UNISERVO I

The UNISERVO used metal tape: a 1⁄2-inch-wide (13 mm) thin strip of nickel-plated phosphor bronze (called Vicalloy) 1200 feet long.

Making allowance for the empty space between tape blocks, the actual transfer rate was around 7,200 characters per second.

[2] The UNISERVO supported both forward and backward modes on read or write operation.

The tape motion in the UNISERVO I was controlled by a single capstan connected to a synchronous motor.

Ironically, IBM then later switched to phase encoding in its 1600-bit-per-inch tape generation because of its superior data reliability.