For the programmer, IMP forms an insulating layer between the applications 
program and the user input device. The programmer need not worry which type 
of input device the user selects, or under which type of operating system the 
applications are run. The user interface and error handling will always be 
consistent. 
Increased Programmer Productivity 
Programmers spend most of their time writing and re-writing the machine-user 
interface and error handling system, with portions spread throughout the 
applications code. IMP provides a library of machine-independent FORTRAN 77 
subroutines which provide all interface and error handling support. This 
means that application programs can usually be developed in a fraction of the 
time required by traditional methods. 
The staff of PCI converted an image analysis package similar to PACE from a 
PDP-11 to a Perkin-Elmer computer. The conversion required more than three 
person years. Once EASI/PACE vas completed, a similar conversion required 
only three person months!. 
Application-Independent Programmer Environment 
For the programmer, a single subroutine call is all that is required to 
provide the entire link between the user and the application. This isolation 
between the user interface and the application programs means that any 
modification to either section will not affect the other. 
Error Management 
All application and user errors are handled through a consistent IMP 
interface. Since error messages are retrieved from the parameter file, 
modifying them or providing them in another natural language is a simple edit 
operation which does not involve modifying any application code. 
Maintainability 
Together with reduced code size, IMP encourages the programmer to produce 
well structured code. With PCI's software development environment, system 
development utilities and on-line help and documentation generation are 
automated. 
CONCLUSIONS 
EASI/IMP is a powerful tool for the development of application software 
systems. Programmer productivity is increased by 100-500%.  Transportability 
is easily achieved resulting in wider availability of software application 
systems to end users. Because of the consistent, easy-to-use user interface, 
little or no retraining is required when upgrading hardware or when a variety 
of different computers are available to the user. 
EASI/IMP is a licensed product, ready and documented for immediate user and 
programmer training and use. It is well documented at both the user and 
programmer levels. 
With IMP as the development environment and EASI as the user interface, PCI 
has developed a powerful image analysis software system which can run on a 
wide variety of computer systems supporting several different image display 
subsystems. New computers or display devices can be added to the repertoire 
at a modest cost. 
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