Re: [Libphidget-devel] serial numbers

[Jack S. <js...@ja...>]

On Wed, 2002-09-11 at 21:18, fit...@ph... wrote:
> 
> No maximum size.  It's defined in hardware as a string, so it would be the
> maximum length of a string in USB.  Probably 255 bytes or something.  In
> Windows, I'm representing the serial number with a long.
> 
> Vadim, we fetch a string, which is always string descriptor #3, for serial
> number, and then we parse this string to get the number.  This is the asm
> declaration for the string.
> 
> USBStringDescription3:
>      db Ch		; Length, db is a byte
>      db 03h		; 3 is a string descriptor
>      dsu "00001";	; string, defined in Unicode.
> 
> So you see that I'm using 5 digits only.  There is nothing to prevent me
> from stretching this when I reach 99,999.  Be nice if that change didn't
> break code.
> 
> Chester

So for example I get this back

12 - 3 - 48 - 0 - 48 - 0 - 55 - 0 - 52 - 0 - 49

12 bytes is the length of the message (does that include the first
byte?)

3 is the string descriptor

48 48 55 52 49  (unicode?) is 00741