In the early 1960s Philips tasked two different teams to design a high-quality tape cartridge for home use, utilizing thinner and narrower tape compared to what was used in reel-to-reel tape recorders. A team at its Vienna factory, which had experience with dictation machines, developed the Einloch-Kassette, or single-hole cassette with involvement from Grundig. At the same time, a team in Hasselt led by Lou Ottens developed a two-hole cassette under the name Pocket Recorder.
in the early 1960s philips tasked two different teams to design a high-quality tape cartridge for home use utilizing thinner and narrower tape compared to what was used in reel-to-reel tape recorders a team at its vienna factory which had experience with dictation machines developed the einloch-kassette or single-hole cassette with involvement from grundig at the same time a team in hasselt led by lou ottens developed a two-hole cassette under the name pocket recorder