From: Linus Nielsen Feltzing <linus_at_haxx.se>
Date: Sat, 15 Feb 2003 05:33:02 +0100

Hello everyone!

We have a new hero in town!

Matthew P. OReilly wanted me to have a really great birthday so he
bought me a gift. An FM Recorder 20!!!

I am speechless! This is the most generous donation this project has
received so far. Now we can finally start reverse engineering the FM
Recorder.

I got it today, and immediately took it apart. My findings so far:

o The FM radio part is encapsuled in a box and hard to take apart. 8
   wires are connected to it:
    o The antenna, which goes to the ground on the headphones
    o The VCC
    o 4 wires go to PB0-2, (LCD control), and PB4 (the OFF button).
      The LCD pins can be used for radio control without interfering with
      the LCD as long as the LCD CS pin is high.
    o 2 wires go to the MAS INL and INR pins, obviously the left and
      right audio channels.

   My guess is that they use Samsung for the FM radio as well as
   the LCD controller, so it is probably the S1A0903X01. I will try
   to verify this by analysing the data on these 4 pins with a logic
   analyzer on monday.

o It uses 2 LiIon cells i parallel supervised by a Linear LTC1734
   battery charger.

o It has a Linear LTC1872 step-up DC/DC controller to generate 5V,
   probably for the disk drive.

o There is a serial EEPROM, looks like a Microchip 24LC02, that is
   connected to the ISD300. This is used for the ATA Identify block
   contents.

I will produce some schematics later on, along with detailed pictures on
the naked device. Stay tuned.

/The damn thing was pretty touch to take apart. I guess Archos' support
strategy is to replace broken devices rather than repair them...)

Time to sleep. Over and out,

/Linus
Received on 2003-02-15