Before the iPod, there was the Diamond Rio PMP300.
Not that you'd remember.
Launched in 1998, the PMP300 became an instant hit, but then the hype faded faster than Milli Vanilli. One thing, though, was notable about the player. It carried the MAS3507 MP3 decoder chip—a RISC-based digital signal processor with an instruction set optimized for audio compression and decompression.
MAS3507 MP3 Decoder
Manufacturer: Micronas Semiconductor
Category: Amplifiers and Audio
The chip, developed by Micronas (now TDK-Micronas), let the Rio squeeze about a dozen songs into its flash memory. This is laughable by today's standards, but at the time it was just enough to compete with portable CD players, which suffered from a tendency to skip if jostled. The Rio and its successors paved the way for the iPod, and now you can carry thousands of songs—and all of Milli Vanilli's albums and music videos—in your pocket.
As this Micronas design document shows, the MAS3507 was built around doing only one thing well—decoding MPEG Audio Layer III data, a.k.a. MP3 files. Originally developed simply as the storage subsystem for holding the soundtrack of MPEG videos, the MP3 format took on a life of its own. Image: Micronas