Subject: More info re: U3
To: Steven M. Bellovin <>
From: Dave J. Barnes <>
List: netbsd-users
Date: 09/18/2006 14:11:29
>> I didn't know that you could write to the CD-ROM part of the U3. Investigating.....
> I don't know how one does, but the contents get there somehow, and I'd
> hate to have to find a Windows machine to use as an SDK platform. 
I do not know what the USB command structure is for telling the existing 
firmware how to divide the FLASH cells up for
R/W and CDROM. USB sniffer anyone? After many complaints, U3 made a 
utility available for erasing and/or updating the CRROM like partition. 
For Windows only of course:(

There is no need for a special FLASH FileSystem since the U3 cpu does 
FLASH write wear-levelling, ie.

    "When a file must be updated, TrueFFS does not overwrite the old
    data. Instead, it writes the new data to unused blocks and directs
    subsequent read accesses to these blocks. The old data is marked as
    "old", and is not erased until the block has to be reused."

Hmmm. You could run an O/S on the U3 without fear of wearing out a FLASH 
cell. No rotating disk drive needed.

Since the Sandisk U3 (oem == M-Systems mDrive has an ARM7 CPU it could 
run an embedded version of NetBSD.
Wouldn't that be weird! Get those hackers warmed up:) (I wonder how much 
RAM and FLASH ROM the ARM7 CPU has.)