Discman was Sony's brand name for portable CD players. The first Discman, the Sony D-50 or D-5 (depending on region), was launched in 1984. The brand name changed to CD Walkman, initially for Japanese lineups launched between October 1997 and March 1998, and then entirely in 2000. Discman and CD Walkman players are no longer produced. Background Prior to the development of the Compact Disc, cassette tapes were the dominant form of audio storage in the then-fledgling portable audio industry. In 1979 Sony introduced the Walkman in Japan. When Sony realized the potential of the CD, the Walkman was promoted to mainstream buyers. Original development Sony improved the design of the CDP-101 CD player which was launched in 1982, reducing the power consumption and the number of parts needed and making it smaller. The cost was reduced to between 50,000 and 60,000 yen, in what was called the "CD CD Project", which stood for 'Compact Disc Cost Down' Project. By August 1983 the company was able to produce a CD player which was one-tenth the size of the original, and a portable CD player became a possibility. The aim was to create a player that was the same size as four CD cases stacked on top of each other. A piece of wood 13.4 cm across and about 4 cm thick was shown to the staff to illustrate the dimensions. The final design did not incorporate a power source and had a 9-volt (positive outer) coaxial jack on the rear. This allowed the use of an EBP-9LC wall adapter, a carrying sleeve which held six primary C cells, or rechargeable cells which could be charged in situ. The AC-D50 AC adapter was also available, which attached to the rear of the D-50/D-5 and allowed it to be powered from AC input at 110, 120, 220, or 240 V, 50 or 60 Hz, 9 W with a DC output of up to 500 mA. The AC-D50 also offered line level audio out, presented as two RCA jacks. Release The D-50/D-5 was launched in November 1984, two years after mass production of CDs began. The unit offered the same functions as the full-size CDP-101 player, but came without a remote control and the repeat function of the full-size unit. The D-50/D-5 retailed for 49,800 yen (US$350 in 1984), approximately half the price of the CDP-101. The D-50/D-5 sparked public interest in CDs,