Well, I think I´m getting close to find why the memory seems to decrease.
To make long story short:
I formated an 512Mb USB pen drive using FAT16. Then I copied the Boot Sector, the Loader, and the partition master boot sector (I almost copied the whole thing) onto the s1 mp3 player USB drive. They were identical, so it was supposed to be recognized as an 512Mb drive instead of a 119Mb one. Right?
Althougth the geometry of the drive was now that of a 512Mb drive the system was still recognizing the darn thing as a 119Mb drive and refused to use it until formated.
Using Paragon Partition Manager I saw what may be the answer: the mp3 player was reporting the drive as having 15 Cilynders althoug it was supposed to have more as written in the disk.
From what I can gather, the s1 mp3 IS a computer, although with a different OS, it follows the rules set years ago for its internals (BIOS). In PC computers there is a table that defines the expected geometry of the hard drives. Today they do a check into the drive at boot time and report the correct geometry. This information is stored somewhere in memory so any programs, or OS can see what the parameters of a given disk are so it can managed it properly.
The firmware (or hardware) in the s1 mp3 players has that geometry written in it, so no matter what you do to the drive, the mp3 system will report allways the same thing: Cilynders, Heads (tracks), Sectors. That´s the reason why you cannot change the drive geometry ON the drive itself and get away with it.
This will also explain why som players refused to play after reaching the 128Mb limit: as reported by the internal HD table inisde the player, there is no more space available in the drive and since this error is not handle by the firmare, the player simply stops, restarts and shuts down.
My theory is this: The flash drives were formated to their right capacity at the time they were produced, for testing purposes, and they remained formatted after that. The problem side is that somehow the wrong firmare got into this players. The firmware for the 128Mb players got into the larger capacity players, problably by mistake.
That´s why you can see a 1Gb drive even thought you cannot stuff as much bytes in it. If you do, it will be written from the beguining every time it reaches its assumed capacity as told by the bios. This is normal to all media: floppy, hard disk, etc.
This also explains why the drive is initially formated as 1Gb or 512Mb and after decreasing, it cannot be formatted again to that capacity.
The solution seems to be to find WHERE in the player (firmware or Hardware) is this geometry table written. If it is in the firmware, the it will be a matter of changing it to the proper values. But if it is in the hardware, well that´s it. Nothing can be done. You either stick to your lower-than-paid-for-capacity mp3 player or returned for a refund.
I also think that unless this table is in the firmare that can be update, it will be very hard to find a compatible firmware for every player.
I´ll now try to get at the site that offers the two different firmware upgrades to see if the difference in the drive geometry can be found.
Whish me luck.
The site is at