In 1985, the company was the sixth largest in the minicomputer sector, with estimated revenues of US $564 million [9] Much of this was based on the U.S. Banking industry where the Prime Info database was widely accepted.

At one time in the 1980s, PDGS was the world's largest integrated CAD system, spanning the US, Japan (Mazda was Ford's subsidiary/partner), (Cologne) Germany, (Dunton) England, and (Geelong) Australia.

The creators of PDGS, located in building #3 of Ford's Dearborn design headquarters, began working on the concept of parametrically driven geometry, which led to a PRIMEDesign system.

Prime embarked on a project headed by Vladimir Geisberg to build a CAD-CAM system of its own called PRIMEDesign.

During this period, in 1985, Sam Geisberg left Computervision to found Parametric Technology Corporation and produce a parameter driven CAD system called ProEngineer.

By the late eighties, the company was having problems retaining customers who were moving to lower-cost systems, as minicomputers entered their decline to obsolescence.

In 1988, financier Bennett S. LeBow attempted a hostile takeover of Prime, leveraging his much smaller MAI Basic Four company.

Various problems dogged this project, the holding company organized by Whitney went bankrupt, and the resulting severe financial distress made it much harder for Prime to deal with the accelerating downturn in its core business.

[19] After the computer design and manufacturing portions of the company were shut down, the only viable business that remained was the Computervision subsidiary, an early pioneer in CAD/CAM, which was acquired in a hostile takeover 1988.

[21] The company operating system, PRIMOS was originally written mostly in the Fortran IV programming language with some assembler.

[28] Prime acquired the OAS application from its developer, ACS America Inc., a now-defunct New York City software house.

This "intelligent workstation" concept for word processing was similar to the functions of popular systems from rival Wang Laboratories.

Prime's intelligent workstation for word processing was faster because it used RS232C cabling runs instead of the coaxial links that Wang's systems used.

Nonetheless, the word processing was not of the highest quality, and the PT65 was subject to software errors that scrambled the documents being worked on.

Prime Information allowed rapid 4GL or 4GL-like development of applications around relational or quasi-relational database structures.

In addition, the PRIMOS operating system would run unaltered across all Prime platforms; from the 2250 up to 750 (what would be considered today as a server).

As a result, the Data Collector (rooms) would contain several 750 class machines, each with rows of CDC 300 or 600 MB drives.

Prime gained expertise over the years with its collaboration with Ford and continued to expand into the CAD market with its Medusa product.

The software used on this computer system, PDN Mail, developed by Robert Ullmann, was designed to use the encoding header field that was later explained in a Request for Comments.

Before MIME existed, PDN Mail was able to perform the same functions and was used to send software updates as well as all sorts of attachments between systems.