The tape drives UNISERVO 12 (at the left and the right side) and UNISERVO 16 (center). Reading and writing is performed in blocks. To avoid data corruption (overlapping), the timings of the accleration of the band has to be very correct. While the "cheap" devices UNISERVO 12 control these operations electromechanically, the UNISERVO 16 features a pneumatically driven system. This is very heavy and expensive, but the drive is three times faster than the other.