S3 Inc has acquired Loveland, Colorado-based OneStep LLC, the software development firm that supplies the Rio Audio Manager software to Rioport.com Inc. Rioport is the subsidiary of Diamond Multimedia Inc responsible for MP3 internet audio business, and OneStep is used in conjunction with Diamond’s Rio MP3 players. S3 is in the process of acquiring Diamond.

Terms of the acquisition were not revealed. OneStep’s Audio Manager – which it introduced in June under the name Jukebox Xtreme – is designed to enable audio enthusiasts to acquire, create, organize and play back music or spoken audio programs through one PC application. It is comparable to RealNetworks Inc’s RealJukebox. RealNetworks introduced the beta 2 version of RealJukebox earlier this week, along with an expanded version, RealJukebox Plus. OneStep’s version of the product supports Creative Lab’s Inc’s Nomad player as well as the Rio.

S3 said that OneStep’s Audio Manager was one of the key technologies behind Rioport’s agreements with MTV Networks Online and Compaq Computer Corp. Last month, Diamond won an OEM deal with Compaq, under which the PC maker will offer consumers buying its Presario 5000 Series entertainment PCs a special version of the 32Mb Rio PMP300 Player along with a full version of RioPort Audio Manager software. And MTV Networks Online signed a deal with RioPort for the distribution and sale of digital music across its MTV.com, VH1.com, Nick.com, and SonicNet web sites, and also from its forthcoming Buggles Project music networking site. RioPort will create branded players for each of the MTV sites, and MTV will have access to RioPort’s catalog of SDMI security compliant licensed music. Diamond has a similar deal with Universal Music Group.

OneStep’s primary product, introduced at the end of last year, is the personal organizer software OneStep Connect, for PCs used in conjunction with 3Com Corp’s PalmPilot. OneStep Connect provides access to fax, email, browsers, phone dialers, and Microsoft Word templates for letters, envelopes and memos. The company was founded in 1996.