AT&T Information Systems (ATTIS) was the fully separate subsidiary of American Telephone & Telegraph Company (AT&T) which focused on computer technology ventures and telephone sales, and other unregulated business. It was one of the three core units of AT&T formed after the breakup of the Bell System.
AT&T Information Systems Wikipedia
In 1979 and 1980, the Federal Communications Commission (FCC) conducted Computer Inquiry I and II, which restricted Western Electric from selling "enhanced services", such as telephone equipment and other unregulated business, except through a fully separated AT&T subsidiary. As a result, American Bell, Inc. was formed, and began operations in 1982.
Employees at American Bell who worked in AT&T facilities that housed Bell Labs and Western Electric offices often encountered bureaucratic red tape, such as restrictions on using the one library in the same building because it was owned by Bell Labs.
American Bell contained two core units:American Bell Consumer Products - sold residential telephones/terminal equipment
American Bell Advanced Information Systems - sold business telephone/terminal equipment, such as the American Bell Merlin system
The AT&T Globe logo, originally designed by Saul Bass and sometimes informally called the "Death Star" for its visual similarity to the weapon of that name in the Star Wars movie franchise, originated for use with American Bell. When Judge Greene banned AT&T from using any Bell marks whatsoever after the breakup, except for usage of the Bell Labs name, AT&T switched over to the Globe logo.
Since AT&T was required to divest the Bell logo and trademark to the Baby Bells, American Bell was renamed AT&T Information Systems on January 1, 1984. The business unit, American Bell Advanced Information Systems, was absorbed into AT&T Network Systems, while American Bell Consumer Products, renamed AT&T Consumer Products, became a unit of AT&T Technologies.
AT&T Information Systems held its status as separate from any other AT&T company until 1986, following several FCC decisions which loosened restrictions set before the breakup. It was completely absorbed into American Telephone and Telegraph Company in 1989.