@READY[d:]:  Returns 1 if the specified drive is ready; otherwise returns 0. The drive letter must be followed by a colon.

 

If the argument is a partial filename without a drive, @READY will expand the filename to get the drive.

 

@READY does not support UNC names.

 

Examples:

 

echo %@ready[E:]

0

 

echo %@ready[%_boot:]

1