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Wiki > Main > RioKarmaPort

Rockbox port to the Rio Karma

About the Rio Karma

The Rio Karma was a DAP with hard drive designed by Rio for Diamond Multimedia. It was aimed at a higher market than most other DAPs, primarily the audiophile and power user areas. To this day, few (if any) DAPs have ever matched it in terms of features. It has the ability to play mp3/wma/flac/wav/ogg file directly with it's original firmware.

Current Status

This port is still in a state of research. Most of the internal hardware is in use by other supported targets, but there are still some pieces I need information on.

There's a thread on the forums discussing the Karma here:

I'll continue the work as long as i have time(Alson Black posted.)And i really hope Karma owners could join to keep these works going on.

Hardware Summary

Here's what's known about the Karma's hardware thus far:

  • PortalPlayer 5003 SoC A-L; dual core ARM7, up to 90Mhz per core
  • Wolfson 8721/8731 DAC/headphone amp (same as the early iPods)
  • VDS VG T161251 1WFEBA 038022807
    display,custom. 160x128x2 bpp output (although the Original Firmware simulated grayscale by rapidly switching the pixels)
  • Cypress EZ-USB FX2 USB controller; chip number is CY7C68013-56PVC (you can see it in the image below on the lower left) (More info)
  • Intel 32Mbit Flash Memory(FWH,Firmware Hub); chip number is F320C3BD
  • Charger IC: Linear Tech LT1733 ISTR
  • The DAC is fed with a standard I2S signal. Pin 2 is the I2S bit clock, Pin 3 is I2S data, and Pin 4 is I2S left/right clock.
  • Hard drive is a Hitachi Travelstar Model HTC424020F7AT00 drive. (4200 RPM; 44-pin IDE connector) (NOTE: The iriver H10 and Dell DJ also use this same hard drive!)
  • The battery is rated at 1600mAh; it is actually 2 x 800mAh cells, with a protection circuit on the top (it's the little bulge where the wires come out)
  • The national semiconductor 83847A5,Ethernet PHY chip.No VS27AM.(datasheet see below.) (More info)) (All packing(search for 83847)) (Reference Designs, Models, Drivers, and Eval Boards)

Filesystem and Transfer Protocol

According to krazykit on IRC, the Karma used a custom transfer protocol that is neither MSC nor MTP. We'll need to research this further. (Note: This may need a fully working USB stack in Rockbox first!)

Also pointed out was the fact that the Karma used a custom filesystem called OMFS, but the Linux-Karma project has drivers for Linux available so one can access the filesystem. (See link below!)

OMFS is not a journaled filesystem, and does not offer any better behavior than a FAT32 filesystem. For the Karma, we may need to either write a tool to format the drive to FAT32 before installing the firmware, or advise users to format the Karma beforehand. RBUtil could include the option to format the drive before installing.

Of special note is the Karma's dock: the dock has an Ethernet port built in, so file transfers may also be handled via a standard network connection and the Java-based Rio Music Manager Lite.


(provided by forum user space_ghost)


Karma Firmware

The Rio Karma's firmware is based on eCos, an open source operating system for embedded systems. The OS itself is licensed under the RHEPL v1.1 (Red Hat eCos Public License; basically the GPL with exceptions); a link to the license is here.

According to details from an article on (link below), it IS possible to build your own firmware for the Karma. The Karma firmware was built with GCC; configuration is slightly tricky but possible.

As stated above, the filesystem and non-standard transfer protocol need to be addressed.

Firmware Updating

The Karma is not mi4 based as previously thought.

The firmware is stored in flash, although a few portions are stored on the hard disk, such as RMML. This makes it possible to always restore the player even with a blank hard disk.

Recommended Sources of Information

Points of interest revealed by evilnick and krazykit:

Riovolution forums (the old link is gone, and the main page now redirects to the old forums)
Unofficial empeg BBS
New Riovolution forums (Use this if the page above doesn't work for you)


Wikipedia's entry on the Rio Karma
1000 Geeky Details about the Rio Karma (from
Linux-Karma project
Karma Disassembly Instructions
eCos Homepage

I Attachment Action Size Date Who Comment
CY7C68013-56PVC-Datasheet.pdfpdf CY7C68013-56PVC-Datasheet.pdf manage 1880.7 K 30 Jan 2008 - 15:05 RobertMenes Datasheet for Cypress EZ-USB FX2 USB Controller
DP83847.pdfpdf DP83847.pdf manage 378.1 K 26 Jul 2008 - 19:26 AlsonBlack Datasheet of PHY VS27AM,838475.
karma-lsusb-info.txttxt karma-lsusb-info.txt manage 1.9 K 01 Feb 2008 - 00:46 RobertMenes Results of lsusb -v with the Rio Karma
r20 - 02 Apr 2021 - 20:46:07 - UnknownUser

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