Channel, Issue No. 5

Abstract

[evdate 1991-04-15] The Hong Kong University of Science and Technology Newsletter of the Centre of Computing Services & Telecommunications Channel APRIL 1991 Issue No. 5 The HKUST Campus Network Cable Plant System - Phase I Level 152 Level 147 /148 Level 144 Level 140/42 Level 128 Level 123 Level 118 Level 113 Level 108 To staff/student quarters Inside : From the Associate Pro-Vice-Chancellor-AA 3 Campus Network Cable Plant System 7 SAS 6.06 and PC SAS 6.04 9 13/F, World Shipping Centre, 7 Canton Road, Kowloon, Hong Kong channel@usthk.BITNET

2 Channel Issue No. 4 I In this issue . . . . . Editor's Notes 3 From the Associate Pro-Vice-Chancellor-AA Waiting for the Perfect Spreadsheet 5 From the University Library - Online Catalog System Going Live 5 More on FDDI 7 Campus Network Cable Plant System - Phase I 8 End User Support - Part I 9 SAS 6.06 and PC SAS 6.04 11 IMSL Available on VAX 11 Special Purposes PC Stations Channel is a bi-monthly publication of the Ce.ntre of Computing Services and Telecommunications (CCST) of HKUST. Prepared by the Computing Information Centre (CIC), Channel provides valuable information about CCST plans, developments and services. Topics on new trends in computing technology or other related topics of interest are also included. User contributions to Channel are welcome and should be sent to the Editor along with the author's name and Next Issue : Computer Barn and End User Education The main focus will be on the computer barn and laboratories to bc set up in the campus. Computing end user education will also bc discussed. 11 department. Channel is distributed to all University members who are registered users of the CCST services. Other parties who would like , to have their names added to our mailing list for Channel may complete and return the form on the last page to the Computing Information Centre. Esther Chan, Editor of Channel C/C ccesther@usthk. BITNET

Issue No.5 Channel 3 Waiting for The Perfect Spreadsheet After reading the previous contributions to this Newsletter from several computer heavyweights, I wondered why the Editor asked such a dilettante as me to write an article. I then realised that computers, especially personal computers, have become so powerful and many application software packages so user friendly and well developed that most offices are now quite dependent on these little black boxes, most of which are not black at all. Even I, who have never developed a true affinity for computers and their esoteric terminologies and intricacies, have become more dependent on the PC in my daily work. The word processor, spreadsheet, and database are probably the most common application software packages, in descending order of popularity, found in any office. Word

processors have practically replaced the typewriter. Use of spreadsheets and databases is becoming more commonplace. My first encounter with the spreadsheet was in the dark ages of the personal computer. At great expense, I bought my fist and only personal computer, a CP/M based NEC machine with 32K memory. At about the same time, IBM

decided to go into the PC business. Overnight, CP/M machines became less popular than the plague, with very little

new software support forthcoming. I had a spreadsheet package published by a company, let me just call this company "X", which probably went out of business soon afterwards. After what seemed like months struggling through the instruction manual, which was written in a language that looked deceptively like English, I started timidly to create spreadsheets for home use, even for tasks that did not need spreadsheets. It was surprisingly easy, much easier than reading the manual. The only problem was that my computer kept running out of memory, even for relatively small

worksheets. PC application software, including the electronic spreadsheet, has since become much more sophisticated and more user friendly. Weaker products, and those with weaker marketing departments, fell by the wayside. The name "X" has disappeared from the software glossary, 'instead, several new names appeared in the market. Most of them are easy to learn and easy to use. Basic functions are similar in most spreadsheet packages. Even for the newest beginner, one can gain sufficient proficiency within an hour (if one stays away from the instruction manual) to begin putting one's newly acquired skills to slow but practical use. Soon one becomes bolder and ventures into larger and more complex worksheets, making up formulae and using cell references with wild abandon. With the graphic functions, one may even be tempted to have some fun with bar charts and pie charts. Macros, if one so chooses, can be defined to facilitate often repeated functions. With the data functions, one can sort and alphabetise columns and tables. Data can be extracted from one file or combined with another. What more could one ask for? Strange as it may seem, my stone age "X" spreadsheet had a most useful feature that many modern versions of spreadsheet do not have. I am speaking of the 3-dimensional spreadsheet. A 3-dimensional spreadsheet is quite easy to visualise. If you think of a 2dimensional worksheet as a page of a ledger, then the 3-dimensional "sheet" is a ledger book with many pages. Instead of a 2dimensional data cell, you now think of a 3dimensionaI data cube. Instead of being identified by row and column, a data cube has a 3-dimensional address, with the addition of a page index. As an example, think of the compilation of a consolidated university budget proposal. If you put one department's budget proposal on one page, then a 3-dimensional worksheet which consists of tens of pages will contain all the budget proposal records for the university. Graphically, your 3-D budget worksheet may look like this: Biochemistry 1991 1992 1993 - E &E Engr 1991 1992 1993 Computer Science 1991 1992 1993 No. of students 120 150 200 No. of staff 30 45 60 No. of PC 25 35 50 No. of ws 15 20 2.5 Example of a 3-D spreadsheet. No real data are given. With a 2-dimensional spreadsheet, one can construct a worksheet to record the same data as above by arranging the departmental "sheets*' vertically and/or horizontally in one file. The data can be manipulated by using the usual avail- able functions and techniques. So why bother with the data cube? For one thing, it is more elegant and aesthetically pleasing. But there is a more practical reason.

In the above example, one may wish to examine the budget proposal for 1991 for all departments. This can be accomplished if one can "cut" vertically into the date cube at the

1991 column and "open" up the cube at that point. The resulting sheet would have all the departments across the top and the proposed figures of each department in the corresponding columns. Then by cutting into different columns, 4 Channel Issue No. 5 one could examine budget proposal for 1992, 1993, etc. If for some reason the "No. of PC" item of each department is of particular interest, one would like to "cut"

horizontally into the cube at that row, "open" up the top and take a peek. In other words, if one could rotate the data cube about a vertical axis or a horizontal axis, one could easily view the data cube from three sides. To achieve the same results from the current 2-dimensional version, one would have to be quite a contortionist. Also, since we now have 1 or 2 megabytes inside our little desktop PC's, we should not have the problem of running out of memory as fast as I did with my 32K little black box. So what else does one want from a spreadsheet? Better graphics? More user friendly? One rarely makes use of all the available features anyway; so normally the spreadsheet programs nowadays are really quite adequate. In fact, can any spreadsheet be called perfect? A 3-dimensional spreadsheet would be quite close to the view. Any avid spreadsheet users have any suggestions or care to raise a complaining hand? Dr. Henry H. T. Liu Associate Pro- Vice-Chancellor - Academic Affairs aaliu@usthk.BITNET +!m!El 120 150 200 WIs!El 30 45 60 %LA?i&s!tftf 25 35 50 I#h!iPlf 15 20 25

Issue No. 5 Channel 5 From the University Library Online Catalog System Going Live The University Library released its Online Catalog to the university community on March 6th. Select the "Library Online Catalog" option from the network main menu to access the system, and then enter "v" to select VT100 terminal type. See the "Library Online Catalog" brochure for more details. Mr. Donald B. Wassink Sub-Librarian Ibdonw@usthk.BITNET More on FDDI FDDI Devices Before we go straight into possible implementations of the FDDI network, perhaps it would be beneficial if we first discuss the devices in a FDDI network. The FDDI standard defines two types of nodes (any device attached to a network is known as a node): stations and wiring concentrators. Stations refer to any addressable node with processing power such as workstations, PCs or even central computers. The wiring concentrator (CON) provides additional connections for the attachment of multiple nodes to

the FDDI ring. Stations can be further divided into Dual Attachment (DAS) and Single Attachment (SAS) stations. The CON can also be either single attachment (SAC) or dual attachment (DAC). Having defined the two types of devices, we can have a look into these devices in greater details. SAS permits access to the FDDI ring via the CON, and as its name implies, SAS is attached to the FDDI ring at a single connection point, hence it does not have wrapping capability (which we had discussed in some details last time) in case of a station or fibre failure. Despite this handicap, SASS are very important devices in our implementation (if you can be patient and bear with me for a while, the reason is almost self-revealing). DAS is able to connect to the primary and secondary rings of the FDDI dual ring, allowing a station to access the dual ring architecture of FDDI. However, it may be to your surprise, you will not see many of these devices in our implementation (again please bear with me for a while).

The wiring concentrator (CON) allows the attachment of multiple SAS or DAS devices to the primary (or optionally, secondary) ring of the FDDI network. The single attachment concentrator (SAC) is connected to the FDDI dual ring at a single point and thus has no wrapping capability. The dual attachment concentrator (DAC) connects to both the primary and secondary rings of the FDDI dual ring and provides the wrapping capability. Unlike concentrators found in other networks, the FDDI CON is an active device that can actually control the physical topology of a network. The CON is able to reconfigure the network as necessary by inserting or removing devices connected to it.

6 Channel Issue No. 5 The FDDI Dual Ring The most logical implementation of a FDDI network would be to have optical fibre cables going to every comer of the campus, and insert dual attachment stations in various locations. Well, good try but not quite right, even if the cost

factor is not taken into account, there are also technical reasons not to have this implementation. Dual Attachment station (DAS) - FDDI Dual Ring station Fig. 1. A FDDI dual ring consisting of eight DASs. Faulty station G 1 F E Ix/ Wrapping occurs Fig. 2. Faculty stations, D and H, are masked and two dual rings are formed. Consider for example, a FDDI ring consisting of eight DASs (Fig. 1). Under normal conditions, the dual ring should per- form nicely and you would be very happily typing your keyboard or working with your mouse. But what if when two DASs (these may be two workstations) simultaneously went out of action? This should not be an exceptional case with a large network. So, now consider Fig. 2, when stations D and H are out of action, the FDDI ring would undergo its wrapping functions and mask out the faulty stations. As a result, we end up with TWO networks instead of one, which is highly undesirable. And the worst may happen that a number of isolated networks are running wide, definitely a nightmare. Furthermore, with this simple dual ring implementation, the FDDI network will be disrupted with every

addition or deletion of workstations, another highly undesirable situation. To avoid the above situation, we have adopted

the Dual Ring of Trees approach in our implementation. The Dual Ring Of Trees A simple form of this implementation is illustrated in Fig. 3, which shows how concentrators are connected together in a dual ring. The FDDI dual ring backbone is formed by three DACs, to which SACS are connected. Each DAC is able to accommodate a number of SACS. Each SAC in turn provides connections to other SACS and nodes. A tree like structure is formed in this way. When a SAC (or a node) or its connection wiring is not functioning properly, it will only affect the nodes attached to it. When a DAC is found mulfunctioning, the other two DACs will wrap and reinitiate the ring. Furthermore as the campus backbone is hidden in the structure of the academic building, accidental damages to the cables would be highly unlikely. Reliability of the network is thus ensured. In ad- dition, this structure offers flexibility of adding and removing stations without disrupting normal operations. With this implementation, trees of concentrators can be connected to the

dual ring, providing connections to the stations on your desk tops. DAC DAC FDDI Dud Ring Backbone

SAC A' SAC L SAC Fig. 3. The Dual Ring of Trees Topology. Now perhaps you can see why SAS is a more popular device in our implementation than DAS.

Issue No. 5 Channel 7 Campus Network Cable Plant System - Phase I The campus network took the basic appearance of the Dual Ring of Trees implementation but with a slight difference of ingredients. What this means is that we will not be routing the optical fibre cables to your table tops (sorry to disappoint you), but instead the optical fibre will be going to a location (known as wiring closet) near you, and from there a web of Ethernet cables will deliver the badly needed computing services to your finger tips. The general appearance of the campus network would look something like fig. 4. You are probably wondering what Level 128 means. Well, actually this corresponds to the height from sea level, and don't worry about it, you probably won't meet it again in your life, as by the time you move into the campus, the Level xxx will be replaced by something wonderful like l/F. There is another thing I would like to draw your attention to, if you look at this figure, you will notice that the optical fibre cables go through small dots. Actually each dot rep- resents a small equipment room known as wiring closet (WC), and it is in these wiring closets we will install all our networking hardware. In our design, we have classified all WCs into three different distribution types, according to their importance to the net- To staff /student quarters Level 152 Level 147 /148 Level 144 Level 140 /42 Level 136 /37 Level 132 Level 128 Level 123 Level 118 Level 113 Level 108 wiring closet location Floor outline (hypothetical) Fiber Optic Cable Fig. 4. The Campus Network Cable Plant System - Phase I.

8 Channel Issue No. 5 work. The most common is known as Horizontal Distribution Frame (I-IDF), these are all the wiring closets which

supply services directly to the users. The second class is known as Intermediate Distribution Frame (IDF), and these provide the connection between Main Distribution Frame (MDF) and HDFs, sometimes, IDF also has the functions of HDF. The last class, of course is MDF. MDF is used to provide a connection between IDFs and the computer systems. Our network, like many others, has just one MDF and

many IDFs (one per floor) and HDFs. Perhaps the best way to start would be to look at where all this begins. Naturally all computing and networking services originate from the computer room. In our case the computer room is located at level 132, and right next to the

computer room is our Main Distribution Frame (MDF) at WC 34. If you look into the drawing more closely, you can see that all the optical fibre cables originate from this point, and branch out to each floor of the building (which is very logical as WC 34 is our MDF). Perhaps an example could illustrate our philosophy more clearly. Consider a user located at Level 144, the IDF of this floor is located in WC 6, so we can see in the drawing that an optical fibre cable is going through a riser (which look similar to a lift shift but a lot smaller) to WC 5, then through the

ceiling fibre cable trunking, this cable will arrive at WC 6 (actually, WC 6 together with other IDFs contribute the dual ring backbone). A bunch of fibre cables would then branch out to all the HDFs that being supported by this IDF, and one of them would be WC 8. As far as the fibre network at this level is concerned, it stops right here, all the rest of the campus network will be superimposed by a maze of Ethernet cables. So, if we take a look at the area around WC 8, we can see (a pair of X-ray eyes would certainly be very helpful) a web of Ethernet cables leaving this wiring closet, going through the underground trunkings to your very desk top. There you see, our Campus network is actually a combination of two networks: an optical fibre backbone and a very

complicated Ethernet network which take the much needed computing services to the tips of your fingers. Mr. Joseph Pang, Senior Computer Officer Systems Engineering ccjoseph@usthk.BITNET

End User Support - Part I Editor: The CCST End User Support mechanism is explained to our users in two parts. This article is part I, on user problem handling. Part II on end user education will appear in the next issue. Computer User Support is deemed to be one of the most critical and demanding activities in the area of end user computing (EUC). In simple terms, computer end user support means providing information or computing resources to end users so that they can complete their tasks or assignments in an effective and efficient manner. Such re-

sources include hardware, software and, most importantly, consultancy services. At HKUST, CCST's Computing Information Centre (CIC) is responsible for the said computer user support. Generally speaking, the following major services are currently being provided by the CIC team: (1) Help to identify the end user's information processing needs and try to satisfy them by pro- viding appropriate computing resources. For example, coordinate with the System Engineering (SE)

team to install new computers and printers. (2) Assist end users to evaluate their software requirement. Liaise with software vendors for software

testing, acquisition, and finally, software installation. (3) Provide computing consultancy to our end users. This includes helping the end users to solve their daily computing related works, recording hardware defects and reporting them to SE team for prompt action, instructing and explaining software applications, and monitoring the University's computing

environment for general user enquiries. Case Handling Procedure Whenever users have difficulties in using the computing facilities offered by CCST, users can seek assistance from CCST by calling the user support hotlines. A member of the CIC team will first identify the nature of the problem and handle the case in the following manners: (1) If the problem falls into CIC's expertise area, CIC staff will try to solve the problem with the users

Issue No. 5 Channel 9 concerned as soon as possible, through phone or on the spot, to explain to the users the case and close the case accordingly. More complicated problems will be taken back to the Centre for further analysis and returned to the user afterwards. (2) If the problem turns out requiring other expertise, for example, a system level problem or a hardware oriented engineering problem, CIC staff will record the case, inform users that the case have to be referred and refer the case accordingly. For examples, information system problems to the In-

formation Systems (IS) team and hardware problems to the SE team. Whatever the case, CIC staff will continue to liaise with the problem solver and the end user throughout the whole problem solving exercise. (3) Occasionally, end users may approach non-CIC staff for problem solving. Should such situation arise, staff being consulted will depending on the nature of the problem, handle the case by themselves and inform their CIC colleague as appropriate or pass it along to CIC for action. Case Management Every case handled will be recorded and reviewed by the CIC team. A small computerized system is used to help achieving this purpose. Regular meetings are also held to analyse odd cases as well as recurrent cases. Conclusion of these meetings will serve as a vital input to Centre's future policy formulation and strategic planning, especially in the areas of user training and service provision. Characteristics From the above description, one can see that CIC is the front-end of CCST, an interface between the end users and the Centre's expertise. To the end users, CIC is the contact point for support and services. When seeking help, users are not required to bring along their problems and knock on every CCST staff's door, digging out who shall solve what. To CCST staff, CIC members help to filter out most problems, categorize and redirect the rest to the appropriate experts, thus saving these staff's time and enabling them to concentrate on their specific duties. User Support Service Contact Point For reference, the following contact points/hotlines have been assigned and publicized for end user support purpose: General End User Support Coordinator: Tony Chan 302 1476 User Support Consultant: K K Tam 302 1578 Scott Cheung 302 1760 Besides, CCST also provides an Electronic Help Box. Users can make use of this facility to seek for consultancy services. Electronic Help Box's address is CCHELP and can be accessed by electronic mail. By the User Consultation Team SAS 6.06 and PC SAS 6.04 SAS (Statistical Analysis System) Version 6.06 has been installed on USTCC1, a VAX 3800 machine. The software will be moved to a VAX 4000 machine in the near future. In this article, we are going to outline the features of SAS and give you a short account on the functionalities of the specific modules that CCST has acquired. The SAS system is a modular, yet integrated software for data management and analysis. It has full capability for developing useful applications complete with data entry, editing, and retrieval. A comprehensive set of data analysis tools is available for statistical analysis, modelling and forecasting, mathematical programming and operational research studies. The outputs from analysis can be presented in a variety of graphical forms.

Users can access various functions of SAS through a set of menus. For users who would like to develop application systems, SAS has its own programming language and also support the industrial standard database language SQL. CCST has acquired and installed eleven SAS modules. They are: 1. BASE SAS/BASE is the foundation of the SAS system, sup- porting data management, basic statistical analysis, and report writing. Release 6.06 introduces the concept of engines, a set of routines for processing non-SAS files as if it were SAS data sets. That is to say, SAS can now support many different physical file formats.

10 Channel Issue No. 5 2. ASSIST SAS/ASSIST is a task-oriented, menu-driven interface to the SAS system. It allows users to work on most of its features without knowing the syntax of the SAS language. Each menu screen is powered by common-sense keywords. Besides, a brief tutorial on how to use the SAS system is also incorporated under SAS/ASSIST. 3. AF SAS/AF is an interactive tool for building applications and designing user-friendly front-ends to new and existing applications. In fact, SAS/ASSIST is developed using SAS/

AF. Users can use S AS/AF to - develop menu-driven and fill-in-the-blank screens for applications; - give users hints, reminders, and documentation at any point in an application; - provide customized computer-based training. 4. ACCESS SAS/ACCESS provides a direct link between the SAS sys- tem and a wide variety of popular database management systems such as IBM's DB2, Oracle Corporation's Oracle, and Digital's Rdb/VMS. For our case, we have installed SAS/ACCESS interface to Rdb/VMS. 5. CONNECT With SAS 6.06 on the VAX and PC SAS 6.04 on PC, a user can make use of SAS/CONNECT to distribute SAS processing in a client/server manner. Distributed processing facilitates effective use of computing resources. SAS/CON- NECT provides the capabilities for remote processing, file transfer and local graphics display. 6. ETS SAS/ETS supports econometric and time series analyses for forecasting, financial modelling, and business planning applications. It includes capabilities for time series analysis,

linear and non-linear systems simulation, loan amortization, depreciation, and row-and-column financial reporting. 7. FSP SAS/FSP provides capabilities for interactive data entry with table look-up and cross-field validation, data editing and query. Data entry screens can be designed to simulate business forms or laboratory logbooks. A letter writing facility

is also available for mail/merge applications. 8. GRAPH SAS/GRAPH offers high resolution graphics for business and analytical applications. Users can produce charts, scatter plots, contour plots, three-dimensional plots, bar graphs,

maps and a variety of other graphic forms using a broad selection of built-in fonts and patterns. It includes device drivers that support most graphics terminals, printers and plotters. 9. IML SAS/IML is an interactive matrix programming environment for advanced statistical engineering and mathematical applications. The software gives users the power of built-in matrix

and vector operators such as inverse and eigenvalues. 10. OR SAS/OR provides capabilities for operations research, project management and decision support. The software handles assignment problems; performs critical path analysis and linear programming; determines minimum cost flow, maximum

flow, and shortest path for a network; and supports graphic display of network models and Gantt charts. 11. STAT SAS/STAT provides capabilities for producing simple descriptive statistics, advanced regression, analysis of variance,

categorical data analysis, multivariate analysis, cluster analysis, factor analysis, discriminant analysis and survival analysis. SAS 6.04 for PC Besides SAS 6.06 on the VAX, CCST has also acquired the PC version of SAS. Seven modules are available, namely BASE, AF, ETS, FSP, GRAPH, IML and STAT. The latest PC version, V6.04, features the same functionality as SAS 6.06 on VAX. Users who would like to use the PC version of SAS should contact the User Consultation Team. Distributed Processing with PC SAS 6.04 and SAS 6.06 on VMS In this section, we are going to describe how distributed SAS processing can be accomplished in our implementation. With SAS 6.06 on USTCC1 and PC SAS 6.04 on PC,

SASKONNECT establishes the link for remote processing, file transfer and local graphics display.

Issue No.5 Channel 11 For remote processing, a user can develop and test a program using PC SAS and then, while still remain under PC

SAS, remote-submit the program to USTCC1 for processing of large data sets stored over there. For graphics processing, one can execute the graphics program on the remote

host and display the graphics on the local PC. Furthermore with the file transfer capabilities, users can easily move the graphics image from the host and save it locally on the PC, All the post-processing jobs such as graphics replay, print- ing and plotting can all be done locally without taking up any resource on the host side. Without SAS/CONNECT, using PC to emulate VT-100 or VT-220 type of terminal will not be able to support graphics outputs from the host. The use of additional graphics terminal solely for the purpose of graphics display may not be

justified for most cases, SAS/CONNECT is undoubtedly an appropriate solution for many users. Training and Support CCST plans to offer an introductory SAS course to staff and students after we move to the campus. In the meantime, for those users who need assistance in using SAS should contact the User Consultation Team.

Mr. K. K. Tam, Computer Officer c/c cckktam@usthk. BITNET

IMSL Available on VAX The IMSL Complete Libraries Group will be installed on a new VAX 4000. This is a set of computational subprograms written in FORTRAN. The IMSL Libraries include the following three products: . IMSL MATH/LIBRARY Version 1.1 - general applied mathematics . IMSL STAT/LIBRARY Version 1.1 - statistics . IMSL SFUN/LIBRARY Version 2.1 - special functions. Interested users may contact the User Consultation Team for the command procedures to access the libraries. Special Purposes PC Stations Two PC stations have been set up in Rm10A on 5/F. These PC's are open to all university members. One of the PC is equipped with both 5.25" and 3.5" disk drives for medium conversion. The other one is a PC 386 with 4MB memory, 40MB harddisk and a VGA monitor. The following software have been made available for testing on this machine. Academic software : Turbo C Turbo Pascal Turbo Debugger Quick C Quick Pascal Microsoft C Microsoft FORTRAN MathCAD Application software : Microsoft Word for Windows Microsoft Excel for Windows Microsoft Windows Harvard Graphics ChiWriter To display a complete list of software available for testing, choose the User Menu option from the network main menu. New software will be added to the list upon arrival. These software will be installed on our campus network for the use of staff and students. Users are strongly encouraged to play with and test the functions of the software.

- 12 Channel Issue No. 5 . CCST Contact Points Ext. E-mail User Consultation Coordinator - Mr. Tony Chan - 1476 cctony Problem Reporting E-mail Account CCHELP - UNIX support = Mr. David Yeung - 1538 Telephone Services Coordinator - Mr. Scott Cheung - 1760 For users to send in their problems and difficulties via e-mail. A consultant will respond to messages sent to this account as soon as possible. . ccdyeung

ccscott Suggestion E-mail Account - CHANNEL - For users to send in their queries, ideas, suggestions and comments concerning services we provide. A consultant will respond to messages sent to this account as soon as possible. Training courses registration - Mrs. Anna Ho - 1570 ccanna

Requests for Computing Resources - Mr. Danny Tang - 1512 ccdanny

Centre of Computing Services and Telecommunications. . . .

Phone address Director Dr. Wm. Max Ivey 1440 CCmax Mgr. Systems & Operations Mr. Lawrence Law 1442 cclaw Mgr. Information Systems Mr. William Tung 1443 ccbtung Mgr. CIC Mr. Danny Tang 1512 ccdanny Mgr. Systems Engineering Mr. Michael Tang 1533 ccwctang Editor of Channel Miss Esther Chan 1537 ccesther FAX 736 7088 Dialup 736 9181 Computer room 1494 SE workshop 1535 The telephone extensions are (852) 302-xxxx. The BITNET addresses are E-mail address@usthk.BITNET E-mail

Channel Mailing List A mailing list is maintained for the distribution of Channel. To be placed on the mailing list*, fill out this form completely and mail to the Computing Information Centre, CCST, 13/F, World Shipping Centre, 7 Canton Road, TST, Hong Kong. Please print clearly. q Add my address to the mailing list 0 Address change (write new address below) 0 Remove my name from the mailing list Name : Organization : Address : *Registered users of the CCST services are placed automatically on the mailing list. 期待著一個 完美的電子試算表 讀過前幾期數位電腦重量級人物的投稿後，我奇 怪本刊編輯為何會邀請我這個電腦造詣如此粗淺 的人撰稿，我然後醒覺到電腦尤其是私人電 腦已愈來愈强勁，很多應用軟件也已開發得 很好，而且日漸易學易用，致使現時大{????}鷟鴗{????}室己頗依賴這些'小黑箱'了。〔今天多半這些 '小黑箱'再已不是黑色的了。〕就是我這個從 未其正愛上電腦及其深奧術語和複雜事物的人， 也在日常工作中愈來愈依賴私人電腦。 在任何一個辦公室裏，最常用的應用軟件種類依 次是文字處理、用子試算表及數據庫。文字處理 軟件己實際上取代了打宇機，而試算表和數據 庫也逐漸受到廣泛使用。 我最初使用試算表時，私人電腦的發展還處於其 '黑暗時期'。我花費不少買了我的第一部，也 是唯一的一部，私人電腦。它是運行CP/M操作系 統的NEC 32K記憶量私人電腦。差不多同時，IBM 公司決定開拓其私人電腦生意。一夜之間，CP/M 電腦鑾得比黑暗時期的瘟疫更可怕，只有非常小 量的新軟件支援。當時我有一個由某公司〔就叫 它'x公司'吧〕發行的試算表軟件，這間公司 大概不久後使倒閉了。我千辛萬苦才掯完那本使 用手冊，裏面所用的所謂英語似是而非。我戰戰 兢兢地開始建立一些私人用的試算表，儘管我那 些事務根本就毋須使用試算表。出乎意料地，試 算表很易用，比閱讀手冊輕鬆多了。我唯一的困 難是，即使我的試算表小型得很，我那部電腦的 記億體仍為不敷應用。 私人電腦應用軟件，包括電子試算表，已比前精 進得多，也日益易學易用。質量較差的和推銷不 力的產品受到淘汰，' 公司'早已從軟件詞彙 中消失，取而代之的是市場上新湧現的名字，這 些新軟件多是容易上手又方便使用的。大{????}鷒{????}算表軟件都有相若的基本功能，即使初學者也準 會在一個小時內取得足夠的掌握去把新學到的技 術緩慢地套入實際的應用上如果他不去翻閱 使用手冊的話。 用戶很快便會大著膽子肆意地建立公式與及使用 單元引用，闖闖更大、更複雜的計算表。試算 表的繪圖功能使人對倏形圖及圓形圖躍躍欲試， 有些人事選擇定義宏指令來幫助執行重復使用的 功能，而試算表的數據功能更能讓人把行和表分 類及以英文字母排序。數據甚至能從一個文件抽 出，再套入另一文件中，用戶乎愎何求？ 可是，奇怪得很，我那石器時代的'X '試算表 有一項極之有用的特點是許多現時的試算表軟件 所不具備的，這就是三維試算表了。 三維試算表其實不難想像，如果你把一個二維計 算表想像為分類帳中的一頁，那麼，三維計算表 便是一本有多頁的分類帳簿。你可把它想像為一 個三維數據立方體，而不是一個二維數據單 元。一個數據立方體具有一個三維地址〔多了一 個頁索引〕，而不是單由列和行來標示。我以製 作一份大學財政預算匯報建議書為例說明一下， 如果你將一個部門的預算建議放於一頁上，那 麼，一個有數十頁的三維計算表便包含整間大學 的所有預算建議記錄。在圖表上，你的三維預算 計算表如下： 生物化學糸 電機及電子工程系 計算機科學系 學生數目 員工數目 私人電腦數量 工作站數量 三維試算表範例資料純屬虛擬 通過二維試算表，用戶也能建立一個計算表去記 錄上述的數據，他只須把各部門的計算表直排 及／或橫排於一個文件內即可。用現有一般功能 和技術便可處理上述數據了，我們還用數據立方 體幹嗎？ 原因之一是，三維試算表較美觀，但它還有一個 更實際的優點。 再說上面的例子，用戶或想查看1991年度所有部 門的預算建議，他只須在處於'1991年'行時把 日期立方體縱向地'剪'出來，然後即時打開該 立方體。所得的計算表會在上方顯示所有部門的 名字，並在相應行上顯示每個部門的建議數字。 接著你大可'剪出'不同的行，查看1992年、 1993年的預算建議。如果用戶想看看每個部門的 私人電腦數量，他亦可在處於該列時橫向'剪 出，，一個立方體，再打開來瞧瞧。換言之，如果 用戶能倚著直軸或橫軸來旋轉數據立方體，他便 能容易地從三面探視該數據立方體了。 要在現時使用的二維試算表上取得相同的效果， 用戶必須能像柔體表演員一樣善於扭曲身體。此 外，我們現時的桌面私人電腦已有1 兆或2兆字 節的隨機存取存儲器〔RAM)，應該不會像當年我 那32K'小黑箱'那樣快便記憶體不敷應用了。 用戶對試算表還有何求呢？更佳圖像？更易學易 用？根本就沒有用戶會用盡所提供的各項特點， 所以現時的試算表程序已可算足夠應付所需。究 竟有沒有盡善盡美的試算表呢？三維試算表也許 會比較接近完美，衝勁十足的試算表用戶們又有 何高見？有何申訴？ 劉信德博士 協理副校長〔學術〕 〔朱少冰譯〕