www/main.t

#define _LOGO_ <img src="rockbox400.png" width=400 height=123>
#define _PAGE_ Open Source Jukebox Firmware
#include "head.t"

<p><small><a href="notes.html">research notes</a> &middot;
<a href="docs/">data sheets</a> &middot;
<a href="schematics/">schematics</a> &middot;
<a href="mods/">hardware mods</a> &middot;
<a href="http://bjorn.haxx.se/rockbox/mail.cgi">mail list archive</a> &middot;
<a href="tools.html">tools</a> &middot;
<a href="internals/">archos internals</a> &middot;
<a href="http://sourceforge.net/projects/rockbox/">sourceforge project</a>
</small>

<h2>Purpose</h2>

<p>The purpose of this project is to write an Open Source replacement
firmware for the Archos Jukebox <i>6000</i>, <i>Studio</i> and <i>Recorder</i> MP3 players.

<p>The main emphasis and first target is the Jukebox 6000.

#if 0
<h2>Warning</h2>
<p>All firmware mods on this page are still <i><b>highly experimental</b></i>.
Try them on your own risk. If you are not 100% sure of what you are doing, keep cool.
#endif

<h2>Activity</h2>

#include "activity.html"

<h2>News</h2>

<p><i>2002-03-25</i>: New section for
<a href="mods/">hardware modifications</a>.
First out is the long awaited
<a href="mods/serialport.html">serial port mod</a>.

<p><i>2002-03-25</i>: New instructions for
<a href="cross-gcc.html">how to build an SH-1 cross-compiler</a>.

<p><i>2002-03-14</i>: New linux patch and instructions for 
<a href="lock.html">unlocking the archos harddisk</a> if you have the "Part. Error" problem.

<p><i>2002-03-08</i>: Uploaded a simple example, showing
<a href="example/">how to build a program for the Archos</a>.

<p><i>2002-03-05</i>: The 
<a href="lock.html">harddisk password lock problem is solved</a>!
Development can now resume at full speed!

<p><i>2002-01-29</i>: If you have feature requests or suggestions,
please submit them to our
<a href="http://sourceforge.net/projects/rockbox/">Sourceforge page</a>.

<p><i>2002-01-19</i>: Cool logo submitted by Thomas Saeys.

<p><i>2002-01-16</i>: The project now has a proper name: Rockbox. 
Logos are welcome! :-)
<br>Also, Felix Arends wrote a quick <a href="sh-win/">tutorial</a>
for how to get sh-gcc running under windows.

<p><i>2002-01-09</i>: Nicolas Sauzede 
<a href="mail/rockbox-archive-2002-01/0096.shtml">found out</a>
how to 
<a href="mail/rockbox-archive-2002-01/0099.shtml">display icons and custom characters</a> on the Jukebox LCD.

<p><i>2002-01-08</i>: The two LCD charsets have been 
<a href="notes.html#charsets">mapped and drawn</a>.

<p><i>2002-01-07</i>:
<a href="mail/rockbox-archive-2002-01/0026.shtml">Jukebox LCD code</a>.
I have written a small test program that scrolls some text on the display.
You need
<a href="mail/rockbox-archive-2002-01/att-0026/01-archos.mod.gz">this file</a>
for units with ROM earlier than 4.50 and
<a href="mail/rockbox-archive-2002-01/att-0050/02-archos.mod.gz">this file</a>
for all others. (The files are gzipped, you need to unzip them before they will work.)

<p><i>2001-12-29</i>: Recorder LCD code. Gary Czvitkovicz knew the Recorder LCD controller since before and wrote some
<a href="mail/rockbox-archive-2001-12/att-0145/01-ajbr_lcd.zip">code</a>
that writes text on the Recorder screen.

<p><i>2001-12-13</i>: First program 
<a href="mail/rockbox-archive-2001-12/0070.shtml">released</a>!
A 550 bytes long 
<a href="mail/rockbox-archive-2001-12/att-0070/01-archos.mod">archos.mod</a>
that performs the amazing magic of flashing the red LED. :-)

<p><i>2001-12-11</i>: Checksum algorithm solved, thanks to Andy Choi. A new "scramble" utility is available.

<p><i>2001-12-09</i>: Working my way through the setup code. The <a href="notes.html">notes</a> are being updated continously.

<p><i>2001-12-08</i>: Analyzed the exception vector table. See <a href="notes.html">the notes</a>. Also, a <a href="mail.cgi">mailing list archive</a> is up.

<p><i>2001-12-07</i>:
 I just wrote this web page to announce descramble.c. 
I've disassembled one firmware version and looked a bit on the code, but no real analysis yet.
Summary: Lots of dreams, very little reality. :-)

<p>I've set up a mailing list: rockbox@cool.haxx.se.
To subscribe, send a message to <a href="mailto:majordomo@cool.haxx.se">majordomo@cool.haxx.se</a> with the words "subscribe rockbox" in the body.


<h2>About the hardware</h2>

<p>I wrote a <a href="/isd200/archos.html">"dissection" page</a> some months ago,
showing the inside of the Archos and listing the main components.
I have also collected a couple of <a href="docs/">data sheets</a>.

<h2>About the software</h2>

<p>The player has one version of the firmware burnt into flash ROM.
The first thing this version does after boot is to look for a file called
"archos.mod" in the root directory of the harddisk. 
If it exists, it is loaded into RAM and started.
This is how firmware upgrades are loaded.

<h3>File format</h3>
<p>The archos.mod file is scrambled, but luckily not using encryption.

<p>Each data byte is inverted and ROLed 1 bit.
The data is then spread over four memory segments. The two least significant bits of the address is used as segment number and the rest as offset in the segment. So, basically:

<ul>
<li>segment number = address % 4
<li>segment offset = address / 4
<li>segment length = imgsize / 4
</ul>

<p>A 6-byte header is added to the beginning of the scrambled image:
<ul>
<li>32 bit length (big-endian)
<li>16 bit checksum
</ul>

<h2>Dreams</h2>
<p>Ok, forget about reality, what could we do with this?

<ul>
<li>All those simple mp3-play features we sometimes miss:
 <ul>
 <li>No pause between songs
 <li>Mid-song resume
 <li>Mid-playlist resume
 <li>No-scan playlists
 <li>Unlimited playlist size
 <li>Autobuild playlists (such as "all songs in this directory tree")
 <li>Auto-continue play in the next directory
 <li>Current folder and all sub-folder random play
 <li>Full disk random play
 <li>REAL random (if press back it goes to the previous song that was played)
 <li>Multi song queue (folder queue)
</ul>
<li>Faster scroll speed
<li>Archos Recorder support. Most of the hardware is the same, but the display and some other things differ.
<li>All kinds of cool features done from the wire remote control, including controlling your Archos from your car radio (req hw mod)
<li>Ogg Vorbis support [unverified: the MAS is somewhat programmable, but enough?]
<li>Support for megabass switch (req hw mod) [unverified: I just saw the DAC docs shows how to do it switchable. we need a free port pin to be able to switch]
<li>Player control via USB [unverified]
<li>Memory expansion? [doubtful: the current DRAM chip only has 10 address lines. we'd have to pull off one heck of a hw mod to expand that]
</ul>

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