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IDPF IMPLEMENTATION EXPERIENCE 
IDPF has been interfaced to two models of analytical stereoviewers. 
The first plotter was the National Ocean Service Analytical Plotter 
(NOSAP) which was built in the late 1970's. The computer controlled 
facilities for this plotter include movement of 2 stages, lighted 
panel of 64 switches, 2 hand wheels and 1 foot wheel. On-line 
graphic output is provided by an attached flatbed pen plotter. The 
plotter does not have built-in computing capabilities and relies on 
the IDPF control computer for this resource. The second type plotter 
is an IDPF/PWS1 which was built in 1988. The NCD possesses five such 
plotters. All hardware functions of this plotter are computer 
controlled. Built-in dedicated microcomputers service the plotter 
computing and hardware control needs. Both models were built by 
Ottico Meccanica Italiana Corporation of America to meet NOS 
specifications. It is worthwhile to point out that the two models 
represent completely different technologies and functional 
capabilities. IDPF was built, tested, and implemented first on the 
NOSAP device. The IDPF/PWS1 was built to conform to the previously 
mentioned interface standards. Two months following delivery, the 
viewer was completely integrated into the IDPF environment and was 
successfully performing all intended functions. 
CONCLUSIONS 
There are numerous motivating factors for striving towards hardware 
independence in automated systems. The experience and results 
attained in building the IDPF, and achieving hardware independence, 
was rewarding and valuable. There have been significant savings in 
system development and maintenance cost. Heavy investment in 
software development is now adequately protected. Benefits from 
continuous improvements and innovations in supporting technologies is 
secured. The need for extensive training as new equipment is brought 
on-line, and the personnel anxieties that usually accompany it, are 
now greatly reduced.