Sansa e200 series Philips GoGear SA9200 PortalPlayer APX PortalPlayer's application processor series. Used by: Microsoft Zune HD The current generation NVIDIA Tegra mobile processors References External links PortalPlayer Wiki at Rockbox (Open Source firmware) mi4 file format of the firmware that almost all (non-iPod) Portalplayer models use Fabless semiconductor companies Companies based in Santa Clara, California IPod software Electronics companies established in 1999 Companies formerly listed on the Nasdaq Defunct semiconductor companies of the United States 2007 mergers and acquisitions Nvidia 1999 establishments in California