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archosfaq

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ArchosFAQ - Frequently Asked Questions regarding Rockbox for the Archos line of players

What Archos players does Rockbox run on?

Rockbox runs on the Archos Player, Recorder, FM Recorder, Ondio FM and Ondio SP. More information on supported players is available on the DeviceChart page.

Will Rockbox work on any of Archos' other units?

Other than the currently supported models: no, probably not (see GminiPort for the Archos Gmini porting effort). If Archos releases another rockbox-able player (such as the V2) then rockbox will find its way onto it, but their new devices as the MM and AV units are completely different hardware and probably won't be supported by Rockbox unless someone enthusiastically reverse engineers them and submits patches to make it happen.

Can the changes or the software that Rockbox suggests or offers possibly damage my mp3 player?

All firmware mods that are presented are still highly experimental. Use them at your own risk. We offer no guarantees that this software, or the hardware modifications we show, will not damage your player or void your warranty. That said, we have not been able to damage any of our units by modifying only the firmware. You can accidentally password protect your hard disk, but there are ways around that. (See below.)

Note: Archos claims installing Rockbox voids their warranty.

Will Rockbox ever support OGG or other codecs on the Archos?

Pessimist's Answer: At the current time we believe this is not very likely. The Micronas chip (MAS3507) decoder in the Archos does not natively support decoding and there is very little program space in the player to implement it ourselves. The alternative would be to write a software decoder as part of the Rockbox firmware. However, as much as we love our players, the computing power of the Archos (SH1 microcontroller) is not fully sufficient for this need.

Optimist's Answer: We can play any format if only we can write code for the DSP to decode it. The MAS 3507 (and 3587) are generic DSPs that simply have MP3 codecs in ROM. We can download new codecs in them and we will be the first to celebrate if we can get OGG or FLAC or anything into these DSPs. Unfortunately, we have no docs or tools for writing new MAS DSP code and Micronas is very secretive about it. If anyone can help, please get in touch!

The recent release of Tremor (integer Ogg decoder) indicates it uses around 100 KB for lookup tables. That's not unreasonable for a decoder, but we only have 4 KB for both code and data. So the grim reality is that Ogg will never be supported by the Archos Players and Recorders.

What about supporting playing of WMA files?

Dear Mr. Gates, you have two options. Re-read previous question, or go buy your own project.

But you don't understand, I'm not talking about decoding here, since the data we want may already be in the decoded format (PCM).

Okay, last time. No. At least not for the Archos line of players. We have no problems whatsoever reading different file formats, call it PCM, WAV, GRI, PQR or whatever. The problem is that the CODEC on the Archos players only accepts MP3 data and nothing else. We could write a new CODEC if we knew how to do it, but there is no documentation on the DSP. Please note that we have no access to the DAC, so we can't send the data directly to the DAC.

What is the most recent version of Rockbox for Archos?

The Release version (currently 2.4) for the Archos line is a frozen known-good state. This means that we are confident that few, if any, significant bugs reside within the code for that version. This is the version for the common user. Head on over to http://www.rockbox.org/download/ and pull it down. Make sure to read the release notes. (http://www.rockbox.org/download/rockbox-2.4-notes.txt). We anticipate that version 2.5 will be released in the relatively near future.

What do you plan to add to coming versions?

We don't plan versions in detail. We just write code, and when it feels right we release a new version.

I tried one of your firmware files and now I can't access my hard disk! When I turn on my jukebox, it says: Part. Error Pls Chck HD

Your hard disk has been password protected. We're not 100% sure why it happens, but you can unlock it yourself. Look at: http://www.rockbox.org/lock.html

Note: This is a very rare problem. Most people who think they have a locked disk actually just experience hardware and/or driver problems.

I've heard talk of a 'Rolo'. What is that? (Or 'All you ever wanted to know about Rockbox boot loaders')

Rolo is our bootloader. Rolo became available with our 1.4 release. To make use of Rolo, you must have a file with the same extension as your Rockbox firmware (.ajz on Recorder, .mod on Player) but a different name. You can then browse to it, and you 'run' the other firmware you wish to switch to by pressing play. Remember to set the Show Files option to "Supported" or "All" to be able to see the firmware files in the browser.

*Poof* You will reboot to that firmware. (Note that in order to return to Rockbox you may need to reboot manually if the new firmware you loaded does not have a bootloader itself.)

Can I use the Archos as an USB hard disk to store data from my PDA/ digital camera/phone etc.

No. See NoDo#4_Interfacing_with_other_USB_dev

When I use Rockbox my Archos jukebox's red "error" light turns on a lot, but this doesn't happen on the factory firmware. Why?

Rockbox uses the red LED as harddisk activity light, not as an error light. Relax and enjoy the music.

Does Rockbox for Archos support other fonts/character sets?

Recorders do, Players don't.

How do I use the loadable fonts?

If you own a Recorder see: http://www.rockbox.org/fonts/ Players cannot make use of loadable fonts.

Why can't I use loadable fonts on the Player?

This is because the Player font is character cell based (as opposed to the Recorder's bitmap based display). This means that we are able to choose what characters to display, but not how to display them. We do have the ability to change/create up to 4 chars on one model and 8 on another, however we are currently using several of these 'letters' to store icons for the player.

Why don't you have as many games available for the Players?

The display on the Players is character cell and not bitmap based. This means there is much more limitations in the amount of graphics that can be displayed, and thus what kind of games can be written.

I keep shutting off my player in my pocket. Can the OFF (Recorder) or STOP (Player) key be locked?

No. Unfortunately, the ON/OFF mechanisms are handled entirely in hardware. The firmware can read the keys, but can't prevent them from shutting off the player.

Now that I can record, can I use custom codecs (like LAME)?

The MP3 encoder for the Archos players is in the MAS3587F chip, and nothing we can change.

What are the max/min bitrates for recording on the Archos Recorder's encoder?

The builtin encoder is variable bit rate only with a max of 192kbit/s, and a min of 32kbit/s.

Would it be possible to record from line in on the Archos player?

No.

I installed Rockbox on my Archos, removed the jukebox safely and rebooted, but Rockbox still didn't load. What is wrong? I am running Windows.

The old MOD/AJZ was not entirely deleted from the disk. It is still there, and the boot loader finds that one instead of the new file. Here's what you can do:

Download and install Directory Snoop (version 4.03 in November 2002) from http://www.briggsoft.com/dsnoop.htm. Directory Snoop can display true drive contents by bypassing the operating system and reading the raw drive sectors directly. It's shareware, the trial version can be used 25 times.

Plug the Jukebox in the PC as usual and power on

Launch Directory snoop

Click on the Jukebox drive letter in the [select drive] field in the toolbar. The content of the jukebox hard drive appears in the main window. Files which appear in red color don't seem to be present on the hard drive, but they still here.

Simply select the appropriate files (red color) and purge them (Purge button). Of course, don't erase the new archos.mod file and the .rockbox directory :)

Safely remove (Windows unmount device function) the Jukebox. Power it up and ...voila... Rockbox is there!

(Thanks to Olivier Rafidison for this info)

Another alternative:

Copy the firmware file to the jukebox again. Windows will rename it to "Copy of XXXXX"

Delete the original firmware file and remove the "Copy of" part from the new file name

Reboot

If it doesn't load the correct firmware, do the whle procedure again until the new file is recognized.

What kind of mic can I connect to my AJBR?

There are several types of microphones.

Dynamic: The one that's available from Archos is a dynamic one. Dynamic microphones do not need external power to operate. They do however need a preamplifier to use them on your AJBR, which is included with the Archos stereo microphone.

cheap
no good sound quality of cheap dynamic mics (good enough for speech)
need amplifier
no batteries or phantom power needed

Backplate Condenser: These are the professional mics. They need phantom power (48V) for charging the condenser. They also need an amplifier, because their output level is low.

good sound quality
need phantom power (48V)
need amplifier
expensive

Electret Condenser: These capsules are cheap and result in a good recording quality. They don't need phantom power voltage. They need power for the FET (field effect transistor) that's inside. If you have such a mic with a battery in it, it is mostly because of the FET power, not because of an amplification circuit inside the mic. These mics are in all the consumer products like mobile phones, PC headsets and so on.

cheap (2 EUR for a capsule)
good sound quality
need amplifier
need power for the FET (1,5 - 15V)

Recommendation for do-it-yourselfers: Use electret condenser mic capsules, solder an amplifier for them which both amplifies the output level and feeds the power needed for the FET to the capsule. The one on http://www.geocities.com/ferocious_1999/md/micpreamp2.html was soldered and tested by Uwe Freese, and it works. There are some others available from www.elv.de and other sellers.

Recommendation for others: Buy some mic + preamp combination which can be plugged into a line in of any amplifier. Maybe such a commercially available combination needs a power supply and doesn't work with batteries. Some are very expensive. You might have some luck at http://www.giant-squid-audio-lab.com/. Also the Archos stereo microphone has a separate preamplifier and microphone, available for about €25. This preamplifier works with other microphones - the ones that do not work with plugin power or phantom power but with their own battery. The microphones sold as being a minidisc/DAT microphone with their own battery work fine.

What does not work: Don't use an amplifier thing that is simply connected between some mic cable without a battery or other power source. Maybe it sounds as if it could work, but I doesn't. If the piece of (expensive) electronic doesn't have a power source and your mic doesn't either, it does not work! A PC sound card or md player usually has a power output (same pin where the sound goes through, dc value) for feeding the FET of an electret condenser capsule (see above) (and this power could also used to feed a mic amplifier), but the Archos hasn't (it's a line in and no mic in!).

If you want to know more on microphone powering, read this: http://www.hut.fi/Misc/Electronics/circuits/microphone_powering.html. (As described, you also need amplification.)

I can't start rockbox on my Archos when the charger is connected. What am I doing wrong?

If your device is off and you connect the charger, the Archos charger code is started immediately. You can then start Rockbox with holding down the ON key for several seconds. Hold the key down a really long time, until you see the Rockbox logo!

Why can't you implement a cross-fader on the Archos? That would be so cool!

Please read our NODO faq. NoDo#3_Crossfade_between_tracks_

My screen is all black/white when I run Rockbox on my Recorder!

This bug has been fixed in the later versions of Rockbox. Upgrade!

Where are the FM controls for the FM Recorder?

In the menu: FM Radio

I installed/renamed ajbrec.ajz (or archos.mod) but I am still booting with another version of firmware.

When looking on the hard disk the Archos firmware only matches the first ten characters of the file name. Because of this files like ajbrec.ajz.bak or ajbrec.ajz-20030404 match and are loaded. To prevent this from happening, give the it a file name that differs in the first 10 characters, e.g., ajbrec.bak.ajz.

Help! My recorder crashes when I copy files to it!

Yes, the recorder can crash when you copy several gigabytes of files to it. The explanation is simple: Copying several gigabytes of files through USB requires a long period of sustained disk activity and drains more power than the batteries of the recorder can store. A long copy will eventually drain the batteries to the point where the recorder can no longer function and it halts. This even happens when connected to the charger, since the power drain is more than the charger can provide! If the recorder halts while connecter to the charger, the batteries will recover and after a short while it will reboot the Archos firmware in charger mode. To make it worse, depending on the USB drivers of your system it can cause your system to crash as well, or confuse it to the point it needs a reboot.

There is no solution, just some tips:

Connect to the charger when copying lots of files. This will not prevent the problem, but it will take longer to happen.

Make sure you have "Deep Discharge" disabled.

Switch off the "Backlight On When Plugged" option.

Use USB 2.0. Transfers will be much faster.

Copy incrementally. With fully charged standard batteries it should be capable of sustained copying for 2 - 2.5 hours.

What should I know about digital I/O connector on my Archos jukebox?

The Archos Recorder models have a connector for digital audio output using the common S/PDIF standard (Sony/Phillips Digital Interface). This jack is not present on the Studio/Player/FM Recorder models. By using the digital output in combination with high class external equipment, you can get much better sound quality out of your jukebox. This is because you can use better DA-converters and better amplifiers, plus you eliminate the analog audio connections between the jukebox and your equipment that can introduce noise and distortion.

The Recorder and the FM Recorder models are able to record from digital sources, too. The digital inputs don't have the 15kHz lowpass filter like the analog inputs and you are sure to minimize the noise floor.

Although S/PDIF can be an electrical or an optical signal and there are many devices that support both, the socket on the jukebox is for electrical signals only! Some devices have sockets that look the same, and can take either an optical or an electrical cable, but sadly this is not true with the Jukebox.

If you want to connect your amp with digital input (RCA type) to the output of your Recorder you need an adapter cable (3.5mm stereo jack to dual RCA jack). Plug the 3.5mm stero jack into the digital I/O socket of your jukebox and the red RCA jack (right channel) into the digital input socket of your amp and that's it. You don't have to enable the digital output, since it's always on. The sound settings on the digital output are always flat, your volume, bass, treble, bass boost, loudness settings won't have any effect here, that's why fade in/out won't work, either. The sampling frequency of the digital output is the same as the sampling frequency of the mp3. It's therefore possible that your external equipment won't be able to synchronize to the output of your jukebox if you have mp3's with sampling frequencies other than 32, 44.1 or 48kHz (The pitch shift function also modifies the sampling frequency!).

For recording digital signals on the Recorder, use the white RCA jack (left channel) and plug it into the digital output of your CD player, MD player or whatever. Don't forget to select digital input in the recording settings!

Note that some adapter cables exist with different color coding, so if it doesn't work try to swap red and white. The tip of the 3.5mm jack is the digital input, the ring is the ouput. For recording digital signals on the FM Recorder, you need a special 4-pole 3.5mm plug (shaft = ground, tip = left channel analog line in, first ring (next to tip) = right channel analog line in, second ring = digital in).

If you want to connect devices with optical inputs/outputs, you need a small converter box which converts your signal from electrical to optical (for digital output from the Archos) or optical to electrical (for digital recording in to the Archos).

What is the Recorder V2?

The Recorder V2 is essentially an FM Recorder without the radio. It looks and works like the FM Recorder except for the radio, and has LiIon batteries. It is meant to replace the older Recorder model. NOTE! The first V2 Recorders were in fact real FM Recorders with the radio parts still mounted. If you are lucky, the FM radio might work in your V2, try it!

Why is there a Radio option in my Rockbox for V2?

Some of the first V2 units had an FM radio in there, so if you're one of the few lucky ones, you can use the radio fine.

What does "dir buffer is full" mean?

It means you have more files in a single directory than you have configured Rockbox to support. See the GeneralFAQ for more information.

Solution: Increase the "max files in dir browser" setting.

The 2.2 release contained a bug that set the default buffer setting to 0, giving the dir buffer full error.

Solution: Upgrade to 2.4.

How do I control the recording frequency and quality?

Linus Nielsen Feltzing replied to a similar question on April 17th 2004, and this is a cut'n paste of his reply that can be read on the following URL: http://www.rockbox.org/mail/archive/rockbox-archive-2004-04/0814.shtml

SAMPLE RATE

Controls the amount of samples per second, basically which frequencies that can accurately be reproduced during playback. Lower frequencies produce smaller files, for two reasons: 1) The amount of data to be compressed is smaller and 2) the data is easier to compress, since higher frequencies are not present.

BIT RATE

Controls how many bits per second that is required for accurate live transmission of the compressed audio. When you compress the data harder (meaning worse sound quality), the bitrate gets lower.

STEREO VS MONO

A mono file doesn't necessarily have to be smaller than a stereo file. It all depends on the encoder. The MAS does produce smaller files with mono.

MAS QUALITY

The MAS uses VBR for compression (yes always), which means that the bitrate varies from frame to frame, depending on how compressable the data was at that point in time. This allows for a more even quality, and also smaller files if the data is easily compressed. The MAS can generate frames with bit rates ranging from 32kbit/s to 192kbit/s (MPEG1) or 8kbit/s to 160kbit/s (MPEG2).

The MAS quality setting is just a way of selecting an average bit rate according to the following table:

FREQUENCY/QUALITY	Q0	Q1	Q2	Q3	Q4	Q5	Q6	Q7
44100Hz stereo	75	80	90	100	120	140	160	170
22050Hz stereo	39	41	45	50	60	80	110	130
44100Hz mono	65	68	73	80	90	105	125	140
22050Hz mono	35	38	40	45	50	60	75	90

(This table can be found on page 38 in the MAS3587 data sheet.)

MPEG VERSIONS

The different MPEG versions use different sample rates:

44100, 48000, 32000	MPEG version 1
22050, 24000, 16000	MPEG version 2
11025, 12000, 8000	MPEG version 2.5 (not an official standard)

CategoryFAQ: Frequently Asked Questions about Rockbox for the Archos line of players

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