اختراعات – علاء العبادي Page 2
1948 – Columbia Records introduces the longplaying (LP) record, which is played at revolutions per minute (RPM). 1949 – RCA introduces 45 RPM records. 1965 – 8track magnetic tape introduced. 1969 – Internet created. 1979 – Sony Walkman cassette player introduced (By 1995, 150 million sold)