Nikolay Petrovich Brusentsov

José Ramil Alvarez

Ternary Computers: The Setun and the Setun 70

Keywords: Ternary computer, trit, tryte, Setun, DSSP, Nastavnik

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

At the beginning of 1956, the department of electronics came into being at the computer center of Moscow State University (MSU) through the initiative of S.L. Sobolev, a member of the Russian Academy of Science. At the time, Sobolev was the head of the department of calculating mathematics at the mechanical and mathematical faculty of MSU. He initiated a seminar with the aim of providing practical examples for a digital machine usable in universities, in laboratories, and in the design burros of industrial enterprises. It was necessary to create a small computer that was simple to use and master, that was reliable and inexpensive but at the same time was effective in solving a wide range of problems.

A detailed study had begun to determine the status of current computers and their technical abilities. This effort lased a year. The study led to a nonstandard decision to use in the created machine not the binary code but the ternary code. Twenty years later, Donald E. Knuth called this the -balanced‖ system of calculating and which -may be the most graceful‖ [START_REF] Knuth | Seminumerical algorithms‖[END_REF]. Claude E. Shannon revealed some of the advantages of this system in 1950 [START_REF] Shannon | Symmetrical notation for numbers‖[END_REF].

The common binary code used in modern computers has the digit set {0, 1}. Binary code does not contain arithmetical full value, as it is impossible to represent the negative numbers in it. However, a ternary code with a digit set {-1, 0, 1} provides optimal arithmetical values for numbers formation. Therefore, we not only an artificial and imperfect complement code of numbers, but we also obtain considerable arithmetical advantages. These include a uniform number code, a variable length of operands, a singular shift operation, a tri-value of a function's -sign of a number‖, an optimal rounding by simply cutting off lower digits, and a compensation of errors rounding in the process of calculating [START_REF] Brusentsov | Notes about ternary digital equipment‖, Architecture and Programming of Digital Systems[END_REF].

The Setun Computer

To address this new challenge, we had to create a new computer-a ternary computer-called the -Setun‖ as an experimental model [START_REF] Brusentsov | Computer ‗Setun' of MSU‖[END_REF][START_REF] Brusentsov | A small computer ‗Setun[END_REF]. By the end of 1958, we assembled and began to use the new machine with the collaborators of the electronics department. As we mastered the machine and gained more experience with the program facilities and the variable practical devices, it was obvious that the Setun computer met all requirements and all foreseen tasks intended by its creation.

This success showed the efficacy of the ternary digital machine, even taking into account that the creation of such equipment was the first of such machines completed by a small group of the beginners (eight graduate pupils from MEI and MSU, and twelve technicians and laboratory assistants) in short period of time. In comparison with the binary elements of memory and elementary operations, the ternary design made the architecture of computer more natural and simple.

Features of the Setun

With a minimum set of commands (only 24 single-address commands), the -Setun‖ provided an opportunity to do calculations with fixed-point and floating-point numbers. The machine had an index register, the value of which could modify an address by addition or subtraction. It also provided the addition operation with products that optimized polynomial calculations. It utilized three-valued (trit) operations for multiplying and three commands for conditional transition according to the sign of the result. The simple and effective architecture provided an opportunity to facilitate the computer with the programming system and a set of application programs [START_REF] Zhogolev | The Order Code and An Interpretative System for the SETUN Computer[END_REF] by a small group of programmers by the end of 1959. That was sufficient for interdepartmental testing of the experimental model by April of 1960.

According to the results of testing, the -Setun‖ computer became -the first working sample of a universal computer on the base of elements without lamps‖. The machine had the following characteristics: -high productivity, sufficient reliability, small forms, simple technical service‖. The Council of Ministers of the USSR made a resolution of the serial production of the -Setun‖ at the Kazan plant of mathematical computers by the recommendation of an interdepartmental committee of experts.

Production Dynamics

However, for reasons unknown, the officials from Radio Electronically Department did not like the ternary computer and they did not provide the serial production of the computer sample. When it received the opportunity to use the M-20 computer produced in the plant, it did not help the output progress. Notwithstanding, when the number of orders (particularly from abroad) for the Setun grew, they limited the output, which resulted in declining orders and by 1965, they stopped production. In addition, they prevented the mastering of the machine in the USSR where they planned a large production of the machine. The reason for such strange -politics‖ could have been the very low price of -Setun‖. It sold for only 27,500 rubles because of the perfect production of its magnetic digital elements at the Astrakhan plants EA and EP where it cost only 3 rubles and 50 kopeks for each element. (The machine had about 2 thousand elements.) It was essential that electromagnetic elements of the -Setun‖ accomplished the threshold realization of ternary logic that was truly economical, natural, and reliable. They destructed an experimental model that was in an absolute working state after seventeen years of continuous operation in the computer center of MSU. We changed only three elements with defects during the first year of operation and the machine did not need any repairs to the inner devices. The serial machines functioned well in different climatic zones from Odessa and Ashkhabad to Yakutsk and Krasnoyarsk without any service or spare parts.

Thanks to its simplicity, its natural architecture, and its rational constructed programming system, the Setun effectively used an interpretive system successfully. Some of its features included floating-point numbers with eight decimal digits (IP-2), floating-point numbers with six decimal digits (IP-3), complex numbers with eight decimal digits (IP-4), floating-point numbers with twelve decimal digits (IP-5), auto code -Poliz‖ with its operating system, and a library of standard programs that used floating-point numbers with six decimal digits.

Users at universities, industry enterprises, and the Scientific Researching Institute (SRI) well mastered the Setun computer. It became an effective tool for solving practical important problems in very different fields from scientific researching modeling and design calculating to weather forecasting and the optimization of enterprise management [START_REF] Brusentsov | Annotated guide of programs for ‗Setun[END_REF]. Users conducted many seminars on the Setun computer at MSU (1965), at the Ludinovskij locomotive building plant (1968), and at the Irkutsk Polytechnic Institute (1969). Dozens of reports emerged about the economic application of these computers. Thanks to its natural ternary symmetric code, the Setun appeared to be a real universal calculating device. It positively proved to be a technical research tool for computer mathematics in more than thirty universities. For the first time an automated system of computer-assisted instruction occurred at military air engineering academies base on the Setun [START_REF] Kuznezov | Materials on mathematical service of -Setun‖[END_REF].

Some Mathematical Details

The ternary system of calculating applies the same principle of number coding as applied in the binary system used in modern computers. However, the weight of the i-th position is not 2 i , but 3 i . The positions themselves are not two-valued (bits), but three-valued (trits); that is, in addition to 0 and 1, there is a third value, which is 1, thanks to the uniformly represented by positive and negative numbers. We can calculate the value of an n-trit number similar to calculating the value of an n-bit number. That is,

n-1 N =   i 3 i =  n-1 3 n-1 +  n-2 3 n-2 + i 3 i +...+ 1 3 +  0 i=0
where  i {1, 0, 1} is a place value in the i-th position.

The symmetrical system of ternary numbers lends itself to use signs for place value coefficients; that is, instead of using 1, 0, 1, we can use +, 0, . For example, the decimal numbers 13, 7, 6, 6 in such a ternary record would have a representation by: o + + + for +13, o +  + for +7, o +  0 for +6, and o  + 0 for 6. The sign change of a number using the symmetrical code is equal to a ternary inversion; that is, interchange all -+‖ values into -‖ values and all -‖ values into -+‖ values. Using the above, the representation for 7 would be simply  + . The definition of addition and multiplying in the ternary symmetrical code appear in the tables below.

Add + 0 - + + - + 0 0 + 0 - - 0 - -+ Multiply + 0 - + + 0 - 0 0 0 0 - - 0 +
Unlike the binary code, this arithmetic of signed numbers and the sign of a number is the value of its higher position (not 0 or 1). Problems arising from signed numbers do not have a -perfect solution‖ in binary code. In the ternary symmetrical code, no such problem exists, which is its advantage.

We can characterize the Setun computer as having a single sequential address, with a 9-trit command code, an 18-trit register summarizer S and multiplier R, a 5-trit index register for address modification F, a pointer for fulfilling commands C, and a one-trit pointer of a result sign  that can regulate conventional transitions.

The operating memory contained 162, 9-trit cells divided into 3 pages with 54 cells per page for exchange with memory, and a magnetic drum having a size of 36 or 72 pages. Reading and recording into the operating memory occurs using either 18trit or 9-trit words; a 9-trit word corresponds to the older half of an 18-trit word appearing in the registers S and R. We interpret the content of these registers as fixed number after the second from older position's point; that is, according to module it is less than 4, 5. When calculating with a floating-point mantissa M of a normalized number, it must satisfy the condition that 0.5  M  1.5; the order appears as a separate 5-trit word interpreted as whole number with a sign. Page two-stage structure of a memory with word address in the range of three pages that has a 5-trit addresses and a 9-trit commands gave a unusual compact programs and at the same time high speed of the computer in spite of the fact that in interpreting systems magnet drum functions as an operating memory.

The Setun 70 Computer

Between 1967 and 1969, we created a ternary digital Setun 70 computer based on the experience and practical application of the Setun computer. An experimental model appeared in April of 1970. This computer contained a nontraditional two-stack architecture designed on the premise of providing good conditions for further expansion and development of its abilities by using an interpretive system method [START_REF] Brusentsov | Structure and algorithms of small computer functioning‖[END_REF].

The Setun 70 used an arithmetic stack (a stack of 18-trit operands) because of the Polish inversion writing program (-Poliz‖) used as a computer language; Poliz worked well on the Setun computer. The Poliz-program did not consist of commands of different addresses; instead, it used short word logic of 6-trit trytes. As an element of a program, we defined a tryte (the smallest addressable unit) for addressing or for operating. We used an addressing tryte as an operand or as an instruction to send an addressing word (one to three trytes) from the operating memory onto the operand stack. There were only nine pages with 81 trytes per page in the operating memory; for the access, we opened only three pages with their numbers in the -pointing registers‖. The operating tryte points the operations or procedures for the operands stack and the processor register. There are only 81 operations: 27 basic types, 27 auxiliary types, and 27 that are programmable by a user.

The second system stack had return addresses when processing breaks. The fulfillment of the program allowed the realization of E.W. Dijksta's idea of structured programming on the Setun 70. This allowed for an input call operation of a program, a call according to a condition, and a fulfillment of a program cycle. As a result, the machine confirmed that procedural structured programming highlighted the advantages of Dijksta's method; that is, the difficulty of creating programs became five to seven times less, thanks to the traditional testing -arrangement‖ on examples we used. Moreover, the programs became more reliable, logical, understandable, and easily modifiable. In addition, the peculiarities of the Setun 70 became a basis for dialogue system of the structured programming DSSP that was accomplished on the DVK type computers and on personal computers [START_REF] Brusentsov | Dialogue system of structured programming‖[END_REF][START_REF] Brusentsov | Developing adapting language of a dialogue system of programming‖[END_REF].

5

The Setun 70 and the "Nastavnik"

Unfortunately, administrative decisions stopped the further development of the abilities of the Setun 70 computer and its programming capabilities. We had to change our focus toward the study of computerization. The Setun 70 became the basis for development and fulfillment of automated computer systems for the teaching of -Nastavnik‖ [START_REF] Brusentsov | Automated system teaching ‗Nastavnik[END_REF][START_REF] Brusentsov | Microcomputer system teaching ‗Nastavnik[END_REF] that contained the principles of Y.A. Kamenskij's -Great Didactics‖. The purpose of the computer in this system was not the -electron turning over pages‖ and multimedia effects; instead, it checked the students' understanding of what they were studying in an attempt to overcome misunderstandings and providing with real subject skills by exercises. In addition, the computer would record the lesson itself giving the creator the opportunity to evaluate the effectiveness of using didactics methods and to modify the material and improve them.

Studying materials in -Nastavnik‖ appeared in typed form with numbered sections, passages, exercises, and notice of wrong answers. Thanks to the Setun 70, the computer was able to interact with a student rather easily. It gave the -book‖ the ability of communicating with a reader with the help of simple terminal with digital keyboard, and calculating indicator. The creation of study materials for the -Nastavnik‖ was not associated with computer programming; in practice, it showed that schoolteachers could create materials in mathematics, physics, English, and other subjects. The didactic effectiveness of the system was very high. For example, for the course in -Basic Fortran‖, students of MSU studied on the -Nastavnik‖ for ten to fifteen hours, students from the economics department for fifteen to twenty hours. The results showed that students using the computer had better programming skills in Fortran than those studying a usual semester course on the subject.

The principle of using a -book-computer‖ in the -Nastavnik‖ provided an opportunity for optimal computer usage as a practical means for studying. In all respects, the Setun computer provided the necessary tool (microcomputers and connected with it, 30-40 terminals as a simple calculator) for automated learning; it was inexpensive, reliable, and easily mastered by students and teachers. The work in a regime of a dialogue was not difficult; in fact, it was fascinating and guaranteed quick and good mastering of a subject that had good material organization. The application system at MSU, MAI, VIA, in schools, and for professional studying at a plant proved its effectiveness in wide range of subjects and study levels. The -Nastavnik‖ functioned for thirty years for automatic testing and tests to identify the English language level of first year students to form groups according to levels.

Despite the great necessity to improve the process of studying in the -informative‖ twentieth century, the -Nastavnik‖ began to fall in disfavor. The reasons may include its low price, its simplicity, and the lack of a proper display, mouse, and hypertext. The fact remains that using information technologies in the process of studying elevates student learning according to the number of computers used and their power and not to their level and quality of teaching.


Olga Parakhina
email: parakhina@yandex.ru

Yuri Polak
email: yuripolak@yahoo.com

Teaching Computer Science in Moscow Universities: Evolution for Forty Years

Keywords: Computer education, history, hardware, information search

The authors share their experiences of teaching computer science at Moscow universities since early 1970s. During this period the technical basis, as well as content and methods of teaching have dramatically changed. The authors state that studying of modern information technologies promotes the creative development of students; and the best way to prepare students

Early Period of Computer Education

Education is critical to each citizen's ability to thrive in the knowledge economy. Today's students must develop key 21st century skills such as familiarity with problem solving, critical thinking and collaboration, and especially information and communication technology. But still half a century ago there were no preconditions for mass training to these disciplines. The quantity of computers was insignificant, they were bulky and expensive, and only skilled experts could communicate with them, using language of machine codes.

Authors (at least one of them) were taught programming since early 60s. Computer training of schoolchildren was spent then only in few special schools and special workshops in some colleges. As early as in 1960 the first graduation of schoolboys with qualification 'programmer' in the Moscow school #444 took place. First generation computers on electronic lamps ('Ural-1', M-20, 'Elliott') formed a technical base of training. The general-purpose electronic digital computer 'Ural-1' was manufactured in Penza in [1955][1956][1957][1958][1959][1960][1961]. It was designed for solving factory planning; accounting, statistical and other problems. Some of its characteristics appear in Table 1.

During training, schoolchildren carried out various educational tasks, e.g. solving systems of linear equations, matrix operations, functions tabulation etc. Later, during education in the Moscow State University (late 1960th-1970th) authors were engaged in developing algorithms and programming on Algol language. After graduation from the University authors have been conducting pedagogical work in several Moscow colleges and universities (MGAPI/VZMI, MGIU/VTUZ-ZIL, MIREA, MESI, MATI etc) using various Soviet-made computers ('Dnepr', 'Minsk', 'Nairi', ES-1020 etc) and different programming languages (Algol, Cobol, Fortran, PL/1, YaAP). That time computer science education everywhere occurred without direct contact between trainees and computers as training system based on batch mode principles. Students gave blanks with texts of programs to their teacher and (after card punching) received results of its performance in a few days in the form of paper listings. Debugging procedure required repeating these operations again and again. Prior to the beginning of 1980th training to computer science was conducted only in natural-science, technical and economic colleges and universities. The basic disciplines were programming and algorithmic languages (usually Algol, Fortran or PL/1). That time computer literacy was understood exclusively as skill to programming. Educational process had met a number of difficulties because of some problems (and not all of them are solved till this time). First one was the poor technical equipment. In the majority of educational institutions teaching of computer science was carried out then without any computers (there was a popular joke: teacher distributed clay to schoolboys and asked them to mould a computer). Secondly, that is not less important, lack of the qualified teachers, especially in secondary schools. At best, teachers of physics or mathematics taught computer science at schools. Therefore the learning efficiency was enough low.

Back to Dialogue

Computers have been separated from trainees for years. This situation was changed radically after arising of terminal classes for mainframes and especially desktop microcomputers. The opportunity of dialogue between student and machine has introduced absolutely new qualities into educational process. Acceleration of program debugging and controlling any stages of computational process became possible. Students' understanding of computer functioning had improved, and their interest to lessons had grown [START_REF] Polak | Computerization of Education: Problems of Mass Learning[END_REF].

However, the technical equipment for these lessons remained outdated and inefficient. Soviet Union has catastrophically lagged behind the West in computer science and high technology, especially in telecommunication and microprocessor equipment. Some reasons promoted it, but the main were ideological and economic reasons. For many years in the USSR, there was a strict control over information dissemination and any printing or copying equipment. Authorities felt the latent threat in the idea of a personal computer, which assumed information freedom and human development. From the other hand, Soviet economy was extremely nonflexible because of state regulation, and USSR could not quickly organize manufacturing of personal computers. During 'cold war' import of many necessary components was impossible because of COCOM restrictions, so 'Motorola 68000' processor was under strict embargo.

That's why teachers of CS were compelled to use unproductive and inconvenient domestic computers. But even their amount was too far from real needs. For instance, 'Electronics D3-28' which was the main training means in MIPT, MADI, VZMI and other institutes in the beginning of 1980th, was made at three plants in total not more than 5000 / year. We remember our expectations within many months in queues of potential users directly at plants, so it was difficult for us to equip classes; it took 5 years to buy 60 computers (and monitors for them from other plant). But even such imperfect equipment has allowed to introduce dialogue methods and BASIC language into educational process. The 'D3-28' characteristics appear in Table 2. In higher education that period teaching of computer science had extended to humanitarian disciplines, but programming still remained as a main content of education. In 1990th intensive distribution IBM PC in Russia had attracted noticeable changing the content of CS courses at all steps of education. As mass preparation of new equipment users was required, many colleges have made computer science an obligatory subject at all faculties. They finished to teach programming, having passed to IT-training. The motto 'programming is the second literacy' was replaced with the new purpose, 'mass computer literacy'.

Besides hardware, huge changes in the agenda of training courses, in principles of laboratory practical work organization took place. Chalk and cleaning cloth were replaced by felt-tip pens and markers, then notebooks and projectors. Now lectures are accompanied by multimedia demonstrations, and 1st rate students have skills of professional information search and use specialized software packages.

The higher education information infrastructure was improved as well. Federal university network RUNNet was created in 1994-96; followed by infrastructure for basic network for a science and education RBNet (1996-99). The same time Soros Foundation opened Internet-centers in 33 leading universities. Since 2000 the Federation of Internet Education created about 50 centers for training teachers to possess Internet-technologies. One more private initiative, Intel Teach to the Future Program, is a worldwide professional development effort to help teachers. Launched in 2000, the program has reached more than 3 million teachers in 30 countries (300 thousand in Russia). Through this free program, teachers learn from other teachers how, when and where to incorporate technology tools and resources into their lesson plans. Participants create assessment tools and align lessons with educational learning goals and standards.

Contemporary Problems of IT-Education

One of the main problems in IT-specialists training is a gap between plans of academic education and requirements to graduates, employed in companies. Colleges and universities curricula don't follow modern tendencies of branch, so companies should retrain their staff. It requires not less than half a year, or even 2-3 years for highly skilled employees' formation. In a number of universities there is nobody to teach the specialists of modern level, since many leading teachers and professors have retired, or left abroad, or work in other spheres, not according to their qualification. The average age of the faculty is close to 60 years, and their salary is less than underground cleaners' one.

The quantity of students becomes less as well. Alan Martinson has mentioned demography problems in his presentation during the Russian Outsourcing and Software Summit (ROSS-2006; http://www.soft-outsourcing.com). Here are some figures from his presentation. There are nearby 1.3 million people in the age of 17 in Russia now, but in ten years this quantity is to be decreased approximately up to 650 thousand person, and only then the curve should go upwards. According to Martinson, now Russian colleges graduate 40-50 thousand 'pure' IT-specialists annually, plus 200-250 thousand graduates have base knowledge in IT-technologies. But there are a number of new and actively demanded specializations where education in universities is not conducted at all, or the quantity of graduated experts is not enough. Among such specializations of scarce professionals are project managers; experts on testing; technical writers; manual developers; experts on interface ergonomics; analysts; experts on consulting and project implementation; and lawyers with IT-specialization.

One more essential feature of IT is the high speed of changes of applied technologies. The specialists should update their knowledge essentially at least every 5-6 years. Therefore it is necessary for Russian IT-education to establish close communication to labour market and to provide flexible reaction of education system to its inquiries, and also to develop system of lifelong education and personnel retraining. Russian IT-companies should play an important role in this process. They can help in definition of requirements to graduates knowledge and curricula; in launching the centers for additional and certificated training etc.

Many IT-firms actively cooperate with educational institutions, introducing joint programs of training the students of senior rates, so they are prepared for work in ITindustry on a student's bench. Computer business helps to introduce both the newest tendencies in the field of technologies and needs of branch into conservative curricula of higher education system. Here are some examples of such cooperation. The LANIT Company conducts joint activity with the Higher School of Economy, giving an opportunity to students to pass training, and teachers can raise their qualification on company's courses. One more project of LANIT is the computer school 'Expert' organized together with Computational Mathematics Faculty of Moscow State University. Undergraduates and post-graduate students of Moscow Institute for Physics and Technology can maintain their theses for master's degrees and Ph.D using their labour experience in the base company 'Phisicon'. In 2003 in the Nizhniy Novgorod University (under support of Intel Corporation) the Laboratory for Information technologies was created. Its mission is to form a stable system of education of highly skilled experts in modern computer technologies in view of IEEE-CS and ACM Computing Curricula recommendations for the enterprises of the information industry (naturally, for Intel as well).

In the St.-Petersburg State University chair of system programming is leaded by Prof. Andrew Terekhov who is a head of computer company 'Terkom' simultaneously. He considers that the best way to receive well-educated experts for the company is to train them necessary skills by himself. The teacher should be active researcher; he must tell students about his own research, instead of retelling another achievements. As Terekhov states, the cooperation between university and profile companies interested in carrying out of researches and students training is necessary. Such overlapping of practice and theory is successfully realized in St.-Petersburg State University. Education plans should correspond to international standards. Now only few Russian universities carry out requirements ACM/IEEE Computing Curricula (he estimates a level of his own university's conformity as 80 %).

The authors have similar experience as well. 10 years ago we have started to use students as researchers in real projects of Russian Academy of sciences. Simultaneously the CS curriculum in the Moscow State University has been modified in view of these practical problems.

As known, Internet has become not only communicative environment for scientific dialogue but also an invaluable source of information. Network technologies make researchers able to participate in international information exchange, while lack of Internet access rejects them to periphery of science. But sometimes unlucky searchers qualify Internet as 'information dump' (usually they ignore special tools and methods of effective search; don't use inquiries languages and search manuals; don't better their requests with additional keywords and so on). In Moscow State University we have developed a curriculum of computer science for sociologists with special attention to problems of network technologies and information search. Authors' course was changed dramatically four times for last 10 years. Each new version tries to meet the needs of the future research work and to approach the students to a level of competent users of the most widespread software. Now our course contains such sections as HTML documents, web design, etiquette of e-mail andlast but not least methods of information search in Internet.

Studying of modern information technologies promotes the creative development of students. Some of them confidently work with networks, cooperating with the elder researches in search and analysis of information sources for humanitarian disciplines. The best students not only well use the existent search mechanisms, but also actively participate in development of new ones. Since 1996, tens of students of Moscow State University were working in the Central Economics & Mathematics Institute (CEMI) of the Russian Academy of Science as junior researchers. They participated in support of one of the best directories of Russian Internet resources which was introduced in 1995 in the Laboratory for Network information resources of CEMI (founded by Dr Yuri Polak). Its development required researching the mechanisms of search and making many original decisions; in particular, a special taxonomy (hierarchical set of rubrics) was created. Since 1996 our directory is available online; its origin was our database with more than 50,000 annotated records of information resources grouped on 300+ themes, which described both Russian sites and also relevant foreign materials [START_REF] Polak | Internet in Russia, Russia in Internet[END_REF]. Besides the standard search programs were used for the database updating. The students of MSU had brought a significant contribution to development of this unique catalogue of Runet (Russian Internet) by supporting a database and monitoring the information resources. They took active part in checking URLs, writing annotations and reviews. Many thematic reviews prepared by the students were published in well-known professional editions such as bimonthly magazine 'Russia's Information Resources', non-periodical 'Russian Internet Navigator' and PC Week (Russian Edition).

Our collective had won a prize in competition of young researchers of Academy of Science on fundamental and applied researches. Our students have also developed a number of well-designed web-sites with rich content, including unofficial pages of psychological department flogiston.ru and sociological department www.nir.ru/socio/ of Moscow University. One more our project has been executed for the company Yandex, Russian portal #1. Its heart is a search engine with more than billion indexed documents of total volume about 30 TB. It has the largest database on Runet, vastly outstripping its nearest competitor. In early 2000s Yandex introduced a new advanced built-in catalogue. A group of MSU students took part in development of its taxonomies, database fulfilment and stuff training. The convergence of search engine and a catalogue allows overcoming their immanent defects: manually updated directories aren't enough full and actual; while the output of automatic search engine contains a lot of irrelevant links. This catalogue is structured specifically for the Russian market, showing web-sites based upon Yandex's 'Citation Index', a method of ranking web-resources by external references. This has proven very popular and the catalogue has quickly gained market share from the competition.

The amount and variety of Internet resources lead to complex taxonomies of universal Internet directories. As a possible solution to the problem, in Yandex catalogue a faceted classification was used. Facet analysis was developed as a tool for the organization of document collections in technical, scientific and social scientific fields, where it was highly effective in the storage and retrieval. Currently, facet analysis is used primarily to create classifications for the physical arrangement of documents (or document surrogates). In Yandex built-in directory such facets as 'genre', 'geographical region', 'source of information' and so on are used, so the search process become quicker and its results are more relevant.

The work in network environment expands mental outlook of the students, reduces time needed for fulfilment educational tasks, supplies them with unique information, improves their knowledge of foreign languages. Choosing the optimum decision of a search task, the students are being trained in network technologies and logical thought; develop their skills of information processing. These skills are necessary for their further research work and other activities [START_REF] Polak | Information search in Russian Internet on the eve of[END_REF][START_REF] Polak | Network technologies and creative development of students[END_REF][START_REF] Parakhina | Competitive and Game Components in Teaching Search Strategies[END_REF].

We do not know how the world of information technologies will change in seven to ten years. However, we are sure that this progress will noticeably change our life and, as consequence, educational curricula. We will wait these new challenges with great interest and try to meet it adequately.

Fig. 2 . 2 3

 22 Fig. 2. The class of 'D3-28' computers; 1980 2

Table

Table 2 .

 2 D3-28 Characteristics

Source: http://schools.keldysh.ru/sch444/01-04.htm


Vladislav P Shirikov
email: shirikov@jinr.ru

Distributed Systems for Data Handling

Keywords: Data handling, distributed computing, GRID

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

The creation and use of distributed systems for computerized accumulation, transmissions, and information processing in interests of scientific research started less than fifty years ago. Apparently, the first such system in Soviet Union occurred in 1961 for radio-channel transmission of Atlantic Ocean objects information to first Soviet semiconductor universal computer DNEPR in the Institute "Cybernetics" (Ukrainian Academy of Science) in Kiev. Basic realizations of multicomputer complexes for distributed jobs and data handling started in 1960s and the 1970s practically in all prominent research organizations in Soviet Union and abroad.

At the "top of success" of their development, we would have Grid systems in the nearest future; that is, complexes that correspond to three criteria according to the definition of one of Grid technology's ideologists, Ian Foster. He states [START_REF] Foster | What is the Grid? A Three Point Checklist[END_REF]:

" The Grid is a system that:

-coordinates resources that are not subject to centralized control … -using standard, open, general-purpose protocols and interfaces … -to deliver nontrivial qualities of service, relating for example, to response time, throughput, availability, security and/or co-allocation of multiple resource types to meet complex user demands, so that the utility of the combined system is significantly greater than that of the sum of its parts."

As an ideal, such a Grid system permits the ordinary user to input his/her job for batch or interactive processing without the necessity to define the job's "passport" (JDL-file) via attribute requirements. This includes the address of certain computer computing elements (CEs) as part of computing Grid resources. This is true if the system`s middleware has high-level services such as resource brokers (RB) and many of CEs, as it is now in large-scaled realized projects such as Enabling Grids for E-sciencE (EGEE). For example, see http://lcg.web.cern.ch/LCG/ and http://egee-jra1.web.cern.ch; however, there is no such service in the American Open Science Grid (OSG) project. We talk about distributed systems of twentieth century, but it is necessary to say that many ideas realized in contemporary Grid structured were not quite unknown to specialists, which created systems more than thirty years ago, as it will be shown below. In other words, it is possible to say, that the Grid is the realization of "old" ideas based on new technologies.

Early Activities at JINR

At such a physical scientific centre in the Russian territory, as the Joint Institute for Nuclear Research (JINR), which was organized in 1956 and closely collaborated with Western physical centers, especially with European Centre for Nuclear Research (CERN, Geneva), problems arose. These situations demanded a common approach for applications realization and matched software environment in computing servers; this would make easier for the data and the programs to exchange at least with use of magnetic tapes in time of direct computer links absence. As to main type of processed information, then at JINR, CERN and other centers (e.g. Brookhaven, Berkeley, and Daresbury), this was a large amount of experimental data from accelerators detectors. At JINR, which also carried out theoretical and experimental research in fields of low and intermediate energy physics, it was necessary, in particular, to register and process data taken from spectrometers in experiments with the use of a fast neutron pulsed reactor.

According to these application problems, one of main tasks of the 1960s and later was the technical and software support of a whole sequence of measuring, preliminary and final data processing for different fields of experimental physics and also for theoretical physics. The chosen method to resolve this task was essential. It was necessary to start building distributed multileveled computing complexes with the use of perspective and standard measuring equipment and standardized programming tools for applications (such as compilers for high-level languages as FORTRAN. The tools had to be compatible with Western versions of program libraries for universal and special destinations including programming tools for algorithms parallelization and tools for user access to computing resources of different types. Main tasks at JINR, mentioned below, were initiated and guided (through July of 1989) by a corresponding member of the Academy of Science (USSR) N.N. Govorun, the chief of mathematical division in the JINR Computing Centre (1963)(1964)(1965)(1966), vice-director and director (1988)(1989) of Laboratory of Computing Technique and Automation (LCTA).

The first stage of distributed systems creation started at JINR in 1962, when the simple structure of two connected by cable computers M-20 and KIEV in JINR Computing Centre could collect (via cable also) and process information from spectrum analyzer, located in measuring centre of Neutron Physics Laboratory shown in Figure 1. They also processed the punched paper tapes with information, prepared with use of special measuring devices, where the events, which happened in accelerator detectors and automatically photographed (in High Energy Physics Laboratory), were preliminary processed by operators. In 1965, this structure was modernized; they mounted an additional M-20 and they replaced the KIEV, which was not reliable, by the MINSK-22. They also used this structure for batch processing jobs in other fields of research. Its schema looked like the graphical presentation shown in Figure 2.

Late 1960s and Early 1970s Activities

From 1966 to 1974 saw the realization of the first stage of the three-leveled complex according to general principles and conditions (in addition to typical modern, up-todate distributed systems for physics). The principles provide:

1. Meeting the requirements of online experiments; 2. Remote batch and interactive processing for jobs; 3. Interactive mode for users and their terminals; 4. Algorithm parallelism with use of different computing elements in complex; 5. Maintenance of archives for programs and data.

The realization of this set of services was defined at JINR by the appearance of a sizeable set of new computers. These included:

o "small" computers (first level) for on-line experiments (equipment control and data registration) or remote input/output stations (RIOS), used for batch processing support; o "middle" computers (second level) for preliminary processing of data, taken from first level, and also for RIOS regime support; and o "large" computers (third level) as basic computing servers. This new set included some TPA (Hungarian production) computers, SM-3/4, M-6000 (analog HP-2116B), original HP-2116Bs, BESM-3M and BESM-4, MINSK-2/22, CDC-1604A, and the BESM-6. The BESM-6 started to be used as a basic computing server not only at JINR, but also in all noted scientific Soviet organizations. In fact, it was necessary to develop a preliminary software system. This is the reason the" DUBNA" appeared as a multi-language system with FORTRAN and other compilers and a programming library that was compatible with CERN library [START_REF] Shirikov | Matematicheskoye obespechenie vychislitel`nyh kompleksov i setei[END_REF][START_REF] Apokin | The Development of Electronic Computers in the USSR[END_REF][START_REF] Shirikov | Scientific Computer Networks in the Soviet Union[END_REF].

Another problem concerned the necessity to develop technical and corresponding software tools in BESM-6 operating system (OS) for connectivity with various local external devices and other computers of first and second levels. As a result, at JINR they modernized the BESM-6's peripheral control unit and new version of the operating system started to serve eight fast cabled lines. The lines had speeds up to 500 Kbyte/sec per line and up to 4 abonents connected to each line. In particular, they deployed remote data processing computers and RIOSes (also called "FORTRAN Stations" or FS) equipped with their own peripheral devices such as magnetic tape units, card readers, printers and terminals.

As far as the "middle" computers in laboratories are concerned, measuring centers had to participate interactively for information processing together with the BESM-6 with special "algorithm parallelism" tools. This is the reason to include a special "extracode" facility to serve external links embedded in the OS of the BESM-6. Additionally, they added subroutines to the DUBNA monitoring system that used this extracode useful in calling FORTRAN-written programs. Use of external interruption apparatus in the BESM-6 and peripheral computers (such as the BESM-4 that also used an analog of the FORTRAN-oriented monitoring system) helped to realize an analog of a modern Message Passing Interface (MPI) service. The schema of the complex in 1974 appears in Figure 3, where the CDC-6200 was added in 1972 as a BESM-6 partner on level 3 of the whole complex. In principle, the complex systems at JINR and the aforementioned systems had some similar features. For example, at CERN in system FOCUS, there existed concentrator (CDC-3200) for lines to servers CDC-6500/6400 (four cabled lines, up to 1Mbyte/sec and four peripheral computing or measuring abonents per line), RIOS stations, a terminal concentrator, and other peripherals. However, life was easier for Western scientific centers because there was no need for them to create for themselves the software environment as mentioned above. Regarding the type of computing servers, physicists in West always preferred to use 60-bit processor techniques for high-precise complicated calculations. This is why they used IBM computers for data registration and CDC serial 6000/7000 for processing and other calculations. Such computers were under embargo in the 1960s, but even the 48-bit BESM-6 was good enough.

It is necessary to mention that Grid started with the use of 32-bit technique in clusters, but the appearance of the 64-bit AMD and Itanium 2 processors immediately initiated the use of new PC-clusters in scientific centers. Hence, already by 2003, for the CERN "Openlab" project [START_REF]The CERN openlab: a novel testbed for the Grid[END_REF], several major physics software packages have been successfully ported on the 64-bit environment. For example, the Parallel ROOT Facility (PROOF) is a version of the popular CERN developed software ROOT for interactive analysis of large data files. In Russia, approximately at the same time, the Institute of Computing Mathematics in Moscow started to use a similar cluster with Myrinet 2000 bus for simulations, which earlier were based on use of access to the RAS Supercomputer Centre.

Late 1970s and Early 1980s Activities

In 1975 to the beginning of the 1980s at JINR, saw the installation of new ES-seria servers that were compatible with IBM-360/370; this led to the development of tools for terminal access to level 3 in computer complexes as shown in Figure 4. Alternatively, it used the ES-1060/1061/1066 microprogramed multiplexers. These ES-servers started to understand INTERCOM language by means of a process developed in LCTA software subsystem TERM. o Independent (of BESM-6, CDC-6000) service for terminals in the process of information receiving, editing, and archiving, when users prepared their job texts. o Execution of user directives (commands) to send a prepared job to a certain server (after automatically using the JDL-file edition) to show the status of jobs queues, to stop temporarily or kill a job in the server, or to print an output file on printer or terminal screen.

In principle, the concentrator could, in essence, execute functions, similar to functions of program services UI, NS and Resource Broker (RB) in modern Grid systems, especially if the user used a FORTRAN subset understood by all computing servers such as the BESM-6, the CDC, or the ES. The complex had the possibility to choose a server (this or that) simplified by the existence of compatible versions of library CERNLIB in the server's software.

Activities in the 1980s

The period 1983 to 1985 marked the starting point for the introduction of a standard means for the creation of local networks in scientific organizations and their external channels. Regarding local network structure and technology, the possible choices were the Token Ring/Token Passing or the then "young" Ethernet technologies. At JINR, they devised a local network in 1985. This was the JINET (Joint Institute NETwork) with a marker (token) method of access to a communication line of 12 km of 75-Ohm coaxial cable [START_REF] Shirikov | Scientific Computer Networks in the Soviet Union[END_REF]. The standard adapter nodes were connected to it in various JINR buildings; each node served eight to twelve serial (standard RS-232C) ports for terminals or computer multiplexer ports. About thirty adapters were bought from the Swiss firm Furrer-Gloor; they had built-in Z-80 microprocessors and built-in memories.

Afterwards, the engineers at JINR (our LCTA engineers) produced a set of their modernized analogs and they used them in the frames of JINET. The LCTA programmers at JINR completely produced the supporting software for all adapters, because the firm's software was too expensive. Moreover, we foresaw the possible modernizations and wished to have not only built-in binary software, but also source texts. This software supported virtual communication channels (communication sessions) according to a user's application through a common cable with a throughput of about 1 Mbit/sec.

Each abonent (terminal user or computer) could give various commands to his connection node such as calling the text editor in his node, checking status of different nodes and their ports, setting the suitable transmission speed at his port or defining the terminating symbols for messages (end of text line, of package if the defaults were inadequate. If no specification was necessary, the abonent simply commanded to establish a virtual channel for communication with the given address (e.g. node and port number or the other computer's symbolic name), started to use this channel and disconnected at the end of session. Abonents were like computers and they could exchange files using the standard KERMIT program. A special node-administrator or his "hot reserve" partner automatically controlled the marker's (token) movements, collected statistics of nodes connections and faults, recreated the lost markers, disconnected every other node in case of noticed frequent malfunctions.

In 1988, JINET became the abonent of international X.25 standard IASNET, being connected to its communication center in Moscow [START_REF] Shirikov | Scientific Computer Networks in the Soviet Union[END_REF]. This permitted to exchange files directly with physical centers, to use the telnet regime for access to certain servers; many JINR physicists had passwords for such access since they were members of different international collaborations. By the end of 1989, the standard JINR Ethernet was devised and connected to JINET as shown in Figure 5. It was time to dismount the BESM-6 and connect new servers to the Ethernet. A cluster of two VAX-8350 that contained shared disk memory (about 12 Gbyte), cartridge units (200 Mbyte), and high density (up to 6250 bit/inch) magnetic tape units. Additionally, the system contained the powerful MEGATEK/WIZZARD 7555 station with three-dimensional graphics.

Activities during the 1990s

At the very beginning of the 1990s, the throughput of the Russian terrestrial external channels was inadequate for territorially distributed information exchange and processing in high-energy physics, which had practical limits of 32K bits/sec. This is why two direct satellite channels were organized at JINR and started to be exploited in 1994 for access to the DFN (Germany) networks and the High Energy Physics NETwork (HEPNET) with an entry point in Italy and a terrestrial channel to CERN. The throughput of each channel was up to 64K bits/sec; we used our own antenna and the Soviet "RADUGA" satellite for first channel and the terrestrial link to a nearby Cosmic Communication Station "DUBNA" and international satellite INTELSAT for second channel. We had a plan to give some other Soviet scientific institutes such as the IHEP in Protvino the possibility to share this second channel with JINR. It description appears in [START_REF] Shirikov | Matematicheskoye obespechenie vychislitel`nyh kompleksov i setei[END_REF] and shown in Figure 6. Of course, terrestrial channels, with the same throughput as satellite channels, have an advantage in many cases and when new facilities to increase their throughput appeared (up to 1 Gbit/sec nowadays), we had taken the opportunity and ended the use of satellite channels.

Conclusion

In conclusion, we have seen some close perspectives in the use of distributed systems by a community of scientific organizations. They are, in particular, the final realization of an international project called the Worldwide LHC Computing Grid (WLCG) [START_REF]Collaboration in the Development and Exploitation of the Worldwide LHC Computing Grid[END_REF]

Figure 1 .

 1 Figure 1. Initial version of the JINR Grid

Figure 2 .

 2 Figure 2. Improved version of the JINR Grid

Figure 3 .

 3 Figure 3. Use of "middle" computers in the 1970s.

Figure 4 .

 4 Figure 4. Complex expansion using ES-servers

Figure 5 .

 5 Figure 5. Use of Ethernet connections at the end of the 1980s.

Figure 6 .

 6 Figure 6. Shared resources during the 1990s.

  . Eight institutions in the Russian Federation (in Moscow, Moscow district, St. Petersburg) became the participants in this project. The JINR Scientific Research Institute for Nuclear Physics of Moscow State University (SRINPofMSU), ITEP, IHEP, IAM, Research Scientific Centre of Kurchatov`s Institute (RSC KI), Petersburg`s Institute of Nuclear Physics (PINP) and the Institute of Mathematical Problems in Biology (IMPB) as institutes of Russian Academy of Science …

Acknowledgments

I am grateful to several people (especially to Georg Trogeman, Alexander N. Nitussov and Wolfgang Ernst) who organized the publication of the book mentioned in [3,4] that contains much information concerning computing and networking in Soviet Union. Thanks also go to the Ministry for Schools, Education, Science and Research of the German state North-Rhine Westfalia and to the Academy of Media Arts Cologne for supporting this publication.


V I Smirnov
email: svi@ipmce.ru

Some Hardware Aspects of the BESM-6 Design

Keywords: General-purpose computer architecture, instruction pipe, logic circuit design, mechanical package

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

The Institute of Precise Mechanics and Computer Engineering (IPMCE) developed the general-purpose computer BESM-6 under the leadership of academician S.A. Lebedev. It became operational in 1967. The BESM-6 integrated the latest architecture features and domestic experiences with many original solutions that provided high efficiency and exclusively a long period of exploitation.

First computers were installed in major scientific and cosmic institutions and had played important role in research and development domestic science, defense and technology. Later BESM-6 had undergone several modifications and successfully operated in different fields of industry and education as one of the most popular general-purpose computer. Up to four hundred computers were produced with modifications of input/output and memory parts and some computers are known in working state nowadays.

This paper is devoted to some hardware aspects of the BESM-6 central processing unit piping not reflected in other paper about software. Of particular importance in achieving high performance was flexible instruction pipeline for the CPU with large throughput and deep look ahead. Its integration with all previously mentioned characteristics permitted to create large amount of mathematical software and application packages. During the BESM-6 lifecycle, rich software was designed including compilers for all known programming languages, operating systems, and application packages as the largest domestic soft fund.

BESM-6 Characteristics

Basic Architecture

BESM-6 pipeline was designed independently of well-known Stretch computer; its chief designer S.A. Lebedev called it a "water pipeline". It was investigated in detail on a program model. The pipeline architecture of the BESM-6 CPU actually had all features of contemporary microprocessors but with very limited resources.

Original logic elements with paraphase synchronization allowed creating flexible command pipeline for the CPU with 300 ns instruction cycle time and deep look ahead (six and more instructions). Unique torodial ALU with very fast cycle time. The general block-diagram of BESM-6 central processing unit appears in Fig. 2.

БРЧ

-buffer for operands from memory (300 ns).

АЗ-БРЗ

-associative buffer for results written to the main memory (300 ns). The oldest unused result was transferred to memory.

АУ

-toroidal multifunctional ALU with many interesting solutions for special paper.

The control unit coordinates control the operation of all functional units and it includes an interrupt system, I/O operation, and many other functional units to support effective work of operating system.

The base for the system of semiconductor logical elements was a differential amplifier with common emitter and wide pyramid of diode logic (Fig. 3). It included back link gates for the latch function and had an AND-OR-AND-pyramid to set the latch in definite state. One may say that this logical element base supported original construction solutions that allow the design of a very effective and reliable computer.

Fig. 3. Basic logical unit

Four amplifiers with backward gates were placed in one physical block (Fig. 4) with their state indicators. Input logic was in other physical block (Fig. 5), which was placed on the opposite side of chassis as close as possible to keep wires short (Fig. 6). It is the use of all these constructive solutions with an original paraphase synchronization based on two sinusoidal signals with 10 MHz frequency that permitted a clock of 100 ns in pipeline processing.

The integral use of all mentioned solutions allowed them to reach a rate of 1 MIPS using ordinary domestic semiconductor technology, which had the best components per operation ratio.

Four chasses with У-blocks were placed in one cabinet and four adjoining cabinets, showed in Fig. 1, display all CPU latches and permit direct physical access to all contact points for oscillograph.

The test and diagnostic system provided extremely high results in maintenance and finding accidental faults. All this made possible extremely long periods of reliable operation in many computing centers.

Figure 1

 1 Figure1shows the front view of the BESM-6 CPU in its working state in 2006. Some of its general characteristics include the following:o 48-bit word with 2 parity bits in memory (one for each half-word)

Fig. 2 .

 2 Fig.2. General block-diagram of BESM-6 central processing unit.

Fig. 4 .

 4 Fig. 4. Fragment of chassis with У blocks

Fig. 6 .

 6 Fig. 6. У-block.


G B Efimov
email: efimov@keldysh.ru

I B Tshenkov

E Yu Zueva
email: ezueva@keldysh.ru

On the History of Computer Algebra at the Keldysh Institute of Applied Mathematics

Keywords: Computer algebra, mechanics, mathematics, programming, history, KIAM, REFAL

The authors consider the history of Computer Algebra (CA) development and applications at the famous Keldysh Institute of Applied Mathematics (Russia Academy of Science). At the Institute CA was used in various areas: Applied Celestial Mechanics, Mathematics, Robotics, Hydromechanics, and Methods of Calculation. Authors compared and classified the existing systems and their possibilities

Introduction

The Keldysh Institute of Applied Mathematics of the Russian Academy of Science (KIAM RAS) was the first and one of greatest centers of computer science in the Soviet Union. M.V. Keldysh founded it in 1953 for solving difficult scientific problems of national importance. From the very beginning, it was the problem of modern physics, from mathematical and computational point of view. Later the Institute obtained the significant results in such scientific areas as space mechanics, physics, mechanics, cybernetics, programming and others. At the Institute, the experts in different areas such as mathematicians, physicists, mechanical engineers and computer scientists worked together, and their contacts with each other became the source of fruitful ideas. Such famous scientists as A.N. Tichonov, K.I. Babenko, I.M. Gelfand, T.M. Eneev, A.A. Liapunov, D.E. Okhotsimsky, A.A. Samarsky, Ya.B. Zeldovich, V.S. Yablonsky, K.A. Semendyaev, O.B. Lupanov, M.R. Shura-Bura, A.N. Miamlin, S.P. Kurdiumov, N.N. Chentsov were among them. Numerous difficult problems required various mathematical methods for their solution. These scientists were using the early computers and they were experiencing the early successes in this new field. These successes, in turn, gave all of them the enthusiasm to generate many interesting ideas.

Soviet programming, different directions of computer science, and modern methods of computations were born in this first period. It is interesting to mention that our Institute was among the first users of new computers. We received Soviet-made computers ‗M-20' with serial number 1 and ‗BESM-6' with serial number 2. We also had the opportunity to use some others Soviet computers such as ‗STRELA', ‗BESM-3' and ‗BESM-4', and various computers from the ‗ES' series. When programming as a new kind of activity had appeared, it required new people. A number of professional programmers worked in the Institute; they created new languages, translators, systems, and packages. Note at that time, that applied scientists, physicists, and mechanical engineers stimulated this process and participated in it together with professional programmers. They also were the authors of software in the 1960s, 1970s, and later.

Applications in Computer Algebra

The idea of symbolic computations arose just after the appearance of computers. It started as a will to make computers able to interact with humans via an ordinary mathematical language and to facilitate the job of physicist or mechanical engineer. Thus, the history of computer algebra (CA) in the Soviet Union and Russia spans a half century. This history is presented in several reviews and conferences papers [START_REF]Calculus mathematics and computer facilities[END_REF][START_REF] Ershov | Development of programming in USSR. Part 1. Initial development. Part 2. Step to second generation of languages and computers[END_REF][START_REF]Computer analytical calculations and their application in theoretical Physics[END_REF][START_REF] Gerdt | Analytical Calculations on ECM applied to Physics and Mathematics[END_REF][START_REF] Miola | -A bibliography of soviet works in algebraic manipulations[END_REF][START_REF] Grosheva | Computer analytical calculation systems (Applied Analytical Packages)[END_REF][START_REF]Systems for Analytical Manipulation in Mechanics. All-Union Conference[END_REF][START_REF]Applied Program Packages. Analytical manipulations[END_REF][START_REF] Grosheva | Computer analytical calculation systems[END_REF][START_REF] Brumberg | Specialized Celestial Mechanics systems for Symbolic Manipulations[END_REF][START_REF] Klimov | Computer Algebra Methods in Mechanical problems[END_REF][START_REF]Computer Algebra in Physical Research[END_REF][START_REF] Abramov | Computer Algebra. -Programirovanie[END_REF][START_REF]The History of Computer Algebra Applications[END_REF][START_REF] Grosheva | Symbolic Manipulations in Control Theory[END_REF][START_REF] Efimov | Computer Algebra at Keldysh Institute of Applied Mathematics[END_REF][START_REF] Grosheva | A History of Computer Symbolic Manipulation and its Applications in Mechanics[END_REF]. This list includes some works of authors of this paper devoted to the application of CA and CA systems in mechanics, dynamics of multi-bodies systems, theory of control [START_REF] Grosheva | Computer analytical calculation systems[END_REF][START_REF] Grosheva | Symbolic Manipulations in Control Theory[END_REF][START_REF] Grosheva | A History of Computer Symbolic Manipulation and its Applications in Mechanics[END_REF] and to CA investigations at Keldysh Institute [START_REF] Efimov | Computer Algebra at Keldysh Institute of Applied Mathematics[END_REF]. The review [START_REF] Grosheva | A History of Computer Symbolic Manipulation and its Applications in Mechanics[END_REF] contains detailed references to more then 500 original works.

It is interesting to remember the very first attempts to use symbolic, non-digital way of interaction with computer, at the age when most of scientists considered computer as a big and not very convenient calculator only. In their historical review, A.P. Ershov and M.R. Shura-Bura [START_REF] Ershov | Development of programming in USSR. Part 1. Initial development. Part 2. Step to second generation of languages and computers[END_REF] mentioned only the first works of Leningrad's school. We will add the works of some other groups of authors made in Russia as early as the beginning of the 1960s.

In 1956 at the first National Conference devoted to computer science, A.A. Dorodnitcin formulated the task that we can consider as the beginning of symbol manipulation in the Soviet Union [START_REF] Dorodnitcin | Solution of mathematical and logical tasks on computer[END_REF]. He proposed to build solutions in the form of two asymptotic power series, conjugated by a common numerical solution in the regular area. Thus, analytical approach was combined with numerical one. D.E Okhotsimsky from the Keldysh Institute applied this approach to a space dynamics problem [START_REF] Okhotsimsky | Research of motion in central field of forces under the influence of constant tangent acceleration[END_REF]. He also built two asymptotic series conjugated by a common numerical part. Automatic building of asymptotic construction on one of the first Soviet computers, the STRELA, was innovation per se.

A.A. Stogny [START_REF] Kantorovich | On a mathematical symbolic system convenient for computer's calculations[END_REF], the follower of V.M. Glushkov in Kiev, resolved the task formulated by Dorodnitcin. He proposed an algorithm to obtain the polynomial solution for a differential equation. It was probably the first result of the famous Kiev Computer Algebra School. At the same time, Nobel laureate L.V. Kantorovich investigated some types of symbolic notation for computer algebra in the Leningrad's branch of the Steklov Mathematical Institute. His follower, T.N. Petrova, created the program -Polynomial Prorab‖, used later for the tasks of theory of elasticity and other applications [START_REF] Stogny | Solution on DCM of one task concerning differentiation of functions. -In: Problems of Cybernetic[END_REF]. N.N. Yanenko, who started his scientific way at KIAM, investigated Cartan's methods of the analysis of compatibility of systems of differential equations in partial derivations and realized it on the STRELA computer [START_REF] Shurygin | On a realization of algebraic differential algorithms on ECM[END_REF]. In Leningrad, at the Institute of Theoretical Astronomy (ITA RAS), V.A. Brumberg and his colleagues developed solutions of some problems in celestial mechanics in series form [START_REF] Brumberg | Polynomial Series in Three Bodies Problem[END_REF]. Later, they elaborated and expanded this approach. The group of L.V. Kantorovich in Leningrad and V.K. Kabulov in Tashkent elaborated a similar approach to the tasks of the theory of elasticity [START_REF] Kabulov | On deduce of differential equations of elasticity and construction mechanics[END_REF].

The Keldysh Institute was among the first developers of symbol manipulation and began the first attempts to use them in the area of applied celestial mechanics. Z.P. Vlasova Since 1963, M.L. Lidov with his group implemented numerous experiments concerned CA application to satellite dynamics problems. It was impossible to use existing general-purpose CA systems because they were very primitive at that time to solve such complicated problems. He proposed a method to unite both analytical and numerical approaches. For elliptic orbits and perturbations of different sorts, he used the analytical approach to construct the Hamilton perturbing function. Then, he calculated the right-hand parts of the perturbed motion equations in numerical form in every step of the integration. He implemented this calculation, using a Hamilton function derivation. This approach provided a high accuracy method for motion calculation and it allowed the avoidance of labor-consuming analytical calculations. As a result, very sophisticated special algorithms and programs were elaborated and used by M.A. Vashkoviak, A.A. Soloviev, Yu.F. Gordeeva, and other followers of M.L. Lidov. Unfortunately, these investigations did not stimulate the development of CA systems for common usage.

Let us mention some works in the area of fluid and gas dynamics. I.B. Tshenkov and Ya.M. Kajdan resolved several hydrodynamics problems with the aid of a REFALbased CA program. M.Yu. Shashkov and L.N. Platonova applied similar methods using REDUCE. In the area of dynamics of complicated multi-body systems (e.g. robotics, spacecraft), they used CA for deriving the equations of motion, stability investigation, automatic generation of program of numerical analysis, and other applications. They created the PAS and others systems used for deriving equations of motion and for solving some problems of the theory of control. Computer algebra applications to mechanical education were developed by D.Yu. Pogorelov, the follower of V.V. Beletsky.

REFAL and its Use

The very interesting page in Russian cybernetics is the history of REFAL. In 1969, V.F. Tourchin created REFAL -an original computer language based on a new principle of programming. He used associative text processing based on recursive function theory without directly addressing control of the program [START_REF] Turchin | Metaalgortmic Language. -Cybernetika[END_REF]. From the beginning, computer algebra was among potential areas of REFAL applications. However, the first realization of REFAL was more -scientific‖ then practical because it was isolated and not compatible with -ordinary‖ software such as numerical packages, library support, and memory allocation. Additional efforts of many people required to make REFAL modifications usable in a practical way, in particular for computer algebra applications. S.A. Romanenko and A.V. Klimov from the group of V.S. Shtarkman created high-effective compiler from REFAL [START_REF] Turchin | Refal-5, Programming Guide and Reference Manual[END_REF].

V.F. Tourchin and others developed the first REFAL program to solve some problems of nuclear physics in series. This program demonstrated some CA features. I.B. Tshenkov elaborated a general-purpose CA system named SANTRA and later modified it. Later I.B. Tshenkov and M.Yu. Shashkov made the special applied system, called DISPLAN, for processing non-standard difference schemes. M.L. Lidov and L.M. Bakuma were among the first REFAL users in the applied areas. They attempted to process Poisson series. H.C. Ibragimov and I.B. Tshenkov made attempts to apply REFAL in the group theory. Initially, the plan was to use REFAL as a -meta language‖. However, people began using it in a wide scope of tasks similar to CA, where text processing was necessary. V.A. Fisun, A.I. Khoroshilov, and others developed computer languages based on REFAL, such as SIMULA-1 and DYNAMO. A.N. Andrianov and K.H. Efimkin automated the calculation of difference schemes in the NORMA system.

The KIAM united some of the enthusiasts of REFAL and they worked closely with it. V.L. Topunov with his colleagues from Moscow State Pedagogical Institute used REFAL-based CA system in differential geometry. Together with V.P. Shapeev and the other followers of N.N.Yanenko in Novosibirsk, they used the method of H. Cartane and investigated the characteristics of difference schemes. L.V. Provorov at the CAHI (Professor N.E.Zhukovsky Central Aero-Hydrodynamic Institute) and at the Bauman High Technology University, O.M. Gorodeskiy (Grodno) and A.V. Korlyukov created a CA system for numerous application areas in engineering. They could derive the equations of the motion of multi-body systems automatically. Use of REFAL allowed presenting the equations in convenient form near to human presentation. L.F. Belous and I.R. Akselrod (in Kharkov) used REFAL for the integration of several different programming systems and numerical packages into a united system; included in this system is the well known REDUCE package and the domestic computer algebra package called SIRIUS.

At the Keldysh Institute, some leading scientists investigated the possibilities of increasing computational efficiency. They did it by creating specialized blocks/computers, united in the complex system. This was the way to process effectively various tasks, numerical as well as symbolic; indeed, REFAL was appropriate for them [START_REF] Zadyhaylo | Some problems of Computer design from blocks of high qualification[END_REF]. A.N. Miamlin, I.B. Zadyhaylo, and V.K.Smirnov were the leaders of the project [START_REF] Myamlin | A Specialized Symbol Processor. -Fifth Generation Architecture[END_REF]. L.K. Eisymont analyzed REFAL efficiency for both software and hardware realization, and in particular from the CA application point of view. V.K. Smirnov with his group simulated the REFAL processor EC-2702 on the EC-2635 computer using microprogramming [START_REF] Smirnov | Hardware REFAL realization at KIAM[END_REF]. This processor was compatible with EC-series of computers and they used it for CA problems as well as for translators. K.I. Babenko, A.V. Zabrodin, and I.B. Zadyhaylo investigated the possibility of designing a highly efficient parallel computer for applied (aerodynamics) problems. Recently A.V. Zabrodin and others developers used this early result to create the Russian MVS-100 and MVS-1000 supercomputers; the MVS-1000 had an efficiency of about 10 power 12 operation per second [START_REF] Zabrodin | Super-Computers MVS-100, MVS-1000 and its applications to problems of physics and mechanics problems[END_REF]. The programmers successfully used REFAL-oriented software design techniques for creating supercomputer program environments.

A New Era

At the beginning of the 1980s, CA popularization and systems comparison became important, in particular for mechanical tasks that required computer experiment for their investigation and solution [START_REF]Applied Program Packages. Analytical manipulations[END_REF][START_REF] Grosheva | Computer analytical calculation systems[END_REF][START_REF] Grosheva | A History of Computer Symbolic Manipulation and its Applications in Mechanics[END_REF]. In 1982, scientists successively used CA for constructing difference schemes in the area of non-regularity. A.A. Samarsky, a leader in Soviet mathematical modeling, evaluated favorably the result of this work. With the aid of A.A. Samarsky, KIAM became one of the main organizers of the First National Conference on Computer Algebra Applications in Mechanics held in Gorky (now Nizhny Novgorod) in 1984 [START_REF]Systems for Analytical Manipulation in Mechanics. All-Union Conference[END_REF]. The participants of the Conference discussed the results of about twenty years of research, as well as plans and perspective directions of the subject. Later, a number of conferences and seminars on CA had taken place in Russia.

G.B. Efimov and M.V. Grosheva began to classify and to generalize the experience of the common work of mathematicians, mechanical engineers, and programmers. There were many reviews of CA systems and CA applications for mechanical problems [6, 9, 14 and 17]. The reviews provided users with tables of CA system features. They also provided a convenient tool for CA system comparison and selection for potential usersexperts in applied areas. Such analysis was useful for CA developers as well. First, CA systems were usually specialized and elaborated for concrete task solution. For example, in the area of dynamics of multi-body systems they created many various CA systems, so the classification and comparison of their features became important. Later, well-known modern universal systems such as REDUCE and others appeared and people used them for the realization of algorithms. Currently, computing specialists use CA as a necessary standard tool in large complex programs, often without any special mention. Information about CA systems in mechanics was accumulated during the classification; this work has now become a valuable tool for applications and an important contribution to the history of computing [START_REF] Grosheva | A History of Computer Symbolic Manipulation and its Applications in Mechanics[END_REF].

Finally, we would mention some results obtained recently. A.D. Bruno and his group obtained new important results [31]. It concerned some algorithms of normalization in Hamilton systems and investigation of Newton polyhedrons. S.Yu. Sadov and V.P. Varin investigated the stability of motion for several problems of celestial mechanics [START_REF] Bruno | The limit problems for equation of oscillations of a satellite[END_REF]. A.S. Kuleshov [START_REF] Kuleshov | On the first integrals of Equation of motion of a Heavy Rotational Symmetric Body on a Perfectly Rough Plane[END_REF] generalized the classical work by Chaplygin. Using CA he found some new cases of integrity and the first integrals in explicit form. A.W. Niukkanen and I.B. Tshenkov developed a system of transformations for hypergeometrical series [START_REF] Niukkanen | Operator factorization technique of formula derivation in the theory of simple and multiple hyper-geometric functions of one and several variables[END_REF]. Some authors used CA to generate the equations of motion of multi-bodies systems, and to simulate the dynamics of these systems. In the situation when it was impossible to use CA directly, some people developed other similar methods. For example, D.Yu. Pogorelov [START_REF] Pogorelov | Some developments in computational techniques in modeling advanced mechanical systems[END_REF], I.R. Belousov and I.Yu. Balaban [START_REF] Belousov | Calculation of the Robot Manipulator Dynamic Equation[END_REF] developed such methods to simulate multi-bodies systems with a great number of degrees of freedom, such as robots and transport systems.

  and I.B. Zadyhaylo implemented the first manipulations with trigonometric and power series on Soviet STRELA computer. In 1964, D.E. Okhotsimsky initiated work on a semi-analytical solution of a space dynamics problem for the low-thrust flight in a central field of gravitation. G.B. Efimov realized this approach for a simple Poisson series in 1970. Since 1970, A.P. Markeev used CA for normalization of Hamilton Systems and periodic solution stability analysis. His follower, A.G. Sokolsky, made the next steps in this direction. This work continued by the same group at Moscow Aviation Institute (MAI) and later by A.G. Sokolsky in ITA RAS in Leningrad. At MAI, they developed computer algebra applications to education as well. V.A. Saryshev and S.A. Gutnik used CA for the problem of satellite equilibrium stability in 1984.