Document 6521989
Transcription
Document 6521989
Why the SAS+ System for PC? Carl Wells - New Vision Protocol To those of you that regularly use your PC for your clerical activities, at first sight this may sound like "a sledge hammer to crack a nut". If, like me, you started by developing SAS on a large mainframe then the idea of shoe-horning SAS onto a PC does not sound a very good one! After all a PC is for memos, jotters and word-processing, isn't it? Hold on a minute! If your mainframe link is Time Sharing Option and to make contact you need to be working in the middle of the night, because the chances of logging on in the morning are zero, then there must be a better way of progressing your development programmes. Do not think that PC SAS is going to solve all your problems and make you fully independant. You are still going to need your Main-frame when it comes to live running against large Production files and dynamic corporate data bases. But for developing your programmes and suites PC SAS really has a whole lot going for it. Response appears lightning fast compared with a dumb terminal and since the system uses exactly the same 'C' code to process the SAS statements we can be sure that there aren't ~oing to be those odd quirks and glitches that often come when transfering code from one environment to another. Once in SAS on a PC then you wi] I forget about your environment and get down to coding just as you did on the main frame. without the weekly billing for CPU usage! So where are the problems? The first is administration, persuading those who control th~ cash that it really jg a good idea to spend money on a PC license to release main frame capacity. There is going to be a breakeven point. and if you are going to dedecate your PC to runnin~ SAS against the cost of a TSO terminal similarly used then the PC wins hands down. Its no good thinking of buying a License if you are only going to use it once a month. The SAS Instjtute will not mind. but your accountants will. Another approach is to look at the local useage of say ten terminals and present a scheme for halving th e number of TSO links and replacing them with PC SAS which wil 1 make you "Flavour of the Month" within your organisation. SEUGI931 739 ~~~~=~~~·~~~~;::»:~2:;-:<-~~::;-~-:::'.{'-:::-':·:-- -.,-- 1., Another problem is hardware. If you are wondering whether your ancient PC XT can be pressed into service, forget itl The same applies to the less ancient 286 based machines they are just not up to it. The first PC machine that I used SAS on was an XT, but I would rather spend my waiting time in other ways. There is a minimum configuration, and SAS will run very happily on a 386SX with 8 megabytes of memory and 50 megabytes of available hard disk space. In fact it is that very configuration that is producing this paper. Anything bigger than this, or faster, and you will be "cooking with gas" as is said. Windows 3.1 or OS/2? Well it depends on you. If you are already familiar with one system, then I suggest you stick with it. I personally have not found it easy to switch between OS/2 and Windows. I know that they appear to be very similar, hut I was ~ushed back to Windows because the packages that I required were not available under OS/2. So I personally prefer Windows. it fits in very nicely with the other things that I want to run. and I can move very easily from one to the other. I have installed SAS under OS/2, worked with it without any major problems. but like I say, all my other work is normally in a Windows environment. so working with SAS under Windows has a nice comfortable feel to it to me! The SAS Institute are going to make available a Windows NT versjon. and if Windows NT meets its specification then we should have overcome a lot of the present processing problems. with the promise of true multi-processing. I think that this is a while away yet for most of us though and I am afraid that there wi) I be cunU me prob I ems tha t need to be ironed out before everyone wi II feel happy using it. So don't wait in hope start with Windows 3. 1 . I said there were problems - don't let SAS Institute kid you that installation js easy! Like any major system installation it needs to be carried out with care. The respect that would be considered when inRtalljng on the main frame in some ways applies to the PC installation. I'm not saying that you cannot instaJ! it from the manual but it is much safer. easier and controlled to have someone by your side who has done it all before. I I'm sure that a.t least in part l i t is the reassurance and support that an 'outsider' gives, bllt also it hP.ilps to foclls the organisation on the fact that something important is happening. You are less likely to have interruptions and distraetions if YOll have a eonsultant there than if you are trying to grapple with i t on your own. "Oh! he's playing with his computer again'''. is an an all too familiar problem. Whilst your consultant may not he familiar with al I the problems of compatiabiljty that you SystAffi throws IIp. will have the training and the baeking of the SA'S Institute. and also the contacts to solve problems spee(jj ly. SEUG932 740 r;%"'-1;:-,",,~~~~~~v.~,.;;:;-.c~~~~0:'~,-'::~-"-:''''''~~-:'.":---.-': i Don't be over ambitious. When you are installtng SAS on a PC for the first time, then start with SAS/BASIC and get that working first. I'm talkinR to you as SAS developers and therefore you will be wanting to produce tailored SAS/ASSISTANT and SAS/AF bases. No probJemL But do things in an orderly way. Give yourself time to settle down with the files and sample SAS programs at first. These are the key to success. there is no need to reinvent the wheel, you will find examples of most of the procedures that you need. Fol low these and modify them carefully, one step at a time, and you will be rewarded with quick and accurate results. I personally found the earliest problems that I encountered were about accessing files and finding the call paths for them. ( where Rre the little beasties?). Easy you say? Not when you are not sure of their DOS names! This is an area wh~re your conRultant can take you on a guided tour to familiarise your with the way SAS looks at files and names them. It certainly smooths the path when i t comes to handl ing the multiple files in an AF appJ ication. It is all very well having a system that is tran~ parent to the user. but jf something goes wrong then YOll need to be able to get at the bits - or 'know a man who does'. Most of the 'goodies' that SAS has availahle can be loaded PC. But beware, :i t does use a great deal of hard d i Sf' spar·e. Fifty me~abvt.es of ~p8('e is not an unusual requirf.'ment. and even wi th just BI\SIC SAS you will \,'ant to han-' 1 \venl:m(-'gab~lt(~S avail3ble. on to a If 'lOll hav!" the option than using a removabJ,~ hard dis.' s t t- m ha. s a ! 0 t 1i 0 j n ~ for it. \~ 1. t h abo 0 t 8 b 1 e . n·: m0 \' r1 hIe h a I'. j dise loaded with your SAS sllitf~. you have a confi11lration t.hai is splf-cont.ained. a.nd as St'('ur~~ as :'{Oll can h'ish for. It can also be personalised as a system and also used with other harrl~"ar"~ contLg'ura.tions. Backups ar{' simnle to produce and iti~' also simnl0 to develop Generation techniques that pnahle you to (.l8c'k-iracK throu£'h your (iEwelopmenl' process. I have used both removahlfe disc units and removal-de drivp units and found them both acceptable and reliable. Although obviousLy the Bernoul i Box type with a removable disc ~ives you more flexihj lity jn terms of stora~e. There are a number of reli~ble units on th~ market such as the Cristie mach 40. which wjI 1 aive you some 11 megabytes of (l'isc "'pact'. You then ha.v p thaI: nice warm fef'! in>:;. that once the di!1c is jn your pocket. no (m(~ CHn I.nnq::JI'·r ~'ilt.il :.-"our pr()!:!!~~m'':' or vour data. ThC:lt!8 8omf"'thirH~ that \'(11.1 ",~nnc>i. he sure of \'I':ith a~ly :::;hllred system (hU'~s. \·iru,-;ps and ha"i;f'T'S), ~w 741 ! " .'.: This is not the place to examine the merits of the various subsystems of SAS, you will obtain that information from the specific papers at this conference. In any case that is not relative to the operating system. There are however constraints that you will not have encounted when using the mainframe. Once underway then is usually a need to produce hard copy, or film depending on what it is that you are developing. On the PC the sam~ options are available as on the mainframe, but the same expertise is not. If you have centralised printing/graphics facitities for the mainframe. then it is merely a case of sending you output file to the appropriate output stream and at some stage the print/picture will appear in your pidgeon-hole. However with most PC installations you are on your own, and the ugly word 'drivers' comes into your vocabulary! Many of the difficulties come from printers and plotters whose software is not compatiable with the data stream that is coming from the PC. The firms that produce printers and plotters try to have available drivers that will convert any data stream to the required format, but often say that it is up to the software manufacturer to mainain compatiability. Poor user! You become 'piggy-in-the-middle' with a system that will not produce results. The earlier you find this, the Jess the problems are likely to be hurtful to you and your system. The most satisfactory answer is to link up with someone from the begining who understands the configuration that you have installed. or are about to install and point out any likely pitfalls. Whilst some of this is highly technical, the requirements are usually very simple. once you know what they are! For instance. "Can we procude this screen on this plotter?" If you are the sort of developer who uses 'C' language and delights in creating elements which are not available at present in SAS then the PC version is a marvellous vehicle for your development. You do need to have a reliable, fast linker but apart from that. it is very comforting to know that you have only yourself to blame for any crashes that occur, and no one else is going to suffer from your mistakes. Computer Centres usually frown on developers who code in this way that are not part of their team,and so will not approve of these developments on a main frame. The Windows version of SAS is now firmly established. and PC SAS has been around for several years under OS/2. Mark Cates, Manager of the PC Host Department 8t SAS Institute has produced an excellent paper giving a detailed description of the similarities and differences between the SAS system under OS/2 and Microsoft Windows. Release 6.08 is now available for for a Windows 3.1 environment and shows improved performance relative to 6.04 for DOS applications. Much better use is made of memory, with· the extended memory bein~ addressable up to sixteen megabytes. SEUGI934 742 What of the future? Well, everyone is lhokin~ towards Windows NT. This will give a 32bit operatin~ system with what promises to be a more robust environment. and a doubling of operatin~ speed. But the real benefit appears to me to come from the promise of a true multi-tasking environment allowing both SAS software and other applications to run on the same PC at the same time with no degradation in operating speed. "Simu]t3.neously without sacrificing performance". The worry that T have is that we are moving into a networking envir0nment and are so going the ftiJ I circle in terms of problems of access and secur i t y - "Ah we 11 I that's progress! SAS SAS/AF SAS/BASIC SAS/ASSISTANT SAS/CONNECT rp~istered trademarks of SAS Institutf~ Inc .. Can' Nt: USI\. are the Referred to in this naper and further reading :rnmparina the SAS svst~m under OS/2 and Whi(~h is ri.l?"ht for Y01],? Mark W CateR SAS Tnstltute Inc. neflni.n~ SAS ~i~rosoft ~lndows. a desktoo Si:rategv eat ions vol XVIII No 4 C(HJ1/lHWi SAS/CONVECT Software: Server Software for a successful desktop SAS Communications vol XVIII No 4 straie~y Object-Oriented Programming brings benefjts to the SAS Deva Kuma - D i n~ctor of Dj sp I ay Product s SAS Instjtute Jnc. SAS Communi('aUons va) XVIf! No 1 ~vstcm Carl Wells is a SAS Consultant wjth New Vision Pr':)tocol 154. All es tree La ne. DERBY De22 2,TY. Eng I and. 0332 :>f1fH 11 S HI" lS a (~haI'tered EnilineE'r. a Mpmber of the Jns!itui:iol1 of FIe e t riC' a I F n g i 111''' e r s. and a 1-1 em her 0 f t h f> Br i t i <:; h (~o mput f' r So('iety. \ SEtlGI935 743