Compact_disc

Heitaro Nakajima, who developed an early digital audio recorder within Japan's national public broadcasting organization NHK in 1970, became general manager of Sony's audio department in 1971. His team developed a digital PCM adaptor audio tape recorder using a Betamax video recorder in 1973. After this, in 1974 the leap to storing digital audio on an optical disc was easily made. Sony first publicly demonstrated an optical digital audio disc in September 1976. A year later, in September 1977, Sony showed the press a 30 cm disc that could play 60 minutes of digital audio (44,100 Hz sampling rate and 16-bit resolution) using MFM modulation. In September 1978, the company demonstrated an optical digital audio disc with a 150-minute playing time, 44,056 Hz sampling rate, 16-bit linear resolution, and cross-interleaved error correction code—specifications similar to those later settled upon for the standard Compact Disc format in 1980. Technical details of Sony's digital audio disc were presented during the 62nd AES Convention, held on 13–16 March 1979, in Brussels. Sony's AES technical paper was published on 1 March 1979. A week later, on 8 March, Philips publicly demonstrated a prototype of an optical digital audio disc at a press conference called "Philips Introduce Compact Disc" in Eindhoven, Netherlands.

Question: what piece of technology is mentioned last?
Answer: Compact Disc

Question: What occurred in the 77th year of the 20th century?
Answer: Sony showed the press a 30 cm disc that could play 60 minutes of digital audio (44,100 Hz sampling rate and 16-bit resolution) using MFM modulation

Question: what period in time is mentioned second to last?
Answer: 1 March 1979

Question: Where did Nakajima work second, NHK or Sony?
Answer: Sony

Question: What occurred in the 78th year of the 20th century?
Answer: the company demonstrated an optical digital audio disc with a 150-minute playing time, 44,056 Hz sampling rate, 16-bit linear resolution, and cross-interleaved error correction code

Question: Which happened before 1971, Heitaro Nakajima developed an early digital audio recorder or his team developed a digital PCM adaptor audio tape recorder?
Answer: developed an early digital audio recorder

Question: Which happened first, Heitaro Nakajima developed an early digital audio recorder or became general manager of Sony's audio department?
Answer: developed an early digital audio recorder

Question: What occurred in the 74th year of the 20th century?
Answer: the leap to storing digital audio on an optical disc was easily made

Question: what time span is mentioned last?
Answer: A week

Question: what company is mentioned second to last?
Answer: Sony

Question: what period in time is mentioned last?
Answer: 8 March

Question: Which happened before 1975, Heitaro Nakajima became general manager of Sony's audio department or Sony first publicly demonstrated an optical digital audio disc?
Answer: became general manager of Sony's audio department

Question: Which happened sooner, Sony's AES technical paper was published or the 62nd AES Convention was held?
Answer: Sony's AES technical paper was published

Question: What occurred in the 71st year of the 20th century?
Answer: Heitaro Nakajima, who developed an early digital audio recorder within Japan's national public broadcasting organization NHK in 1970, became general manager of Sony's audio department