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use the system to submit their job requests. The chief advantage of the 
system was its interactive nature - the terminal prompted the engineer 
during the submission procedure with a series of questions to which he 
responded and so prepared his job request. 
The EASY-GCARS System 
EASY-GCARS was developed in 1970 for classroom teaching at the Univer- 
sity of Toronto. An IBM 360/65 was available, but without terminal sup- 
port capbailities. It was therefore decided to develop a simplified 
request system which could be submitted as a series of batch jobs in the 
regular job stream. Since the cards had to be punched by inexperienced 
persons it was desirable to have them as simple and flexible as possible. 
Accordingly a FORTRAN program, called EASY, was developed which utilized 
the NAMELIST statement as available in the IBM FORTRAN. Each student 
was supplied with a set of JCL cards and submission instructions. 
Although not as easy to use as the GCARS II system because the inter- 
active features of GCARS II were lost, EASY-GCARS proved to be relative- 
ly easy to use by people having little previous contact with computers. 
EASY-GCARS was used successfully by students at the University of Toronto 
and by engineers attending a short course in London, England. In the 
latter case about 95% of the jobs submitted ran successfully. 
Reactions to the GCARS II and EASY-GCARS Systems 
The users of GCARS II and EASY-GCARS were encouraged to express their 
opinions concerning the advantages and limitations of GCARS and to sug- 
gest what modifications they felt to be desirable. 
In general the users appeared to be convinced that the concept of a 
computer-aided system along the lines of GCARS I would prove viable, 
although all found GCARS I itself to have some weaknesses. Those users 
which had access to the interactive terminals of GCARS II were perhaps 
more positively impressed than those whose "man-machine dialogs" were 
restricted to card input and printed output. The immediacy of the tele- 
type responses encouraged the development of a rapport between the en- 
gineer and the data. The engineers began to design the project inter- 
actively, developing it progressively job by job. 
A general consensus was reached that, provided realistic data could be 
made available, GCARS gave realistic answers and responded with some 
sensitivity to changes in factors. A number of limitations of the 
GCARS System were uncovered by the use of GCARS II and EASY-GCARS. 
Identification of such limitations led to proposals for changes. Some 
doubts were expressed about the ultimate economy of the minimum path al- 
gorithm. Proposals to improve computation times included fairly exten- 
sive modifications such as:- 
1) development of special-purpose FORTRAN algorithms, 
2) programming the minimum path algorithm in assembly language to 
optimize the program as much as possible, or 
3) combine both the above suggestions.