The Free On-line Dictionary of Computing (30 December 2018):

Commodore 1571

    Commodore Business Machines's "advanced" disk
   drive for the C128.  It was the double-sided version of the
   Commodore 1570 disk drive but, unlike the 1570, worked quite
   well.

   The 1571 supported "burst mode" loading when used on a C128
   in native mode, which increased the transfer speed from 1541
   speed to about three kilobytes per second (about a 10-fold
   increase).  The 1571 could be told to emulate a 1541 for use
   with a C64 or 1541 disks.

   Bugs in early releases of the 1571 ROM affected access to
   the second side of the disk.

   (1996-04-07)