Portable Audio Player Requirements

Brief Summary. Samsung seems to have very good longevity for hardware (they do make lots of cell phones, too). Samsunk decided to get in bed with Micro$oft and remove vorbis support and thumb drive capabilities with new firmware and have earned the wrath of many (isn't that grounds for a law suit based on false advertisement of capabilities?). Creative Labs seems to have good hardware quality but severly lacks features in their lower end models (basically paying a lot for their brand name). The Creative Labs video capable unit seems good for the price. SanDisk has very good features in the lower models but seems to lack hardware quality intermittently (RockBox unofficial firmware supports SD-HC in their expandable models). Kanguru seems to have good features in the lower end models but unknown hardware quality. Mach Speed seems to have generally low hardware quality (Trio seems to be a medium level). Coby seems to have poor hardware quality (MP- C895 may be ok, though). Sony seems to want to play their own bastardized DRM games that give people too many problems. Apple essentially does the same thing with the iPod but at least has a far better interface for it that usually works (also absurdly high costs for their brand name). Philips and RCA should know better. Other brands are unknown and probably bad hardware. Considering these things aren't overly new and have established hardware (none of this is rocket science), physical unit and OS problems shouldn't happen but still seem rampant.

Here is the list of features that generally makes up a good and flexible unit. One would think that marketing people and focus groups would have come up with this a long time ago, but... nevermind.

Sansa c250 dump...

sdmx7-2048 (generic model number, may be anything)
sdmx7-2048-a18 (US region)
sdmx7-2048-c18 (Canada region)
sdmx7-2048-e70 (UK region, v1 reported)
sdmx7-2048-p70 (India region)
sdmx7-2048-q18 (Australia region)

I ignored the warning in the version.sdk file and edited the two lines
FW: 01.00.04E
Region: Europe
FW: 01.00.03A
Region: America
(The file version.txt had no warnig in it, so I simply deleted it)
The Sansa Updater still showed FW 1.00.04 when I clicked on 'Check for updates now'.
I disconnected the c250 fom my computer, waited for the 'refresh database' to finish and reconnected it.
The Sansa Updater now showed FW 1.00.03 and I could download and install the firmware.

if it finds a update, let it download it, but when it says to unplug the
player to complete the install, don't. just exit the updater, go to the
player's root directory where all the MUSIC and PHOTO etc. folders are,
and there are 2 new files there: FIRMWARE.MI4 and PRIBOOTLOADER.ROM .so,
all you have to do is to copy-paste these 2 files somewhere in your
computer, pack them, upload somehere(ie. rapidshare) and voila! there we
have it! hmmm..., now we just need that guy... ;D


Screen display resolution: 132x80

Dual Rockbox Boot Nerve Pinch: Hold Left button while pressing power
button to get back to original OS.

UMS neck pinch override: unit=on, hold=on, hold down the rewind button and
plug in the player until it says "connected".

Charge under Rockbox neck pinch: hold down Select and plug it in.

Recover neck pinch: unit=off, hold=on, hold down the record button and
plug in the player until it says "new hardware is ready for use". A new
16meg drive will show up on the computer. ?copy in raw firmware files? A
blank text file called "sansa.fmt" will cause it to format the drive and
reinstall the firmware. (NEVER format a disk in recovery mode (it will
brick beyond brick), use UMS instead).

Diagnosis neck pinch: unit=off, hold=on, hold down the submenu button and
plug in the USB cable. e200tool can be used to unbrick a c200 if it can
get into diag mode.

jdarr: m250, express (microSD)

easytag can be used with the DOS option to create playlists.?


reformat fat32 (probably should do all this without any unplugs/resets):
back up all the file.
fdisk /dev/sdb #change partition type to 'c' and bootable.
mkfs.vfat -c -F 32 -n "Sansa c250" /dev/sdb1
restore all the files.

long play = stop music.
long select = go to file browser.

Left/Right/Play/Submenu: Move about the virtual keyboard (moves the solid
Select: Inserts the selected keyboard letter at the current cursor
Rec+Left or Rec+Right: Move the line cursor within the text line.
Rec+Submenu: Deletes the character before the line cursor.
Volume Up/Volume Down: Exits the virtual keyboard and saves any changes.
Power: Exits the virtual keyboard without saving any changes.

my review: c250 (v1 01.01.05P)

- Hardware needs capacitor blocker for DC offset.

- Recorder is 5kHz frequency tops (even if recorded at 22kHz). Everything
else above is a mirrored harmonic distortion (freq cut it if long term
archiving). Frequency roll off is a little below 4kHz (telephone quality).
Low freq rolloff is about 40Hz. (native Sansa records 16kHz/16bit/mono.)

. Sansa tells me "what I can't do", Rockbox tells me "what I can do".

. Sansa (and other programmers in general) = morons. Rockbox way out does
anything available.

. For those morons who keep complaining about corruption and
instabilities, learn how to unmount a USB device before just yanking it
out of the slot. (Hint: it's a tiny little icon in the task bar.)

- Some corporate idiot partitioned and formatted the drive FAT16 (0x6 from
fdisk) instead of FAT32 (0xC from fdisk; kernel module does show up as
vfat, but that's a universal driver). That has incredibly high overhead
for any disk over a couple hundred megabytes and will end up wasting an
absurd amount of space that could have been used for songs. It is also
technically limited to 8.3 file names.

. In UMS/MSC mode, linux fdisk reports the hidden partition (0x84, tracks
1002-1012) of about 20megs at the end of the internal flash disk.
Unfortunately it also gives the obnoxious "physical/logical beginnings"
warnings. This doesn't affect the mounting of the main partition. The
hidden partition doesn't have a recognized file system type when trying to

+ In UMS/MSC mode, linux can both image and file backup the unit in case
something gets corrupted.

- Screen color quality is poor. Color theme chosen by SanDisk was poor and
hard to see (need to tilt the unit sometimes).

- No menu setting to turn down bright blue LED on keypad.

. The media converter program is just that and doesn't have any real
settings control over the unit. If your IQ is higher than room
temperature, you can do conversions yourself with higher quality programs.

- The USB settings menu doesn't exist in this firmware version.

Under linux, one must use the neck-pinch method to manually get the unit
in UMS mode. (If the slow auto detect mode is used, data will be there but
not recognized.) When the partition is unmounted then USB cable pulled,
the unit will do a "Refresh Database" and find the new music and photos in
the associated dirs.

Music and pictures copied in with UMS mode (and that do show up on the
unit's menu system) do not show up in MTP disk emulation mode.

MTP mode shows up different under windoze XP (MTP funky emulated disk
mode). This mode does not show up as a standard drive letter.

Cannot fully copy/paste out music/pics under windoze (end up with partial
files, stuck to MTP disk emulation mode). Tried 2 different USB slots.

Sansa web Flash page is next to useless, obnoxious, and slow on flash
blocked browsers.

Sansa firmware updater icon in the windoze task bar never stops moving

Media Converter online update automatically fails.

When USB connected, no way to turn off back light nor their annoying
animation. Holding down the power button for 30s will force shut down the
entire unit, including the battery charger.

+ High volume mode allows my real headphones to adequately play.

+ Will show JPEG images of varying sizes and auto-scale them to the tiny
display. Those images can be split into a subdirectory.

+ PHOTO. Deeper sub directories are supported but only directories with
pictures in them will show up in the list as a group (which is
convenient). The list is also flat and does not navigate down into
subdir's like one would do in a normal file system (which can be annoying
if directories aren't very well named).

- PHOTO. There is no zoom in function (like my cell phone has).

- Sansa depends on ID3 tag in the MP3 or it will just use the file name
and "unknown" in the music list. While music can be directory grouped, it
will not show up as such in the song list. If the ID3's aren't perfect,
navigation and grouping will get confusing. However the groupings end up
is how they will be played. The unit will not play beyond a grouping if it
is used that way.

+ In a music directory, songs seem to be played by alphabetical file order
and not by the order they were copied in.

+ As a semi-undocumented feature, pressing the Menu/Power button will take
you to the main menu, but pressing it again will take you back to where
you were previously.

. The FM antenna is actually the headphone's cable. If you get a longer
cable and hold it horizontally instead of vertically, reception is far
better. This should be true for just about all radios of this type.

+ If unit is turned off in the middle of a track, it will turn back on
paused at the last position (good for audio book and podcast people).

+ Removable and replacable rechargable battery. I would have preferred the
higher capacity and ubiquity of a pair of AA/AAA's, though.

- Battery cover instructions seem simple enough, but the cover also seems
to be fused to the unit.

- The rubber cord lanyard works but keeps its folding kinks that make it
obnoxious. Regular nylon string would have been a better choice.

- USB cable is a custom ended cable and probably very expensive to replace
if something happened or a spare was needed. It would have been nice if
this thing has mini-USB or a built in connector (especially since it has
the micro-SD slot in it for extended data storage, special cables as big
as the device itself are clumsy).

- Rockbox: only supports the v1 hardware right now (thankfully what I was
shipped and will hopefully keep if I have to RMA).

+ Rockbox: adds ogg/vorbis, FLAC, m4a, and support for many others.

+ Rockbox: multiple playlist type support (including directory based).
Play lists can be re-randomized.

+ Rockbox: Playing based on file structure (directories and sub directory
option) or by database (ID3 tags).

+ Rockbox: users can rename files and directories. Users can also move

+ Rockbox: theme support and multiple font support (larger font for car

+ Rockbox: can set multiple recording levels and default directory. A peak
meter, clip flasher, and gain settings are also included. Record files can
be auto-split and a prerecord buffer is also included.

+ Rockbox: fine tuned pitch control in playback.

+ Rockbox: 64 presets instead of the Sansa 20. Can also name presets.
There are premade preset files for many major cities.

+ Rockbox: photo viewer has zoom and pan functions.

+ Rockbox: Themes. None of those lousy Sansa blue on white hard to see
colors. Theme settings can be manually changed. Themes can also be saved
for settings (rapid change from car, headphones, and home stereo mode).

+ Rockbox: Plugins. Games (Doom, chess, blackjack, solitare, others),
demos (waveform viewers, Matrix screen saver, fractals), and utilities
(scientific calculator, text editor, battery, clock, metronome).

+ Rockbox: text viewer plugin for reading manuals or books. It has real
word wrap and paging.

+ Rockbox: mpeg1 and mpeg2 video playback.

? Frequency sweeps. channel phasing?
? install knoppix
? find carrying case.


Damn Small Linux install.

fat32 requires syslinux 3.35+ (only older in debian/etch)
auto-apt run make
mkdir ../out
cp unix/syslinux memdisk/memdisk mbr/mbr.bin mkdiskimage isolinux.bin \
 ldlinux.* extlinux.* extlinux/extlinux ../out/

In the copy of the /boot directory, replace the various syslinux files
with the newly compiled ones.

* Mount USB drive, with e.g. mount /dev/sdx1 /flash - can be either FAT16
or FAT32!
* Mount ISO image, with e.g. mount /tmp/dsl-3.2.iso /tmp/iso -o loop
* Copy all contents from ISO to USB drive: cp -vr /tmp/iso/* /flash/
* Rename and move syslinux files to root directory: mv
/flash/boot/isolinux/* /flash/
* Rename isolinux.cfg: mv /flash/isolinux.cfg /flash/syslinux.cfg
-> edit syslinux.cfg if needed (memtest and boot floppies).
* Unmount USB drive: umount /flash
* Install syslinux: syslinux /dev/sdx1 and eventually set the MBR boot
flag for this partition (with fdisk).

cd /mnt/flash/boot/grub
cp /boot/grub/*stage* . #copy in main OS grub files
edit the menu.lst file accordingly.
go into grub:
 cat (hd2,0)/z #to see if that's the real partition
 root (hd2,0) #verify listed partition type
 setup (hd2)
from RAID method:
 device (hd0) /dev/sdb
 cat (hd0,0)/z #to see if that's the real partition
 root (hd0,0) #verify listed partition type
 setup (hd0)


right click desktop, select backup/restore, select device.
Restore cheat code: restore=sda1
backup list: /opt/.filetool.lst
exclude list: /opt/.xfiletool.lst

Add to include:


scope test:
dc offset issues.
constant voltage out (about 0.6v peak) from 5-20kHz.
above 20kHz, waveform barfs.
noticable jitter problems.
noticable ringing on the square wave.
full volume doesn't seem to clip.