or the system executive programs The user program i e task may occupy as many as 8 memory pages and each page may be up to 4096 words in length The relocation feature of the memory management unit allows the base address of each page to be any multiple of 32 words in the 128K where K 1024 words of physical address space The memory management unit adds 90 ns to every memory reference when it is enabled 29 The UNIBUS priority arbitration unit regulates UNIBUS requests and transfers control of the UNIBUS to the requesting device with the highest priority The PDP 11 45 digital computer contains 124K words of parity core memory the full complement available with a cycle time of 980 ns The PDP 11 55 digital computer contains 32K words of parity bipolar memory with a cycle time of 300 ns and 64K of MOS semiconductor memory with a cycle time of 475 ns System communication is done via the asynchronous UNIBUS The UNIBUS is a common set of signal wires that connect the processor of one PDP 11 mainframe its memory and peri pherals see Figure 8 Communication between two devices on the UNIBUS is considered a master slave relationship in that one device has control of the UNIBUS during any operation This device the UNIBUS master controls the UNIBUS when com municating with another device called the slave The maximum transfer rate is one 16 bit wo
10. if memory is available Tasks can be defined as checkpointable which allows them to be swapped out of memory when space is required for execution of high priority tasks Optionally they can be declared as multi user tasks which are shareable allowing more than one user to have access to the pure part of the task in parallel by duplicating only the data dependent code impure in memory The pure part of a task is the part that never changes but Some multi user tasks have data dependent code only On the Program Development System the main advantage of the IAS executive is its multi user capability We presently utilize four terminals on a full time basis and can use the VT05 video display as a fifth terminal as the need arises These terminals are used mainly for editing compiling assembling task building and running tasks The tasks produced consist of system programs utility programs maintenance programs set up and checkout programs and control programs for simulation runs All these tasks are stored on the disk All tasks not related to simulations can be loaded and run when requested whereas tasks related to simulations are transferred to the Hybrid Computer via the interprocessor link The PDP 11 45 digital computer contains 126 976 words of core memory The layout of this memory is as follows Main executive 20 960 words Monitor Control Routine Other handlers and file control routines 23 168 words tel
11. is essential for efficient analog and hybrid program development and debugging IHI is useful in a hybrid system in much che same way that on line debugging features are often indispensable in digital 46 program debugging IHI has all the necessary statements via subroutine calls to push the buttons on the analog computer as well as the basic hybrid communication capability provided by the HCRs IHI also allows direct access to the components in the analog computer by means of convenient analog device mnemonics 5 5 Utility Programs Many utility programs have been purchased or written by our personnel since the arrival of the system These and some of the utility programs provided with the system are listed below The following utilities are available on both the Hybrid Computer and the Program Development System i The Peripheral Interchange Program PIP 34 is an IAS file utility program that transfers data files from one standard FILES 11 device to another i e PIP can copy files from one device to another delete files rename files list file directories set the default devices and UIC for PIP operations unlock files and spool files for printing ii The Line Text Editor EDI 34 is a line oriented editor that allows for the creation and modification of text files iii The Set up and Check out Utility SCU 35 program takes the user s data and patching description and
12. magnetic tape 11 DECtape RP11 RP02 03 disk pack RK11 disk cartridge DL11 ASR 33 teletype 11 paper tape RJ03 04 fixed head disk 4 disk pack and TJU16 magnetic tape Of the above controllers only the 11 TC11 RK11 and the equivalent of the RPll are available in the Program Development System of the Dynamic Analysis Facility When the bootstrap is used basic CPU and memory diagnostics are run and then the console emulator program is entered The four console functions LOAD ADDRESS EXAMINE DEPOSIT and START can be exercised To initiate a bootstrap loader a two letter name of the device to be booted is typed at the terminal i e DK for RK05 disk The MR11 DB unit 20 in the PDP 11 55 digital computer is a 64 word bootstrap loader for the following bulk storage devices RFll disk 11 disk 11 dual DECtape TM11 9 channel magnetic tape RP11 disk and RCll disk xy a Of the above controllers listed only the RK11 is available in the Hybrid Computer of the Dynamic Analysis Facility The disk bootstrap is used to load maintenance programs and the IAS executive 4 1 4 Floating Point Processors The floating point processor FPP 21 model FPll B in the PDP 11 45 digital computer performs all floating point arithmetic operations and converts data between integer and floating point formats This processor has overlapped operation with the CPU high speed
13. modules a selection of digital logic elements such as gates flip flops and counters These logic elements are invaluable for the control of problem solutions Since the logic states may be controlled by the magnitude and sign of problem variables USER OUTPUT USER INTERFACE DEVICES INTERFACE STORAGE FILE ANALOG DEVICES COMPUTER Ss TRANSFERS ims CONTROL AND FUNCTION DEVELOPHENT GENERATION STORAGE DEVICES COMMUNICATION BETWEEN ANALOG DIGITAL COMMUNICATION BETWEEN ANALOG DIBITAL PROCESSING PROCESSING OUTPUT j OUTPUT DEVICES DEVICES ANALOG ANALOG x HYBRID COMPUTER PROGRAM DEVELOPMENT SYSTEM FIGURE 1 FUNCTIONAL DIAGRAM OF THE DYNAMIC ANALYSIS FACILITY signals from the analog computer control system and accurate timing pulses contained in the analog computer In a hybrid configuration the digital computer can also control the execution of the logic program As stated above the analog portion of the Dynamic Analysis Facility consists of two Applied Dynamics AD FIVE analog computers 2 These are general purpose machines which may be used to solve any problem that lends itself to solution on an analog computer The reference voltage of the AD FIVE computer is 10 volts Apart from their hybrid mode of operation the two analog consoles may be used independently as stand alone analog computers They may also be connected together to form one large analog com
14. store networks 48 digitally controlled electronic switches 12 hard limiters multipliers convertible log generators sine cosine generators One integrator solves one first order differential equation Therefore one analog computer of the Dynamic Analysis Facility can solve a set of thirty differential equations in parailel In the hybrid mode a set of more than thirty equations may be solved by sharing multiplexing the analog hardware This is done by breaking the equation set into subsets for which there is sufficient hardware and then computing a subset of the solution The solution subsets are combined to form the complete solution This method inherently serializes the solution and the analog computer must run faster than real time in solving the subsets to obtain a real time solution of the set Usually the maximum speed of this method is limited by the digital computer A distinguishing feature of the Dynamic Analysis Facility is the set of 120 digital coefficient units DCUs in place of servo set potentiometers in each of the AD FIVE analog computers DCUs are single buffered multiplying digital to analog converters which can be set at high speed typically 6 us DCU by direct memory access Their four quadrant operation can replace a potentiometer plus inverter while their low output impedance results in insignificant loading effects Settings greater than 1 are permitted if the output does not exceed 10 volts T
15. 1 assembler MAC BASIC and the Interactive Hybrid Interpreter IHI These processors and their attributes are discussed below FORTRAN IV PLUS F4P software 27 is a complete implementation of FORTRAN based on American National Standard ANSI FORTRAN 66 with numerous extensions The FORTRAN IV PLUS compiler produc2s PDP 11 machine code optimized for execution time on a PDP 11 computer with a floating point processor Timing tests were performed on tasks compiled with the manufacturer s standard FOR compiler and similar ones compiled with F4P Tasks compiled with F4P ran 50 60 faster and the task images were of the same size or smaller Since the F4P compiler produces machine code it is easy to debug a FORTRAN program because the octal debugging technique ODT program may be used This feature is not available with FOR Users tend to program mostly in FORTRAN as it is a universal higher level language and is easier to use than assembler language Programming in assembler language would increase the speed of a program by only 10 at most and this could be achieved only by a very proficient programmer The assembler language is also much more difficult to learn than FORTRAN 44 The RATFOR processor 28 is a FORTRAN preprocessor which supports a number of language extensions not found in FORTRAN It allows use of structured programming techniques in a FORTRAN program thereby generating an easy to understand program The R
16. 40A terminals can be switched between the PDP 11 45 computer and the CDC CYBER 170 6600 computer system in the CRNL Computing Center This is accomplished via a switch modem and telephone line to the CDC 3300 computer All of these input output terminals can be used for composing files editing files forwarding messages to the computer receiving instructions and data from the computer performing on line debugging 4 3 1 LA30 DECwriter The LA30 DECwriter 18 prints from a set of 64 characters at 300 baud Data are entered via the 96 character 35 keyboard and hard copy is produced on 25 cm 9 7 8 inch wide paper the characters being formed by a 5 x 7 dot matrix The LA30 terminal will perform the functions listed above but it is used primarily as a hard copy device for System generation software development and initiation of new users This terminal is used primarily as the console terminal for both the Hybrid Computer and the Program Development System 4 3 2 VT52 Video Display The VT52 video terminal 18 has a display which holds 24 lines of 80 characters of the upper and lower case 11 type It has a 128 character set and the characters are formed by a 7 x 7 dot matrix It is set to transmit or receive at 2400 baud This terminal can perform any of the functions above but it is used primarily for the preparation of system and maintenance programs and also set up and check out and control programs
17. 600 computers from the Dynamic Analysis Laboratory 4 3 4 VTO5 Alphanumeric Video Display The VTO5 terminal 18 consists of a CRT display and a 96 character keyboard The CRT can display up to 1440 characters at a time from a 64 character set The terminal displays 20 lines of 72 characters which are formed by a 5x 7 dot matrix and is set to transmit or receive at 2400 baud the maximum permissible value The VT05 terminal can perform any of the functions above but it is used primarily as an input output terminal for simulation runs on the Hybrid Computer 4 4 Data Output Device The Versatec 1100A printer plotter 23 part of the Program Development System consists of a model C PDP 11 matrix controller and the matrix electrostatic printer plotter 37 As a printer it prints 132 characters per line at 500 lines per minute High contrast 7 x 9 dot matrix charac ters are printed on 28 cm 11 inch wide paper As a plotter it perates at up to 3 cm 1 2 inches s paper speed with a nib density of 100 dots inch Maximum plot width is 26 cm 10 24 inches The 1100A system also has simultaneous print plot capability and a DMA channel is used for data transfer to it when in the plot mode The printer plotter is used mainly as a printer for listing programs as they are edited assembled and compiled but it is also used as a plotter to plot data for example sampled analog information and Fast Fourier Transforms 4 5 Int
18. ATFOR processor translates programs written in the RATFOR language into LuRTRAN This output is then presented to the FORTRAN compiler for processing If the user desires to write a program that will execute in the shortest time possible then he programs in the MACRO assembler 29 language This language has an instruction complement which uses the flexibility of the general purpose registers to provide over 400 powerful instructions If the user wishes to interact with his program and is not concerned about speed of execution then he can use the BASIC 30 and IHI 31 languages BASIC and IHI are conversational high level programming languages which use straightforward English like statements and familiar mathe matical notation to perform operations Compared to BASIC IHI has an advantage in its hybrid capabilities described in section 5 4 All of these processors are used in the Program Development System The user assembles compiles and then task builds his program on the system If the task is to be run on the Hybrid Computer it is then transferred via the interprocessor link Ail these processors except BASIC may be utilized in the Hybrid Computer if required 5 4 Hybrid Software The hybrid software in the Hybrid Computer consists of a hybrid handler hybrid communication routines and an Interactive Hybrid Interpreter 45 Under IAS the AD FIVE device handler is the software interface between the analog and digita
19. CA 00 64 A AECL 6581 L NERGIE ATOMIQUE DU CANADA LIMIT E ATOMIC ENERGY OF CANADA LIMITED THE DYNAMIC ANALYSIS FACILITY AT THE CHALK RIVER NUCLEAR LABORATORIES Installation d analyse dynamique Chalk River D S ARGUE and W T HOWATT Chalk River Nuclear Laboratories Laboratoires nucl aires de Chalk River Chalk River Ontario October 1979 octobre ATOMIC ENERGY OF CANADA LIMITED THE DYNAMIC ANALYSTS FACILITY AT THE CHALK RIVER NUCLEAR LABORATORIES by D S Argue and W T Howatt Chalk River Nuclear Laboratories Chalk River Ontario 170 October 1979 AECL 6581 Installation d analyse dynami que Chalk River par D S Argue et W T Howatt R s um L installation d analyse dynamique de Laboratoires nucl aires de Chalk River de L Energie Atomique du Canada Limit e est un ordinateur hybride comprenant deux calculateurs analogiques AD FIVE de Applied Dynamic International un calculateur num rique PDP 11 55 de Digital Equipment Corporation DEC et un syst me de r alisation de programme fond sur un calculateur num rique DEC PDP 11 45 Ce rapport d crit les fonctions des divers mat riels compo sant l installation d analyse dynamique ainsi que leurs interactions On y trouve galement une br ve description des programmes mis la disposition des utilisateurs L Energie Atomique du Canada Limit e Laboratoires nucl aires de Chalk River Chalk River Ontario 1J0
20. T F As mentioned previously the logic components are used to control the problem solution The comparators provide an interface from the analog components to the logic section while devices such as switch summers are able to alter analog variables on command from a logic signal Intergrator modes and time scales may also be controlled over ridden by logic signals Ciocked logic elements utilize a two phase clocking system to eliminate race problems Many console control logic signals are also terminated i the logic section of the patchboard Some of these signals are used for slaving but in hybrid problems they are often valuable for synchronizing logic programs with the mode of the analog console The reference timer provides a source of fixed period pulses l us wide Periods ranging from 1 s to 10 us in decade Steps are simultaneously available Variable period pulses l us wide with periods from 10 ms to 1 s in decade steps are available when the console is in the X1 time scale The period of these variable pulses is altered by the console time scale controls Thus if the integrator time scale is made faster the logic components which are using the variable source of pulses will also run faster by the same factor This ensures that the logic program always runs in the same time scale as the analog program Many of the logic computing elements have both switches and indicators associated with them The switches
21. cated in the analog computer cabinet The HIF contains the necessary hardware to access the analog computer control system the DAC DCU system the hybrid interface register and the console status register and digitizei analog data from the digital ratiometer Data and instructions are routed to all circuit boards in the HI hassis by a bus which is physically the motherboard of chassis Only the circuits that are addressed by the current instruction respond to the signals Any hardware that is capable of assuming control of the HIF bus has a bus priority arbitration circuit to ensure that control of the bus is obtained only when it is not being 20 used by another device The priority of these devices is determined by their physical location in the HIF chassis While the HIF bus is normally used only for hybrid communications it is also an integral part of the mechanism for setting DACs and DCUs from the control panel of the analog computer DACs and DCUS may receive their data from the digital computer in three different ways The first is called the slow speed path The digital computer sets the device in the same sequential manner an operator would from the control panel of the analog computer This is done with a software subroutine that pushes the buttons in the proper sequence This takes about 40 ms per device faster method permits the digital computer to directly load the DAC DCU control syst
22. d Only Memory and MR11 DB Bootstrap Loader DEC 11 HBMAA E D Digital Equipment Corporation Maynard Massachusetts 1974 August PPll Floating Point Processor Maintenance Manual DEC 11 HPFB D Digital Equipment Corporation Maynard Massachusetts April 1973 2640A Interactive Display Terminal Owner s Manual Hewlett Packard 11000 Wolfe Road Cupertino California Operating Manual C PDP11 DMA 18 Bit Controller Versatec Inc Santa Clara California 1975 August IAS Documentation Directory AA 2500D TC IAS Version 3 0 Digital Equipment Corporation Maynard Massachusetts 1978 October IAS Device Handlers Reference Manual AA HOO4A TC Digital Equipment Corporation Maynard Massachusetts 1978 October 26 27 28 29 30 31 32 33 34 35 36 37 54 RSX IAS DECnet Users Guide AA 5182A TC Digital Equipment Corporation Maynard Massachusetts 1979 March Fortran IV Plus User s Guide DEC 11 LFPUA B D Digital Equipment Corporation Maynard Massachusetts 1975 March B Switzer and P D McMorran AECL internal files Chalk River 1977 April IAS RSX 11 MACRO 11 Reference Manual DEC 11 0IMRA B D Digital Equipment Corporation Maynard Massachusetts 1976 December D S Argue AECL internal files Chalk River 1977 December System 511 User s Manual Interactive Hybrid Interpreter Applied Dynamics International Ann Arbor Michigan 1976 No
23. e convenient to use the above method since VE it provides inherent synchronization with the other variables and the X axis drive is automatically scaled if the analog computer time scale is altered One Houston Instrument Series 2000 Omnigraphic X Y recorder 13 is mounted in each display rack Each recorder accepts either standard English 8 5 x 11 inch or 11 x 16 5 inch paper and also standard European A4 210 x 297 mm or A3 297 X 420 mm paper Any intermediate or smaller sizes will also work with the vacuum hold down system Disposable fibre tip pens in black red or blue are used and the electric pen lift is actuated either remotely or locally The pen lift and the X Y sweep using the reccrder time base can be controlled from the analog computer patch board 3 COMMUNICATION BETWEEN ANALOG AND DIGITAL COMPUTERS High speed communication between the analog and digital computers an essential part of a modern hybrid computer is established via two interfaces 14 The interfaces are coupled together to form the two way communications path Figure 5 shows the location of the interfaces within the Hybrid Computer of the Dynamic Analysis Facility The Remote Interface RIF is located in the PDP 11 55 digital computer cabinet The Hybrid Interface HIF is located in the analog computer Electrically these two interfaces work together as an extension of the digital computer s UNIBUS There is one unique RIF and HIP
24. em in the HIF with both the command word and the data word The DAC DCU control system thez ioads the data into the addressed device This takes about 14 us per device The fastest method for setting a group of devices with continuous addresses is Direct Memory Access DMA which takes about 6 us per device with a startup time of 6 us The ability to treat all of the analog computer s coefficient devices as high speed digital to analog converters results in a very powerful facility for hybrid computation It would not be possible to realize the full benefit of analog computer hardware multiplexing in real time with conventional servo set potentiometers 3 3 Analog to Digital Converters The digital computer is able to read the analog voltage at the output of any addressable analog component with the digital ratiometer While this is a very convenient method for the set up and check out of a problem it is not fast enough for high speed hybrid computation 2 2T 2 The two Datawest analog to digital converters 5 located in the digital computer cabinet are used when fast sampling rates are required The converters are located in the digital section of the hardware so they may be interfaced directly to the UNIBUS This permits the highest possible throughput since the HIF RIF path has only one way DMA transfers from memory to the DACs and DCUs Each ADC has 32 channels all with simultaneous sample hold capability The channels are
25. ere running as fast as requested by the users 16 Therefore it was decided to separate these two duties and the PDP 11 55 computer 17 was installed in April 1978 as the digital processor for the Hybrid Computer The PDP 11 55 computer was chosen for its higher system performance obtained by the use of high Speed bipolar semiconductor memory instead of magnetic core memory Bipolar memory is 2 7 times faster than core memory and thus speeds up instruction execution by a factor of about 2 5 The PDP 11 45 computer then became the digital processor for the Program Development System The PDP 11 45 and PDP 11 55 digital computers are powerful tools for high speed real time applications and for large multi user multi task applications As described in the Introduction a feature required by the analysts of the Dynamic Analysis Section is real time simulation which implies a high speed of computation Large simulation models require multiple tasks for controlling the model and analyzing the data from the model A Program Development System has many users which implies a multi task environment Therefore the PDP 11 45 computer was our choice for program development due to its multi user environment The PDP 11 55 computer was our choice for dynamic simulation studies because of its high system performance due to the use of high speed bipolar semiconductor memory The 11 45 computer see Figure 6 consists of the mainframe KWl
26. erprocessox Links The DAl1 BD 18 interprocessor link provides a means for half duplex DMA data transfer between the PDP 11 45 digital computer of the Program Development System and the PDP 11 55 digital computer of the Hybrid Computer Using the DMA facilities of each computer the link transfers either single words or blocks of data from the memory of one machine to the memory of the other The transfer rate can be as high as 500K words s The interprocessor link is used to transfer files between the Program Development System and the Hybrid Computer These files are usually the set up ind check out program control program and data files that were developed on the Program Development System and are required for the setting up and running of an analog model Output results from the model are sometimes sent to the Program Development System to be plotted or listed on the line printer 38 5 SOFTWARE The IAS operating system used in both the Hybrid Computer and the Program Development System is disk based priority ordered and significant event driven it allows multiprogramming and it runs in real time The IAS operating system in the Program Development System with utilities and language processors meets the ease of programming criteria for developing detailed system models mentioned in the Introduction In the Hybrid Computer this operating system augmented by hybrid software and utilities meets the c
27. ers for the horizontal axis for X Y type presentations Each analog console has the facility for controlling the following oscilloscope functions from the patchboard i remote erase ii external single shot reset iii Z axis i e intensity iv external trigger 2 2 2 Strip Chart Recorders Frequently it is necessary to examine the relationship of several parameters which vary as functions of time The easiest way to do this is to simultaneously record all the variables of interest on a multi channel strip chart recorder There are two strip chart recorders available in the Dynamic Analysis Laboratory a 4 channel and an 8 channel Gould Brush Series 1707 Mark 200 system 9 10 Each oscillograph has 12 chart speeds from 0 05 to 200 mm s Traces are produced by a pressurized ink system writing on special paper The system frequency response is flat to 55 Hz full scale and to 100 Hz at reduced amplitude The 8 channel recorder uses Brush model 13 4215 32 DC preamplifiers 11 Each amplifier feature calibrated zero suppression and a switchable 5 Hz filter The input sensitivity 15 steps are 1 2 5 10 20 50 100 millivolts division and OFF Each of these steps may be used with a X100 attenuation multiplier The 4 channel recorder uses Brush model 13 4215 12 high gain DC preamplifiers 12 Each amplifier has calibrated zero suppression and input sensitivity steps of 0 10 0 20 0 50 1 2 5 10 20 50 100 mil
28. ersistence feature is ideal for displaying either slow analog solutions or a family of solutions The mainframes are eguipped with the readout option which is convenient for recording oscilloscope settings when photographs are used for permanent records Separate amplifiers for the vertical and horizontal axes of the display screen are available in the Dynamic Analysis Laboratory The plug in amplifiers for the vertical axis are Tektronix types 7A18 2 units 4 7A22 5 and 7A26 6 The 18 and 7A26 units are dual trace amplifiers which when used with the R7613 mainframe give system vertical bandwidths of DC 75 MHz and DC 100 MHz respectively These amplifiers have input sensitivities from 5 millivolts division to 5 volts division FIGURE 4 ONE OF TWO DISPLAY RACKS 14 The 7A26 differential amplifier plug in limits vertical bandwidth of the oscilloscope system to about 1 MHz This amplifier has high sensitivity 10 microvolts division and switch selectable high frequency and low frequency filter cut off points It also has the capability of biasing DC offsets While it is useful as an output device for analog solutions its main use is as a maintenance and debugging tool The plug in units for the horizontal time base are Tektronix types 7B50 7 and 7B53N 8 Both units offer sweep rates from 5 s division to 50 ns division Only the 7B53N unit offers delayed sweep but both time base units may be used as amplifi
29. etype DECtape message output etc TOTAL 44 128 words This leaves 82 848 words available for user and system tasks The main advantage of the IAS executive on the Hybrid Computer are the real time and multiprogramming capabilities The control of a simulation requires at times many different tasks which are run at different priorities and therefore the multiprogramming technique is used However for simulation studies which must run in real time the IAS executive response to interrupts is not fast enough The time from the occurrence of the interrupt until the portion of the device handler 25 that services the interrupt was entered is 3 3 ms Therefore we have modified the hybrid handler to reduce the response time to 125 us This is described in Section 5 4 under hybrid software The PDP 11 55 digital computer contains 98 304 words of semiconductor memory one third of which is bipolar and two thirds is MOS 42 The layout of this memory is as follows Main Executive 16 480 words Monitor Control Routine 2 048 words Other handlers and file control routines 21 248 words teletype message output etc TOTAL 39 776 This leaves 58 528 words available for user and system tasks 5 2 DECNET IAS DECNET IAS V2 1 software 26 was purchased to allow communication between the Program Development System and the Hybrid Computer This software allows device sharing i e access to the peripheral d
30. evices of a remotely located system file sharing i e access to files stored on a remote system program sharing i e the running of a program on the remote system inter task communication i e creation of a data path for transfer of information between two tasks in the same system or in remotely located systems Presently we are using only two of the above functions i e device sharing and program sharing Users of the Hybrid Computer access the disk and the line printer on the Program Development System Thus all control programs for hybrid simulations are developed on the Program Development System and transferred to the Hybrid Computer for execution via the interprocessor link All the functions of the DECNET software will be utilized when large simulations are developed and when process hardware such as control computers is added to the system 43 The DECNET software must be in memorv only when required It can be loaded or removed at any time but when first loaded an initialization process takes place requiring 14 912 words of memory After the initialization has been completed DECNET occupies 17 888 words of memory 5 3 Language Processors Many languages are available to the user of the Dynamic Analysis Facility and the language he chooses depends greatly on the problem at first hand and how he wishes to Solve it The processors available are FORTRAN IV PLUS F4P RATFOR RAT MACRO 1
31. for each analog console Because of this two independent hybrid programs may be run concurrently on the two analog consoles as Long as the PDP 11 55 digital computer is capable of servicing both programs Multi conductor cables connect the analog and digital computers via their respective interfaces 17 ANALOG ANALOG CONSOLE 0 CONSOLE 1 HYBRID HYBRID INTERFACE 0 INTERFACE 1 REMOTE REMOTE INTERFACE 0 INTERFACE 1 PDP 11 55 DIGITAL COMPUTER FIGURE 5 BLOCK DIAGRAM OF THE HYBRID COMPUTER 18 The HIF RIF communication path is used primarily to send pushbutton commands from the PDP 11 to the AD FIVE control system send settings from the PDP 11 55 computer to the coefficient devices read digitized data from the DRM into the PDP 11 memory and read the status of the AD FIVE HIF or RIF The transmission of a data or command word by the HIF RIF system requires less than 2 ys While the above satisfies the requirements for a hybrid computer system another path exists for reading digitized analog variables into the PDP 11 55 computer at very high speed This is accomplished by the Datawest analog to digital converter see section 3 3 below which is independent of the HIF RIF path 3 1 The Remote Interface The Remote Interface located in the PDP 11 55 digital computer cabinet receives instructions and data from the PDP 11 UNIBUS and data from the analog computer Depending on the instruction
32. he maximum setting is 1 6383 They are 15 bit devices 14 bits sign with the least significant bit worth 1 millivolt Data is sent to the DCU control system in twos complement binary format where it is converted to a magnitude and sign for loading into the DCU register The AD FIVE integrator modes are switched by solid state field effect transistor switch circuits rather than relays The four time scales are obtained by switching both the feedback capacitor and the input resistor dependent upon which scale is desired Integrator characteristic times range from 1 s to 0 1 ms All of the integrators may be configured as 6 input summers if necessary Two individual over riding mode and time scale controls are available for each area of the patchboard The value of the output of every addressable computing component can be read via the digital ratiometer DRM located in the control panel This capability makes the DRM invaluable for the set up and check out phase of the problem solution however its relatively low speed precludes its use in high speed computation A control panel with a complete complement of pushbutton switches is accessible te the operator and affords him complete control of the analog computer Settings may also be entered into the coefficient devices via this panel In the hybrid mode special software routines permit the digital computer to push the buttons on the control panel 2 2 Data Output Devices
33. hs between the digital and analog computers on the Hybrid Computer are checked by the following maintenance programs i The Linkage Diagnostic Program LKD 52 enables the user to check the hardware operation of the AD FIVE computer and the HIF RIF interface ii The COEF program 53 checks the DMA and NON DMA path for DACs and DCUs on the AD FIVE computer iii The INTEST program 54 checks all operations of the integrators on the AD FIVE computer 50 iv The ADC program 55 checks most aspects of the Datawest ADC operation v The HYCOM program 56 checks the AD FIVE hybrid communication data lines 6 SYSTEM UTILIZATION AND RELIABILITY On average there are nine people using the system on essentially a full time basis Five of them are develop ing and running simulations and four are maintaining and developing system hardware and software Between them they use the four terminals on the Program Development System 90 95 of the time The analog consoles on the Hybrid Computer are used about 30 of the time The reason for this difference in utilization is that preparation of digital programs and patching of the analog boards requires much more time than actual production runs on the analog computers The system has been reliable Over the past 4 years the PDP 11 45 digital system was down for 1 2 weeks mainly because of problems with the disks and magnetic tape The PDP 11 55 computer had several early bipo
34. ing the plant must be operating in real time It is well known that digital computers are inherently more accurate than analog computers However since the accuracy of any simulation is determined largely by the accuracy of the input data i e the physics and engineering parameters and to a lesser degree by the method of computation the analog computer is quite adequate for dynamics simulation and control studies The digital computer is superior to the analog com puter in the handling of large amounts of data or function arrays and the implementation of complex logic decisions On the other hand high speed parallel computation is best done by analog computers Therefore the logical choice for large Scale dynamic simulation is a facility which combines the best features of both computer types i e the hybrid computer As a result of the arguments presented above a large modern hybrid computer system was purchased by the Reactor Control Branch in 1975 March This system called the Dynamic Analysis Facility consisted of two Applied Dynamics Inter national ADI AD FIVE analog computers and a Digital Equipment Corporation DEC PDP 11 45 digital computer In 1978 April a DEC PDP 11 55 digital computer was added to the system which was subsequently reconfigured into a Hybrid Computer comprising the PDP 11 55 digital and the two AD FIVE analog computers plus peripherals and a Program Development System based on
35. iver 1977 June D S Argue AECL internal files Chalk River 1977 March P L Hanschke and C B Lawrence AECL internal files Chalk River 1977 August P D McMorran AECL internal files Chalk River 56 52 D S Argue and W T Howatt AECL internal files Chalk River 1977 March 53 D S Argue and W T Howatt AECL internal files Chalk River 54 D S Argue and W T Howatt AECL internal files Chalk River 55 D S Argue and Howatt AECL internal files Chalk River 56 D S Argue and W T Howatt AECL internal files Chalk River ISSN 0067 0367 To identify individual documents in the series we have assigned an AECL number to each Please refer to the AECL number when re questing additional copies of this document from Scientific Document Distribution Office Atomic of Canada Limited Chalk River Ontario Canada KOJ 1J0 Price 5 00 per copy ISSN 0067 0367 Pour identifier les rapports individuels faisant partie de cette s rie nous avons assign un num ro AECL chacun Veuillez faire mention du num ro AECL si vous demandez d autres exemplaires de ce rapport au Service de Distribution des Documents Officiels L Energie Atomique du Canada Limit e Chalk River Ontario Canada KOJ 1J0 Prix 5 00 par exemplaire
36. ized when the Dynamic Analysis Facility becomes part of the computer network currently being implemented at the Chalk River Nuclear Laboratories 7 ACKNOWLEDGMENTS The authors would like to thank our colleagues P D McMorran and E O Moeck for reviewing this report and giving us some helpful suggestions 8 REFERENCES 1 E O Moeck Proposal for a New Dynamic Analysis Facility at Chalk River unpublished Atomic Energy of Canada Limited report CRNL 1000 Chalk River 1974 January 2 Applied Dynamics AD Five Reference Manual Chapters 1 5 Applied Dynamics Ann Arbor Michigan 3 Tektronix 7613 R7613 Storage Oscilloscope Operator s Manual Tektronix Incorporated Beaverton Oregon 1972 4 5 6 7 8 9 10 11 12 13 14 52 Tektronix 7A18 7A18N Dual Trace Amplifier Instruction Manual Tektronix Incorporated Beaverton Oregon 1974 Tektronix 7A22 Differential Amplifier Instruction Manual Tektronix Incorporated Beaverton Oregon 1969 Tektronix 7A26 Dual Trace Amplifier Instruction Manual Tektronix Incorporated Beaverton Oregon 1974 Tektronix 7850 Time Base Instruction Manual Tektronix Incorporated Beaverton Oregon 1974 Tektronix 7B53N Dual Time Base Instruction Manual Tektronix Incorporated Beaverton Oregon 1971 Mark 200 Recorder 1707 Series Manual Manual part number 801707 120 Gould Incorporated Brush Instruments Division
37. l L line clock 9301 mu_ device bulk storage boctstrap loader and FP11 B floating point processor The storage devices for the system are a RK05 disk drive a CDC 9762 disk drive a TU56 DECtape transport and a 9 channel TU10 magnetic tape transport 24 ECH I eem EH HALNANOD SP TT ddd 9 SANDIA lt 25 Users access the computer via any of five terminals a VTO5 video display a LA30 DECwriter a VT52 video display and two HP2640A video displays The output device for the system is a Versatec 1100A electro static printer plotter which produces listings and plots The interprocessor link is a DAll BD interface The DP 11 55 computer see Figure 7 consists of the mainframe KW11 P programmable real time clock MR11 DB multi device bulk storage bootstrap loader and FP11 C floating point processor The storage devices for the PDP 11 55 computer are two RK05 disk drives the user interfaces are a VT05 video display and LA30 DECwriter and the interprocessor link is a DAll BD interface The characteristics of the above hardware units and the inter actions between them are described below 4 1 Central Processors 4 1 1 The PDP 11 45 and PDP 11 55 Mainframes The central processor unit 17 of either the PDP 11 45 or the PDP 11 55 conputer has a cycle time of 300 ns and con tains sixteen general purpose registers an arithmetic and logical process
38. l computers As one of its functions the handler must service interrupts generated by the analog computer Because of the continuous nature of analog computing it is important that these interrupts be acted upon as soon as possible The handler supplied with the system was found to be too slow in servicing interrupts 3 3 ms and hence was modified to improve this response time to 125 us This modification included writing some Fast Interrupt Service FIS routines 32 When an interrupt occurs from the analog console control is passed to one of the FIS routines These routines are initialized by the user through a FORTRAN CALL statement to pass the parameters and prepare for interrupts Capabilities provided are transport delays function generation function storage and playback high speed analog to digital conversion with buffer ing output of a stored function to an oscilloscope or plotter The Hybrid Communication Routines HCRs 33 provide all the basic AD FIVE control panel operations These routines are written in assembler language and they communicate with the analog consoles through the hybrid handler The HCRs can be accessed from FORTRAN MACRO and the Interactive Hybrid Interpreter IHI and are used to set up and control the analog console s The Interactive Hybrid Interpreter IHI 31 is an interactive easy to use interpretive programming language Interactive hybrid communication capability
39. lar memory failures but has since been very reliable The analog computers were also down for 1 2 weeks and require on a continuing basis about one man day a month for repair and calibration Many of the initial problems were traced to a bad batch of operational amplifiers and to poorly soldered joints This is to be expected for a new piece of hardware especially one that contains several design innova tions From an overall viewpoint the Dynamic Analysis Facility has met our expectations as a powerful computing system in all respects and exceeded them in others For example the foreground background operating software envisaged earlier 1 has been ocquired in the form of a general multi user priority ordered system that provides considerably more flexibility in the utilization of the Facility EI As expected the software supplied by the manufac turers of the various components of the Dynamic Analysis Facility digital analog peripherals while acceptable for general purpose hybrid computation had to be considerably revised and extended to meet our special needs In common with the owners and operators of other computing systems we find that our Facility is in state of continuous change The software is being improved and ex panded while hardware modifications and additions are in progress to make the Facility even more efficient and to increase its capability A major advance in this regard will be real
40. livolts division and OFF Each of these steps may be used with a X100 attenuation multiplier Each recorder has two event marker pens one on the extreme right of the chart and the other on the extreme left These markers may be switched to provide a mark every one Second or every ten seconds An external source may be used to drive the markers when convenient The oscillograph or pen motor and chart drive system has three possible control modes partial remote full remote and local When the PARTIAL REMOTE button is depressed chart drive on off control is transferred to the remote location Full remote also transfers the chart speed control to the remote location All control functions are available at the oscillograph front panel when in the local control mode The patchboard on each analog computer has the facility for controlling the recorders in partial remote mode and for independently controlling the event markers 2 2 3 X Y Recorders The ability to easily plot one variable as a function of another is a valuable asset in any computation facility The X Y recorder is ideally suited to this application Responses as a function of time may also be obtained on the X Y recorder by driving the X axis amplifier with the output from an analog computer integrator which generates a linear ramp voltage waveform While most X Y recorders also offer a built in time base for sweeping the X axis for plots as a function of time it is often mor
41. loating Point Processors Data Storage Devices Disks DECtape Magnetic Tape User Interface LA30 DECwriter VT52 Video Display HP2640A Interactive Display Terminals vT05 Alphanumeric Video Display Data Output Device Interprocessor Links GA N gt See P QN P VG d P d P P S P Pp P PD P gt P P P C9 CO CJ CJ GJ IN tO I2 IH P EP Page 444 16 18 19 20 21 22 44 TABLE OF CONTENTS continued SOFTWARE 5 1 IAS Executive 5 2 DECNET IAS 5 3 Language Processors 5 4 Hybrid Software 5 5 Utility Programs 5 6 Documentation Aids 5 7 Maintenance Programs SYSTEM UTILIZATION AND RELIABILITY ACKNOWLEDGMENTS REFERENCES 51 51 FIGURE FIGURE FIGURE FIGURE FIGURE FIGURE FIGURE FIGURE iiil LIST OF FIGURES Functional Diagram of the Dynamic Analysis Facility One of Two AD FIVE Analog Computers An AD FIVE Patchboard One of Two Display Racks Block Diagram of the Hybrid Computer The PDP 11 45 Computer The PDP 11 55 Computer Data Paths of the Central Processor 13 17 24 26 27 1 INTRODUCTION The Reactor Control Branch at the Chalk River Nuclear Laboratories CRNL is engaged in the development of dyramic analyses and design and control techniques required for the definition of control and safety system strategies for advanced CANDU power plants and related nuclear systems To perform this task compute
42. or a memory management unit and a UNIBUS priority arbitration unit see Figure 8 e mH Ei 5 n i gt e a e H E FIGURE 7 397 5 UNIBUS ARBITRATION UNIT MEMORY MANAGEMENT LOGICAL UNIT PROCESSOR REGISTERS FIGURE 8 DATA PATHS OF THE CENTRAL PROCESSOR 28 The general purpose registers are used as accumu lators index registers auto increment and auto decrement registers and as stack pointers for temporary storage of data Conventional 16 bit computers have memory reference instructions operate or accumulator control instructions and I O instructions The PDP 11 computer is different from other mini computers in that all operations are accomplished with one set of instructions Peripheral device registers can be mani pulated as flexibly as core memory by the central processor and most instructions that operate on CPU registers can also operate on memory or peripheral registers The arithmetic and logic processor contains logic for a wide range of operations such as high speed fixed point arithmetic with hardware multiply and divide and extensive test and branch operations The memory management unit provides the hardware necessary for complete memory management and protection It provides the means for assigning memory pages to a user program and preventing that user from inadvertently making any access to pages outside
43. puter via a master slave relationship For inter console communication there are 110 analog signal trunks 55 of which are addressable and 20 logic trunks However 10 logic trunks become dedicated when the machines are slaved 2 1 The AD FIVE Mainframe An AD FIVE console is shown in Figure 2 The operator control panel logic control panel with indicators digital access panel and analog overload indicator panel comprise the left quarter of the machine The patchboard and computing elements occupy the centre while 120 digital coefficient units are in the right cabinet The patchboard is divided vertically into two fie ds each field having an upper logic section and upper and lower analog sections Each field has six areas which extend hori zontally for six patchboard holes per area and vertically through all three sections logic and upper and lower analog Each area has components clearly labelled and numbered see Figure 3 FIGURE 2 ONE OF TWO AD FIVE ANALOG COMPUTERS CONSOLE I A PP L I E D DYNAMICS FIVE eee He FIGURE 3 AN AD FIVE PATCHBOARD 2 1 1 Logic Components One third of the AD FIVE patchboard is dedicated to logic computing components Each console has the following complement of logic components l6 comparators 8 double pole double throw function relays 48 flip flops 60 logic gates two decade binary coded decimal counters logic switches interval timer reference timer
44. r facilities are required on which to develop detailed dynamic models Some of the desirable features of such facilities are 1 real time simulation implying high speed of compu tation good man machine interaction i e rapid solution turnaround ability to accept process hardware e g a process control computer ease of programming good computational accuracy A real time simulation is one in which the various models duplicate the dynamic events that occur in the real System on the same time scale Thus real time simulation gives the analyst a feel for the dynamics of the system being studied Analog computers are well suited for this type of simulation because they can solve coupled mathematical equations in parallel and continuously in time whereas digital computers perform mathematical operations serially in discrete time steps The analyst must be able to repeat solutions rapidly to explore efficiently the effect of parameter changes while developing and learning to control a model This is defined as good man machine interacticn and is also easy to achieve on an analog computer For some simulations it is desirable to connect certain reactor and process instrumentation directly to the models A typical example is a process control computer connected to a detailed CANDU power plant simulation Here real time simulation is mandatory since to develop realistic control algorithms the model represent
45. r the HIF RIF path or the analog control panel DACs have three possible methods for transferring the data in their initial buffer to their final buffer This data transfer or updating can be done in the following ways i Immediate update the new setting is immediately entered into the final buffer ii Digital update all DACs whose addresses have been stored for digital update are updated when the command is given from the digital computer iii Patchboard update all DACs whose addresses have been stored for patchboard update are updated when a logic pulse is applied to the UPDAC hole in the patchboard Digital and patchboard update are methods to eliminate time skew in digital to analog converters All sixteen DACs may be simultaneously updated either by digital or patchboard update 4 DIGITAL HARDWARF Presently there are two digital computers in the Dynamic Analysis Facility One computer a DEC PDP 11 45 is the digital processor for the Program Development System while the other a DEC PDP 11 55 is the digital processor for the Hybrid Computer Initially when the Hybrid Computer was installed in 1975 March the digital processor was the PDP 11 45 After two years experience with this system it was found that this computer was not fast enough to service the interrupts from the analog consoles for the function generation routines and permit program development to continue when these routines w
46. r will control up to 8 RK05 DECpack disk drives The DECpack disk cartridge capacity is 1 2 million words and the maximum transfer rate is 90 250 words s with an average access time of 70 ms All data transfers to from the disk utilize a direct memory access DMA interface The two disk systems are utilized in the following manner i The DIVA disk system acts as 3 DEC RP02 disks each with a capacity of 10 million words One RP02 holds the executive system and maintenance programs another holds the user and data files and the third is used as a scratch disk ii System and maintenance programs are supplied on RK05 DECpacks and the RK05 disk drive labelled C is used for transferring these programs to the CDC disk pack 33 The moving head disk system 18 in the Hybrid Computer is similar to that described above i e it consists of a RK11 controller two RK05 DECpack disk drives and two removable disk cartridges Of the two disk drives A holds a DECpack containing the executive system and maintenance programs while B holds a DECpack containing all the user files and data 4 2 2 DECtape The DECtape system 18 includes a 11 dual trans port controller a TU56 dual transport and two DECtape magnetic tapes The 11 controller will control up to four dual transports The diameter of the DECtape magnetic tape reel is 9 9 cm 3 9 inches and the reel contains 79 m 260 ft of tape with a capacity of 147 968 16
47. rd every 400 ns 4 1 2 Real Time Clocks The KW11 L clock 18 in the PDP 11 45 digital computer divides time into 16 2 3 ms intervals This clock is used by the IAS executive for timing purposes The KW11 P clock 18 in the PDP 11 55 digital com puter provides programmed real time interval interrupts and interval counting in 3 modes of operation Two crystal controlled signals of 100 kHz and 10 kHz can be used to clock a 16 bit counter Two external clock inputs i e a 60 Hz line frequency or an external clock input signal may also be used The counter may be counted up or down and can be read while in operation The interrupt sequence is initiated at 30 zero underflow during a count down from a preset interval count The count up mode is used to count external events An interrupt is initiated at zero overflow The programmable real time clock is used to synchronize real time events and to detect a time out of critical computing loops 4 1 3 Multi Device Buik Storage Bootstrap Loaders A bootstrap loader is a program that loads another program into computer memory from a peripheral device and initiates its execution The M9301 YB unit 19 in the PDP 11 45 digital com puter has 512 words of read only memory containing basic CPU and memory diagnostics a console emulator program and a specific set of bootstrap programs The following storage devices can be booted RXK11 diskette 11 cassette 11
48. riteria of pro gramming ease and good man machine interaction mentioned in the Introduction Software is required to allow communication between the Program Development System and the Hybrid Computer and DECNET IAS fills this role It offers task to task communica tions network file transfer and network resource sharing capabilities This section describes the software and how it meets the above criteria Documentation of programs and maintenance of hardware are important functions of any computing system Therefore documentation aids and maintenance programs are also reviewed 5 1 IAS Executive The IAS V3 0 executive 24 is called disk based because of the following important functions of the disk 39 A back up copy of the executive is stored on disk to permit system restart All tasks are stored on disk as core images prior to execution Libraries of subroutines used in tasks are stored on disk Files of any kind may be stored on disk and on other mass storage devices The executive is defined as priority ordered and Significant event driven because it performs a scan of the priority ordered active task list ATL when a significant event occurs By examining the status of the tasks in descend ing priority order the executive determines the next task to be initiated or continued The following cause a significant event I O initialization or queueing of I O normal I O completion reques
49. sets up and checks the analog computer iv The MCR Indirect File Processor 36 is used for interpreting commands from a file This processor reads the command file and interprets 47 each command Line either as a command to be passed to the MCR or as a request for action by the processor itself v A FORTRAN IV PLUS OTS 37 shareable library was built and is available to the users vi The Task Builder TKB 38 links the user s object modules resolves any references to shareable global areas and produces a single task image which is ready for installation and execution vii The TECO editor 39 is a character oriented editor viii The Librarian Utility Program LBR 34 aliows for the creation updating modification listing and maintenance of object and MACRO library files A library file s a direct access file containing one or more modules of the same module type Library files are organized for rapid access by the Task Builder and MACRO 11 assembler ix The Device Unserviceable Documentor DUD 40 is a program that allows the users to log hardware and Software complaints and to recall complaints that bave been encountered by others but have not yet been resolved x MCR Command Utilities 41 are a group of command files that provide a generalized compile task build and run capabi ity These command files are processed by the MCR Indirect File Processor The following utilities are available on
50. single precision add and subtract 4 6 us multiply 6 6 us divide 10 0 us double precision add and subtract 6 2 us multiply 12 0 us divide 18 4 us single or double precision 32 or 64 bit floating point modes same types of addressing as CPU instructions six 64 bit floating point accumulators used in numeric calculations and interaccumulator data transfers error recovery aids i e each error causes a trap The floating point processor model 11 17 in the PDP 11 55 digital computer has the same features as the FPll B processor above except that it is faster i e single precision add and subtract 1 65 us multiply 3 27 us divide 4 29 us 39 s double precision add and subtract 1 68 us multiply 5 43 us divide 6 73 us 4 2 Data Storage Devices 4 2 1 Disks The Program Development Facility has two disk systems the DIVA model DD 54 and the DEC RK11 The DIVA model consists of a DIVA COMPUTROLLER V controller a CDC 9762 disk drive and a removable CDC 9877 disk pack The COMPUTROLLER V controller will control up to 8 CDC 9762 disk drives The CDC 9877 disk pack has a formatted data capacity of 34 7 million words and the maximum transfer rate is 604K words s at an average access time of 30 ms All data transfers to from the disk utilize a direct memory access DMA interface The RK11 disk system consists of an RK11 controller one RK05 DECpack disk drive and one removable disk cartridge The RK11 controlle
51. t for task execution scheduling of a task to be run in the future a mark time directive a resume directive task completion declaration of a significant event Multiprogramming of tasks is provided by assigning a software priority level 1 250 to each task This allows interruption of a lower priority task when a higher priority task requires the CPU resources Event flags are provided to allow the individual task to control its execution and to allow communication with other tasks and the operating system The IAS executive is a partitioned system Parti tions are named contiguous blocks of memory the number of which is fixed during system generation All tasks in all partitions can execute in parallel and partitions are either user or system controlled A user controlled partition can accommodate only one task at a time while a system controlled partition can accommodate as many tasks as can fit into the defined physical space The basic program unit executing under IAS control is a task consisting of a program module or a set of program modules Program modules are linked to each other and to the Operating system by an overlay task builder and are stored on disk in absolute image form Task execution can be invoked by other tasks or by a terminal user Tasks can be specified to execute in an indicated memory partition at a given priority under an indicated User Idencification Code only
52. the PDP 11 45 digital computer In this report we describe the functions of the various hardware components of the present Dynamic Analysis Facility shown schematically in Figure 1 and the interactions between them A brief description of the software available to the user is also given 2 ANALOG COMPUTER HARDWARE The objective of simulation is the solution of man s mathematical approximation of nature namely differential equations in the most efficient and accurate way possible Analog computers are very flexible tools for the solution of sets of differential equations because they offer true parellel processing which can yield many solutions per second The high computational speed and flexibility of the analog computer permits many dynamic processes and systems to be simulated in real time faster than real time or slower than real time as appropriate This property of the analog computer leads to excellent man machine interaction whereby an analyst can develop a feel for his problem which often results in a more rapid solution or optimization of a problem Because the analog computer uses voltages to represent problem variables it is relatively easy to add standard process control hardware to a simulation Also the simulation Of a small part of a process system may be connected directly to the actual system for evaluation of its behaviour Modern analog computers contain in addition to the standard analog computing
53. the Program Development System only i The File Transfer Program FLX 34 is a file utility program that performs file conversion between DOS 11 or RT 11 and FILES 11 format ii iii iv v vi vii viii 5 6 48 The Scientific Subroutine Package 42 is a collec tion of more than 100 FORTRAN subroutines which pro vide the user with a large cross section of commonly used mathematical and statistical routines The GRAPHIC package 43 is a set of subroutines that simplify the use of the Versatec printer plotter for plotting results The NDCU routine 44 is used to convert a patchboard hole number into a hybrid address MTRW 45 is a subroutine for convenient use of magnetic tape from FORTRAN FFTSC 46 is a subroutine that performs a radix 2 fast Fourier transform A forward or inverse trans form as well as a power spectrum may be calculated HPXFR 47 is a program used to transfer data between the HP9820A calculator and the PDP 11 45 digital computer The Dynamic Analysis Facility Versaplot Package 48 is the original Versaplot II version 06 package with enhancements to make it more convenient to the user The Versaplot Package utilizes a two phase plotting technique In the first phase the entire plot image is generated in vector data The vector data are converted in the second phase to raster form for plotting Documentation Aids One of the major responsibilities of an
54. vember B Switzer and C B Lawrence AECL internal files Chalk River 1975 December System 511 Hybrid User s Manual Volume 2 Chapter 4 Applied Dynamics International Ann Arbor Michigan RSX 11 Utilities Procedures Manual AA 5567B TC Digital Equipment Corporation Maynard Massachusetts 1977 January C J Barker and C B Lawrence AECL internal files Chalk River 1976 October D 3 Argue AECL internal files Chalk River 1977 December D S Argue AECL internal files Chalk River 1977 September 38 39 40 41 42 43 44 45 46 47 48 49 50 51 55 IAS Task Builder Reference Manual AA 2533C TC Digital Equipment Corporation Maynard Massachusetts 1978 October D S Argue AECL internal files Chalk River 1977 March D S Argue and W T Howatt AECL internal files Chalk River P D McMorran AECL internal files Chalk River RT 11 Fortran Scientific Subroutine Package Reference Manual DEC 11 ARSMA A D Digital Equipment Corporation Maynard Massachusetts 1975 P D McMorran AECL internal files Chalk River 1977 June P D McMorran AECL internal files Chalk River 1977 September P D McMorran AECL internal files Chalk River 1977 September C B Lawrence AECL internal files Chalk River 1977 November D S Argue and W T Howatt AECL internal files Chalk River C J Barker and C B Lawrence AECL internal files Chalk R
55. y programmer is the documentation of his work To aid the user in this task the following programs have been purchased or written by the system personnel and are available on the Program Development System i RUNOFF 49 is a program to facilitate the prepara tion of typed or printed manuscripts 49 ii The Hewlett Packard Editor HPE 50 is a program that operates with the IAS executive to support the block mode editing capability of the Hewlett Packard model 2640A terminal iii The Hewlett Packard printer HPP 50 is a program used with the IAS executive to print the character code generated by a Hewlett Packard terminal model 2640A iv LST 51 is used to format listings for documentation It provides a standard header and adequate margins on all sides v EXTRAC 51 is an MCR command file that extracts a brief user s guide from the comments of a source program 5 7 Maintenance Programs Digital Equipment Corporation DEC supplies main tenance programs to test individual components and peripherals of the PDP 11 digital processors Also supplied by DEC is a system exerciser program that exercises all the components and peripherals of the PDP 11 system This exerciser is run on both digital computers during non working hours By leav ing the processor power on and using this exerciser the number of failures of the digital processor and peripherals has greatly decreased The communication pat
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