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.
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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.
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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.
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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.
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