Click above to get retro games delivered to your door ever month!

  Function 11H (decimal 17) searches the current directory for a specified
  directory entry. The name you specify to function 11H can contain the
  wildcard characters ? and *. The ? character matches any single ASCII
  character (as a wild card in a poker game matches any other card) and the
  * matches any string of characters, so DOS can match a name that contains
  one or more wildcard characters with several different directory entries.
  If more than one directory entry matches, DOS reports only the first
  match. You must then use function 12H to continue the search for
  subsequent matching directory entries.

  Before you call function 11H, store the address of an FCB in DS:DX. The
  filename field of this FCB must contain the name you want DOS to search
  for. DOS reports a successful match by returning AL = 00H; if no directory
  entries match the specified name, DOS returns AL = FFH. When DOS finds a
  matching directory entry, it creates a new FCB in the current disk
  transfer area (DTA) and copies the matching name from the directory entry
  into the new FCB's filename field.

  If the FCB has an FCB extension (see page 344), then you can specify the
  attributes of the file that you wish to search for. If you specify any
  combination of the hidden, system, or directory attribute bits, the search
  matches normal files and also any files with those attributes. If you
  specify the volume-label attribute, this function searches only for a
  directory entry with that attribute. With DOS versions prior to 2.0,
  neither the directory nor the volume-label attributes can be used in the
  file search operation. The archive and read-only attributes cannot be used
  as search criteria in any DOS release.