AVR-Chat

>> > By the time you get as far as having all the code to read and write
>> > FAT and FAT32, I'm not sure if I'd call it "simple" anymore
>> -- we're
>> > talking thousands of lines of code!  But I agree that getting USB
>> > talking to a single peripheral is significantly simpler
>> than a general
>> > purpose USB stack.
>>
>> Thousands of lines ? Not at all. I've been working with FAT
>> for years, and it's not that complex.
>
> For top-level directories only, I would agree that reading and writing
> is not complex.  And it's even easier if you limit your partitions to
> use FAT12 or FAT16 only.  And it's even smaller if you limit your
> physical device to less than 32MB in total.
>
>> I even have a FAT capable bootloader in a mega8 ! About 750
>> bytes complete with CF card driver, programming and support routines.
>
> This would be a read-only system, though, with both FAT12 or FAT16
> support but not both, and probably limited to only reading files in the
> root directrory?  I can't see a complete FAT filing system in 750 bytes
> of code on an AVR.  I think Gus' code is a full file system, not a
> cut-down one and therein lies the difference.

It's obviously a reduced system, it's a FAT16/FAT32, read-only, short
filenames only and no directory handling, but it shows that FAT really
isn't that complex.
I have a full FAT16/FAT32 read/write system, with directory support and
long filenames that is just about 10-15K, and it includes fopen/fclose 
e.t.c.
support.

/J

> --
> Paul Curtis, Rowley Associates Ltd  http://www.rowley.co.uk
> CrossWorks for MSP430, ARM, AVR and now MAXQ processors