In the early 1960s Ericsson hired the Swedish architecture and design company Ahlgren, Olsson & Silow (AOS) to develop Dialog, a new standard telephone that was to apply high end technology and reach international markets. Dialog attained great popularity and maintained its place within homes into the 1990s. This design classic has become an object of desire amongst collectors and telephone enthusiasts. New technology and the increased liberties in form resulted in the end of the era of number disc telephones. The 1972 version of the phone, equipped with buttons in place of the rotary dial, never became as popular as its predecessor.