Scientific and Technical Intelligence Report
Computer Research and Development in the People's Republic of China
350
5
Research and Development People's Republic of China
The
targe-icalc computer models exceeding the performance of US models commerclully availableurther. It it believed that the Chinese, using Integrated circuit technology, have already built their first versions of airborne digital computers for navigation and control.
In the next few yean they probably will progress rapidly inore powerful large-scale computer at well as nn extensive variety of small andmprovements In the performance and quality of peripheral equipment, however, mint be made ond. more important, software development and user service must be Riven greater attention If the Chinese hope toarger number of computers effectively or to use them In more sophisticated applications than they now do. In addition to developing more advarvced domestic computers and related equipment. Ihe Chinese probably will attempt tn purchase from Western and Japaneseew of the largest computer* commercially nvullable.
COMPUTER RESEARCH AND DEVELOPMENT IN THE PEOPLE'S REPUBLIC OF CHINA
";
;
5
CENTRAL INTELLIGENCE AGENCY DIRECTORATE! OF SCIENCE AND TECHNOLOGY OFFICE OF SCIENTIFIC INTEUIGENCE
PREFACE
Thin report cvuluatcs Chinese capabilities und trends In the design und construction of digital computers, auxiliary storage devices, and peripheral equipment, as well as In the development of software for such computers, in particular. It evuluutcs Chinese capabilities to design and build large-scale computers und highly miniaturized computers, two categories of computers thut are of the greatest significance for both civiliun und military application. The report docs not uttempt to evnlunte Chinese progress In analog computer developments. Very little information on such developments has become uvuiluble since the Cultural Revolution und recent information indicates that the Chinese arc primarily concerned with digital technology. This report was prepared hy the Office of Scientific Intelligence and coordinated within CIA. The cutoff date for Information Is
Si
- irrnrr
fi I
CONTENTS
PREFACE
. ill
CONCLUSIONS
2
DISCUSSION
Status and directions of
Organization of computer research and
Military development and applications nf
Large-scale
Small and
Auxiliary storage and peripheral
Computer
Supporting component
APPENDICES
Page
of PRC Digital Computer
of Selected PRC Digital
Page
Comparison of PRC and US Large-scale Computer Models
Page
omputer at Peking
DJS-ll Circuit
omputer at Shanghai Radio Plant No.
Unidentified Chinese
computer research and development in the people's republic of china
PROBLEM
To assess ihe status and trends In the development of Chineseand related equipment Including those having possible
CONCLUSIONS
For priority civilian nnd military programs retiuEr-ing the use of large-sculc digitnl computers, the, People's Republic of Chlnu (PRC) hus buill ut leust two computer models3 that ore as powerful us the largest US machines commercially available beginningt is estimated that within theears the Chinese wilt be ublc to assembletindomputer with nearly twice this capability. During this period the number and performance features of domestically developed large* scale computers probably will not be adequate to satisfy all priority needs, which according! to the Chinese would include applications in numerical weather prediction, control of large! Industrial complexes, and seismic datapresumably, in military developments. The Chinese have rt-entlyarge-scaleomputer from France and probably will attempt toew larger machines from Western and Japanese sources.
hing smull-scule Integrated circuits, the Chinese mny have built n* curly0 small, airborne digital computer* for navigation und control. Nn detulted specifications are available fnr such compiiler* but they probably are very limited functionally, with practically no programming flexibility. The level of circuit and component technology used in such computers may be comparable In cnmplcsity with thut of US aircraft computers of the early lOfiOs. but the Chinese could significantly Improve their airborne compulenesult of the rapid progress ihey ui making in integrated circuit technology.
espite their notable achievements in hardware development, tbe Chinese hove set lo recognize the relative importance of computer softwareequipment standards, maintenance, und other user support activities. These ureas will probably be majorifficulty for the Chinese as they attempt to male effective usearger number of computers or more sophisticated use of them. Further, the geographic dispersal of Chinese computer development und production has created wide variations in tlto quality and reliability of computing equipment. Another constraint Is the limited performance and reliability of Input/output nnd auxiliary storage equipment. Efforts toquipment have Ixrn started only recently.
reutrr variety of digital computersntegrated circuits pmhuhly will he announced by the Chinese during Iheevelopment efforts will probably emphasize minicomputer* and large-scale computers with expanded cupulalities. Minicomputers for such application* a* industrial control, testing, ami small-scale engineering problem solving undoubtedly represent the class of computers, most needed by the Chinese. Improved machine performance in all cluws nf computers prolnblv will be achieved svilh both sophisticated system
architecture and more advanced Integrated circuit technology. But Improved performance In large-scale modeb muy I* handicapped by Chinese Inability lo fabricate core memories withhigh speed*.
omputer developments In the PRC are expected to remain geographically dispersed, although for (elected priorityumber of the major organizations may be forced to combine resources. Military computer developments probably will be accomplished primarily by organization* separate from, hut receiving support from, mujor academic und Industrial computer development facilities. Chinese application* nf computers. particularly large-scale models, have emphasized and probably will continue to emphasize stand-olone Installations for scientific nnd engineering problem solving. The Chinese show little capability to Implement more sophisticatedor Interactive computercs those associated with automated command andlications.
SUMMARY
he PRC hus displayedn new cornputer models, al] Incorporating Integrated circuit components. The larger of these new models, which are also the most powerful digital computers yet displayed by the Chinese, are the DJS-ll built at Peking University and theuilt by the Shanghai Radio Factoryhe performance of both modeb lies between that of the US0 rnodel. first availablend that of the0 model, first availablehe PRC models, however, exist only In prototype or In very few units. Thehe first Chinese digital computer known to have sophisticated system and logical design features. These features allow parallel memory accessing, parallel Input-output operations, and Instruction look-ahead, all of which make possible higher operating speeds without major Improvement In Internal memory speedv Such design concepts were first used in US rnachlnei during the. The Chinese have also mode use of rnodular design concepts (as seen Inodel) that permit wide lle*lhlliry In the construction nf large special purpose computer systems, j
Chinese application nf Integrated circuitcomputers appears In be progressing muchthan has occurred previously inMore advanced integrated circuit,used In current computer modeb haveIn Chinese component hondbonk*By comhlning thethe DJS-ll
odel* wilh the more advanced Integrated circuitr even with high-speed transistors if ihey become available In Huffldent quantities, ihe Chinese should be able toomputer with a* much us twice ihe perfnrrnonce capability of theemory technology muyemporary though *lgnlficont constraint In *uch developments The Chinese are still dependent on fertile core technology for Internal memories and have notapabilily to assemble memories with cores huving diameters imull enough to achieve cycle time* of less than one microsecond.
Strong Chinese interest In developing or acquiring computer* more powerful than the DJS-ll andas been apparent sincepublications as well as In contacts wilh Western computer specialists3 the Chinese attempted to acquire such computer* from US and other foreign manufacturers but were unsuccessful. Recently Ihey purchased an IRISodel From the French but continuing needs for larger computer models should prompt additional purchasing efforts.
Considerable evidence has been found to suggest that In the nest few years the Chinese mayreater variety of minicomputers and other small computing and calculating equipment for industrial and scientific applications,
Inese versions with capabilities comparable eody US minicomputer model* have appeared In Isolated Inilance*trong Chinese interest In the engineering construction of minicomputers ha* been evident In discussion* with US and Japanesehis Interest may have been prompted In part by military airborne computing developments, though minicomputers can certolnly satisfy Ihe majority of Chinese civilian computer requirements for such use* a* industrial control, testing, and small-scale engineering problem solving.
The Chinese SAT University In Peking and the Fourth Institute of Ihe National Defense Scientific
Committee in Peking pmliulily were responsible0 for using Integrated circuits to build on airborne digital computer for navigation and control. Integrated circuits described In handbooks appeared In prototype computershese Integrated circuits in well as multilayer printed circuit bourds fabricated by the Chinese are com punt bin with those used in US airborne computers buill
The Chinese have reached the stage In which the limited performance and poor relluUhty of auxiliary storage and Input/output equipment are recognized as major handicaps to the full utilization of computers. The best exomplcs of Chinese magnetic drum and tape units, which are used withew; known models of Chinese computers, are comparable with US commercial models uvuilable In the. The only exampleagnetic disc unit, which is used in the only knownnstallation, compares favorably with the Tint US units availableaper tape, typewriters, and other Input/output equipment have changed very little In theean or more,ew very modem line printers and digital plotters comparable with US models available In theave begun to appear.
The Chinese computer delegation that vislled the United Stales3 deariy expressed Chinese concern for developing improved peripheral equipment for computers, and they probably acquired useful Information on equipment design and assembly.t least In the reliability of this equipment, are necessary before the Chinese can attempt to Implement more sophisticated real-time or interactive computer systems.
Software developments lag considerably hardware developments In the PRC Higher-level programming language compiler* have been written for many computerhe most thoroughly developed one being the ALGOL type fur the KMC In contrast operating systems In general are very primitive. Recent visitors to the PRC have observed thut knowledgeable Chinese software specialists are not generally aware of the significance of such basic concept* as Job control language* and certain memory protection techniques. It Is also dear lhat the Chinese do not appreciate the importance of maintenance and other support for computer users. Nor have they taken measure* to establish equipmenthis Is not surprising: since the Chineseery small Inventory of computer Imtullullons. most of which ure used in sdentlfic und engineering problem solving. The lack of attention to these area* even at thl* caHy stage, however, suggests that the Chinese will make very slow progress in the more sophisticated applications of computer* and in the effective use of greater numbers of computer* when they become available.
Computer development in the PRC Is much more /idespreud than hus liecn report
e major uevelopment cent ii cities and in Shenyang, but many development efforts, especially military, uppear to be conducted ul oilieruch us Ilurbin. Siun, Chungking, and Wuhun In the PRC there Is no identifiable centralized direction for computer development or established standards for computer equipment, except possibly for military developments. Few detaib are avuilaltlc regarding specific military computet development* but the technology involved does not appear to be markedly different from or more advanced thun that observed openly at well-known organizallons. In some case* the assembly of the same computer models by different organization* using local materials und tulent has resulted in serious1 reliabilityossibly occurring even in priority programs
DISCUSSION
AND DIRECTIONS OF DEVELOPMENT i
Since the withdrawal of Soviet technical assistance from the People's Republic of China (PRC)hinese computer technology has gradually evolved from one that was essentially Soviet-based, to one which reflects strong Japanese and Western influence.
0 tn5 new computer model announced by the Chinese were primarily extrapola lions and modifiedof the earlier Soviet5 toariety of transistorized models were developed thattronger Western than Soviet influence. The Cultural Revolution in theurtailed many computer development activities but did not seriously affect
ul ccrtuln1 the variety of new Chinese model* hu* Increased markedly und virtually ull nxHiel* now Incorporate liitegrutctl circuitost of very limited complexity (see appendix Ai.
Chinese import* of Japanese and Western Kuropcun computen0 reflected the inability nf the PRC to latiify Its own military and civilian requirement* for computers In ull size* ond performancelthough quantities of Imports were never great,0 they dwindled considerably, suggesting that the Chinese probably have been able to satisfy their own need* ator -in.Jl und medium size computer*.
The Chinese shift lo integrated circuit technolngy may hove been promptedumber of cnn*ideration* but two reason* ore Immediately apparent: the propaganda volue of developing andomponent technology which can lie closely compared wilh leading worldwidetechnology, and the savings in lime and cost for constructing assemblies with integrated rirrxiit components versus discrete translslrvs. The latter reasonajor considerationimilar transition that occurred earlier in the WeM. Cleudy, the Chinese established integrated drcuit technology much quicker than thecnusc thry wcrr able to lenrn from Western experience und acquire the manufacturing skill that the West had earlier Invested time and effort In develop.
Organization of Computer Research andi i
Computer research ami development In the PRCurc conductedurge number of research Institutes, universities, plant facilities, and militaryA partial listing nf these organizations and their relationship* with specific computer developments are shown In uppendix A. Peking. Shanghai, and Shenyung hove been known to be the location* of the major development and productionecent information Indicate* that several other! cities Including Harbin. Slan. nnd Chungking are Important loca lions of special purposeome of which directly support the military. The Chinese Academy of Sciences, the Fourth Ministry of Machine Building, and the Sevrnth Ministry of Machine Building direct most of the rr-venrch nnd development uctlville* that have been identifiede major
Insllltitei and plants. There is, however, no evidence of central direction forcornpulerdevHopmcnt nor of any effort* to csluhllsh national standard* for enmputer-rrlaled equipment.
There I* little evidence ofamong development organization* except among those within the Chinese Acudimy of Sciences or the Fourth und Seventh Ministries. In fuel, there have been numerous example* of parallel developments of cumputrrs with comparableh usilhnd theith theach locality tends to binld machines for local requirements using locally uvulluhle mutcrials undecent information Indicate* thai some computer model* such usave been huilt and possibly modified by different organization* using documentation provided by the responsiblehe extent of Ihi* Iransler of computer design documentation is unknown butractice that is likely to be followed by some organizations that support the military.
While computer model* are designed and built at universities and research institutes and at times transferred to ihe plants for production, the plants ubo design their ownhese are generally of higher quality und reliability. Computers designed ami built at the academic facilities undergo frequent modification* und in some coses serve as test Iteds for software development and a* specialem cmfihurutiom for users. Serious reliability problem* have been attributed to recent modeb. such as ihe III. Itecuirse of poor quality ussembly
Available evidence Indicates that cumprehenmc maintenance und other user support activity are not provided by computrr manufacturers. There are abo no indications thai the Chinese are planning to establish In the foreseeable future support nrguniza-tions for thesenow appreciate the importance of such support. Current priorities seem to hr conccrnrd with manufacturing capabilities.
Military Development and Application* of
Information regarding military computrror military computer application* In the PRC is extremely limited.
The largest und highest performance Chinese digital computers displayed2 htive aimom Ihe first integrated circuit models. The first of tl larger Integrated circuit computer models,uilt by the Institute of Computer Technology. Peking, ami. built hy tlie Institute Computer Technology. Shanghai, appeared to experimental developments in which theore concernedthe assembly and rlrctfoal features of Integrated circuit machines limn wit elaborate system design.
s noteworthy because of its modular construction, allowing upward expansion in both log'c and memoryhis fniture is particulaHy! Important in the construction of special purpose systems for unique application* Including those for military uses.
Figure I,ompwicr o" Peking Univeriily
DJS-II computer, tinnnunccd in Augustepresents llir lurgest und most |mwerftil digllul computer displayedie Chinese und the first Chinese application of sophisticated system designs for increased rf<irniuiicc (w fifjun* njor characteristics of tlte DJS-11 un-i appendix B. hot tbe most notable of these :irr Ihe arithmetic speed and Internal memory capacity, which greatly escred those of previously displavcd models. An arithmetic speed nf one million operations perrn published by the Chinese, hut separate rrporlsycle limeicnwomls indicate that the actual machine speed, closer lo StK) ihoifsiiiid operations |ierhe design ami construclion nl theequired *uppnri Imm severalnns in Peking and elsewhere and rs the first known Instance In whichoint effort has been nmdr. Il illustrates the limitations of ihe dispersed nrgniti/alinnul slnictnre of computer HAD in China.
In terms of pcrfntTrtarRT. tbehich cxisls In prototype nr scry limited utunl>ers. lies lietwectt the
irsl dclisercd ill theSlalom IBM
andirstn llHv>(srr lablel The irtctiMUsI pcrf.-rmantr ol tlie*nll of ssvleiu design featun's. such as memory overlaps, instruction look-ahead, and parallel in put/outt These characteristics perinilir.illrl machine operations involving an inherentlv slow internaluch design timcrpK applied Inmachines built in Ihe early IQuOs. are allractlse when internal rnemorh* are consiricnlilv dosserrllbmelic and logic circuits anil tintslllenti i. in aiiiiesiuc increased computerWhile leclitiic.il details bit lacking regarding certain other recent computer hmhIcIs announced by Iheheppearsie first mntM incorporating all itf these'reVHnpJs built models, such u* the III. displaysimple, straightforward machine urchilecliini in which memory cycle lime ism- litniling iH-rfiirniuiwe factor "
lutegraled circuits used in theo be comparable in sophiston althninth comiderahli
-
Table
Comparison of PRC and US Large-scale Computer Models
TQ-9 0 0 0
year of availability Add time (mieroswondi) Storage cycle time (mieroeecoodi) Maximum -torag* capacityWord length
iU
B MU
O bit*
notated value*.
' ChltiMo model*nly In prototype.
in performance than those used in the earlier integrated circuit computers^
|Published articles Indicate that theses thick film and semiconductor circuits,3 Chinese computer delegation to the US reported the use of Schottlcy high speed TTL (transistor-transistor logic) circuits in theT Recent photographs of the circuit boards of thesee figurendicate that some of the circuits are externally similar to and may correspond with the 5JZ bipolar types shown in0 components handbook published in Shanghai. The 5JZ circuits contain no more than one or two logic gates per package, which is essentially the same as circuits described In earlier computer
compnr
Another Chinese integrated circuit computer modeleported speed of one million operations per second, theas recently been obse'ved In prototype at Shanghai Radio Plant No.seeturger Internal memory than Iheut the details on performance und system design that wouldore accurate comparison with the DJS-il ure not uvulluble.
A substantial Chinese interest in the engineering' design and assembly of digital computers much larger than thendas been evidenthinese translations of US publications reflect in-depth research of the literature on the designs of some of the largest US machines, such as theroduced during themmmmmm
Chinese needs for large-scale computers with gr performance levels than domestically orlginut models became particularly apparent3 whrr the Chinese Iwgan negotiating with IBM for tl purchase of its largest commercially uvailable rn<H.MSpecific end uses fnr the impr.rtr computer were not Identified,ikely use would have beenajor computing center such us tliti Institute of Computing Techniques In Peking. Because of Chinese refusal to submit end-use dncoilicnlntinnj required bv export emit rub. the IBM negotiations were termiilulcd.iuese also have been oecjiliuliiit*ll* the Japanese fur a. larce system, hnl ihe stain* nf lliesenut known al the presentit1 the Chinese purchasedt IN (if) model from the Fn'iu'b fnr processing seismichis is the only Chinese acquisitionarge-scale computer since the Cultural Revolution; but Itcvaiise the IHLSfill I* comparable with anl probably
suttsfics nnly purl of lhc nrlglnul Chinese requirement. The Chinese ure. ihereforc. expected to continue efforts to import one or two larger models either from Japanese. European, or US sources.
SMALL AND MINICOMPUTER
The Chinese huvetrong Interest in small and minicomputers for industrial contnil application* und for conventional engineering and scientific computation. This interrsl was tieurly hlghllglitrdMt nf (he Chinese computer delegation In the United Mutes3 mid has brctl rrfWlrsI In computer und test enulpmrnl imports, primarily from Japan," "The inlerrsl in minicomputers may uImi lie iiswtciatesl with classified developments of alrtxinie computing ei|uipmciH sincekinds of equipment use much nf (lie Mtmi'drcull leehnolngy and nssrmhly techniques,
Fjamplcs of small Chinese desk size mm pot en Include thendodels, first displayedhese motlcls offer cupuhllltlc* no Irettrr thun those of eurly minicomputers hulll In the USheir esternul appearance and specifications suggest thut they use much of Ihe same engineering design us early, small transistorized computers like theesk-top computers such as thend an unidentified model shown iuave hern displuyrd onrwu Externally they appear to Ik- close co|hcs of early US Digital Kiiuipmenl Corporation POP or Datu Cenend minicompulrrs hut the speciflciitlons
- sccntr-
huve been released do not permit prcclve per-forma nee comparisons.
A major source of minicomputer technolony in Ihe form of finished minicomputer models and technical assistance in engineering design and applications has been the Japanese instrument manufacturer Takcda Riken and its affiliate. Nlhon Minicomputer. These companies manufacture under license and sell minicomputer models of the US Data General Corporation. Thehich is the Japanese version of the Data Generalus been sold to the PRC on at least four occasions9 either as part of test systems orhe Chinese have visited the factories of both Japanese companies and displayed particular interest in the manufacturing methods. The strong and continued interest of the Chinese In the0 and Its potential applications suggests that the0 will serveattern for similar developments in the PRC.
I
AUXILIARY STORAGE AND PERIPHERAL EQUIPMENT!
' i
The Chinese have given little attention to improving the quality, performance, and reliability of computer storage and peripheral equipment in comparison with central processor development. This is not surprising in light of the limited number of computers in use and their predominantly scientific rather than data processing application. Effective utilization of existing computer installations, however, probably hus been hampered by the poor performance and reliability of the storage and .peripheral equipment.
The best known examples of magnetic drum und tape units used with Chinese digital computers compare In performance with models available In the United Stales during the, The largest capacity drum reportedupacltyblt words and un overage transfer time per word rjf abouthis drum has been observed only with tho ill computer at the Institute of Computer Technology. Peking. Tape units with: maximum storage cnpacillesbil words, recording densitiesits per Inchnd transfer timeicroseconds have been displayed. Assuming various recording formats and redundant recording these specification* imply tupc speeds on the order ofo AO In/s. which Is againechnology. The Chinese are heavily dependent upon foreign suppliers, mainly French, fori high quality magneticQuestions asked by Chinese visiting the United States3 indicated! lhat the PRC has not been able to solve major technical problems of quality control associated with the manufacture of magnetic tape. Possibly the only good quality tape available to military and other priority users is that supplied from foreignetter quality magnetic drum and tape units, some of which may have been imported, are believed to be; available to priority users. Those of Chinese, manufacture would be of higher reliability but' probably would not offer significant performance' improvements over those more commonly available.
The only magnetic disc storage unit of Chinese} origin has been one with theomputer system; at Peking University. It has neither been pliotographtd nor observed by US specialists, but the visiting' Chinese computer dclegution to the United3 described it in some detail. Ilixed disc unit withracks each,ecording densityn.il resembles the IBM RAM AC disc drive developed ii1 Its design doe* not incorporate the flyi: or floating head technology which is critical In ihe high performance and high precision disc drives commonly used In the West. It is a very unsophisticuted drive and easily reproducible and may lw perfectly adequate for most Immedlute Chinese computing requirements. It dries not. however,apability to build ihe more sophisticated disc drives, even types computable with US models available In the.
A limilur lack of progress ha* been evidenced in Chinese development of input-output equipment for computer* with but two exceptions, line printer* and digital plotters. Input continue* to be primarily paper tape, with few externally appurcnt differences from equipmentear* ago. Typewriter* und paper tape punchesimilar luck of advonccmcnt, und there Is no evidence of card equipment except with Imported machines. The Institute of Computereking hus conducted experimental developments of cathode-ray tube displays,printers, und character recognition equipment, but siK'h equipment has been oliscrved only at experimental Installation*.'"onsiderable progress hus been uppurenl In tbe development of digital plotter* and linene printers with speed* upines per minuteharacters per line
La
*
have been observed. These cupablliliei arewith ihose of US rrtodeh avafluble In ihe lale
Beginning with the visit of the Chineseelegation to the United States Inhere haveumber of indications that there now placing increased cmphusli on the development and manufacture of Improved auxlllury storage and peripheral equipment for computers. The delegation expressed an unusually strong Interest In the engineering design and assembly of US equipment, parttculady magnetic disc1heir detailed examination of US equipmentclearly aimed at extruding information on equipment design und layout to be used In similar developments of their own. It Is doubtful that the Chinese obtained any significant assistance In duplicating the manufacturing process for such equipment but It may have provided considerable guidance and time savings in initial prototype construction. The Increased attention given lo such equipment developments may be prompted by plans for more sophist lea led dvilian and military use of larger computer systems represented by the DJS-ll andhinese press releases of these systems have emphasized the vuricty and nnml>er of pieces of peripheral equipment installed.
COMPUTER SOFTWARE
Software development clearly lags for behind computer hardware developments in the PRC0 virtually all machines were programmed In machine nr ussembly languages. Only within theean have higher level programming language compilers been written for several Chinese computer models. Operating lystemx appear lo Ite very primitive and only one computer, the DJS-ll.enasrogramminghe only Identified group known totrong und continuing software development effort Is the Peking Institute of Computer Technology.
The major source language used wilh most Chinese computer* I*l. exbtlng In several Chinese variant* with compiler* written for several differenthe compiler for the Chineseersion of AIA70L, which was written forC computer at Ihe Peking Institute of Computer Technology, appears to be the most advanced and thoroughly developed Chinesenlike otherOL compiler. It ncccpt* some Cliinrv keysvtinb sprllcd phonetically. Other source Inngungc*
l_2
Investigated by thenclude: FORTRAN, which has been implemented at least on modeb III: COBOL: and PL/I. The predominant use of computer* for scientific and engineering problem solving has prompted Ihe Chinese emphasi* on ALGOL und this situation I* not expected to change for several years.
At iheir current stage of computer development the Chinese appear to be unusually reludant to develop more sophisticated operating system* or to apply well-known techniques for data storage and manipulation. In fact. US specialists have observed that *nme of the most expert Chinese software specialist* are not generally knowledgeable of such ba*ic concept* as job control longuuge* and memory protection techniques, which have been widely applied In thehile such concept* arc not essential to the types of computer application* now underway in the PRC, the current lack of undentanding of these concepts could be ahandicap lo future Chinese effort* to apply computer* to more sophisticated data processing and control application* In both dvilian und military programs.
The multiprogramming capability attributed to theppcurs lo he minimal. Program protection is provided only by the physical segmentation of the memory Into four blocks. There appear lo be no software features lo allow the flexibility of handling program* lhat overlap Into other blocks without occupying Iwo or more complete blocks. There i* also no evidence of privileged Instructions.
SUPPORTING COMPONENT TECHNOLOGIES
The Chinese have cleudy made the transition from transistor to integrated drcutt technology in the assembly of logic and arithmetic circuits for computers Integrated drcults maycn tried experimentally as early8 In some kinds of computingariety nf both hybrid and Integrated drcults have Ixen observed In all recently announced computer models and In puldlshed component and equipment handbooks'* For example, thick film rtmiit* similar to IBM *olid-logic-technology (SLT) type* are used in thend both diode-transistor-logic (DTL) and Ininsbtor-Iranslstor-logic (TTL1 hlpolor Integrated clrciill* with one or two logic gate* per package are used Innd In the DJS-1Circuit complexity remains at or below aboutates per chip for all Chinese blpnlnr device* shown thus for.1
Clrcult delays us short usu huve been reported for the two-gute Schottky TTl.sed In thehich Is ubout twice ui fust as circuits used Innd other Integratedodels announced by the Chinese during theho speed of the Chinese Schottky TTL circuits Is Impressive but less than half the speed of slmllur US circuits. Emitter-coupled-logic (ECU circuits-s rlsc-tlme have been reported by the Shanghai Metallurgical Researchetalb on the complexity of the ECL circuits have nol been reported but they are assumed to be no more than one or two gate devices. The combination of ECL circuit functions available In quantity pmhubly is fur too srnull for the construction of anything more than small, special purpose computing equipment. If sufficient varieties become available, however, and the Chinese cun make comparable performance Improvements In Internal memory speeds, they should be able tourge scale computererformance level slightly below that0 model, assuming computer architecture similar to that used In theind development would not be surprising within thecurs.
Bipolar TTL and DTL Integrated circuits of Chinese origin probably exist In the greatest number of functional varieties for use In computer arithmetic and logic applications, but some exumplcs of metol-oxide-semlconductor (MOS) circuits have1 also been observed. For example, gptffffffffffffffffffffffjj have experimental devices a* sophisticatedbit memoryhe Chinese have also Imported from Japan advanced Integrated circuit test systems specifically designed for MOS ond very sophisticated bipolarlthough blpolur und certainly MOS circuits probably exist In very limited quantities, the Chinese appear to be making very mpld progress In advanced semiconductor device developments. The use of these devices In special purpose; computing equipment for military applications can not be ruled out at this time.
The uvulluhllity of Integrated circuit components would notrerequisite to Chinese constructionarge-scale compulcr exceeding ihe performance nf the DJS-ll orus shown that machines such as theith mure thun three times the speed of the DJS-ll. can be built with discrete transistors using sophisticated loglcnl design, system design, and assembly techniques (seeiro high speed, parallellica Hon .circuits and system architecture of the DJS-ll denlonstrate Chinese capabilities to Implement such design techniques. However, tho Chinese have notupahlllty to supply the necessary high-speed transistors or smoll-dlameter fcrrltc cores needed In the constructionomputerhereood possibility that transistorized computers more powerful than the DJS-ll may exist In China and even predate thennouncement, although available Information does not confirmevelopment.
The cycle time or speed of ferrlte-core Internal memories of computers currentlyajor constraint to the arithmetic speeds of PRC dlgltul computers. The speed of arithmetic and logic circuits has surpassed core memory speeds, forcing the Chinese to use more compllcoted computer architectures to permit parallel memory accessing. Memory speed Is directly related to fertile core dimensions and drive-current levels; and small diameter cores and higher drive currents provide increased speed, with reductions In the core diameter providing the greatest Improvement. The smallest diameter cores in Chinese computers have outer diameters ofils,imited capability to fabricate cores as small asils probably can be credited to theithmll core the Chinese would nol be expected to achieve much bettericrosecond cycle timeblt word memory, without overiaps. oractor of two ImprovementJS-ll type of computer. Therefore the reduction of core diameters mayignificant concern to the Chinese In the development of higher performance large scale computers. Tlw use of thin film scratch pud memories already demonstrated InC. small semiconductor memories, nnd parallel system architectures probably will be continued In an effort to circumvent this
The Chinese haveudding capability to fabricate the multilayer printed circuit hoards needed in the high-density assembly of computing equipment employing Integrated circuits. Four-layer hoard* base been observed in thend. although not positively confirmed, comparable bourds probably arc also used In the. "The fabrication of five-layer boards has been accomplished by the Wuhan Institute of Muthcmutics, Computer Technology, andhile the number of layersignificant achievement, the printleast inbelieved to be very low.
11
- accoiT-
lank
APPENDIX A
CHRONOLOGY OF PRC DIGITAL COMPUTER DEVELOPMENT
FtcUity
lojiituLeof Computer Technotoaj. eking;
Peking; Wire Comncokauotu Plant
No. -
Tkouin Electronic loilru menu
Pkot Tiinghua University Peking; Radio PUnt No. 3
Futao Uoireraity
djs-i-
602
95
C--
JSfl-
-
'orM
DJS-kl9
719
of Computer Technology. CAS. Shanghai
>
Radio Plant So,
Northaaii Computer CtoUr.
IntlttuU of Computer
Technology, CAS. Shenyang Wuhao IbiUium of MatiMrruiiea.
Computer Tiehnolofy. and
Automation
AK-l*
amed-Model
Q-II TQ-6
APPENDIX B
CHARACTERISTICS OF SELECTED PRC DIGITAL COMPUTERS
Storage;
Storage:
Speed/
Kquipment/
Equipment/
odd
duply
Length
NA
ont*/
NA
pa
pm. IS cpl Typewnltr/NA
re suitor
K worda/ NA
Up*/NA Ty pewrlur/NA
Kis
bfta
r 1l. .r
K ope/
Kpa
bile
printer*/
NA
it
wpe
SA
X worda/NA
bile
K worda/ NA
prlnter/NA Typewnwr/NA
circuit
A
KN a
bila
K words/ NA
Tape/NA/NA
0 cpe
0 1pm, IS cpl
r .1 .if
1
pa,ord
K worda/
tape/
pa,
store/y
na per wordorda/
epa
cpl
A
pri word
w*.
opa/Sea/
Ka.
biU
K worda/
Upe/
printer (same
K word buffer/TM word Ihia nlaa/wU au
per word
l . orda/
er word
epe
slbode-rey.luU0 Ipa
cpfcSvNA
ka
tale
K0 pi per word
tape/SCO epe
prtateriNA
ope/NA/NA
K wofda/NA
bila
(ik ted
circuit
ojW8 ,^
Ka
K worda/
prtnter/NA
-i i
tie per word
ampleo per eeceed
Biplea per eccoed
1 !
2 nhilh
3
X 3
il
|HU|i
a ;
Original document.
Comment about this article, ask questions, or add new information about this topic: