WHEN the Sony Walkman went on sale 30 years ago, it was shown off by a skateboarder to illustrate how the portable cassette-tape player delivered music on-the-go — a totally innovative idea back in 1979. Today, Sony Corp. is struggling to reinvent itself and win back its reputation as a pioneer of razzle-dazzle gadgetry once exemplified in the Walkman, which Wednesday had its 30th anniversary marked with a special display at Sony's corporate archives. The manufacturer, which also makes Vaio personal computers and Cyber-shot cameras, hasn't had a decisive hit like the Walkman for years, and has taken a battering in the portable music player market to Apple Inc.'s iPod. Sony has sold 385 million Walkman machines worldwide in 30 years as it evolved from playing cassettes to compact disks then minidisks — a smaller version of the CD — and finally digital files. Apple has sold more than 210 million iPod machines worldwide in eight years. There is even some speculation in the Japanese media that Sony should drop the Walkman brand — a name associated with Sony's rise from its humble beginnings in 1946 with just 20 employees to one of the first Japanese companies to successfully go global. “The Walkman's gap with the iPod has grown so definitive, it would be extremely difficult for Sony to catch up, even if it were to start from scratch to try to boost market share,” said Kazuharu Miura, analyst with Daiwa Institute of Research in Tokyo. Miura believes Sony can hope to be unique with its PlayStation 3 and PlayStation Portable video game consoles, but it has yet to offer outstanding electronics products that exploit such strengths. When the iPod began selling like hotcakes several years ago, a Japanese reporter asked Shizuo Takashino, one of the developers of the original Walkman, why Sony hadn't come up with the idea. Afterall, the iPod seemed like something that should have been a trademark Sony product. One major reason for the iPod's massive popularity was that it played MP3 files, which are widely used for online music and compatible with many devices. In a special display at Tokyo's Sony Archive building, opening Wednesday to commemorate the Walkman's 30-year history, an impassioned Akio Morita, Sony's co-founder, speaks to employees in a 1989 video to celebrate the 10th anniversary of the Walkman. “We can deliver a totally new kind of thrill to people with the Walkman,” said the silver-haired Morita, proudly wearing a gray factory-worker jacket and surrounding himself with dozens of colorful Walkman machines. “We must make more and more products like the Walkman.” The original Walkman was as big as a paperback book, and weighed 390 grams (14 ounces). It wasn't cheap, especially for those days, costing 33,000 yen ($340). But people snatched it up. The Walkman exhibit, which runs through Dec. 25, shows models that are still on sale, some about the size of a lighter that play digital music files.