IBM F50 RS/6000 7025 - Manual (Page 63)

Using the 4.0GB 4-mm Tape Drive
The optional 4.0GB 4-mm tape drive is a half-high device.
Status Lights
The 4.0GB 4-mm tape drive has two green status lights and one amber status light.
The on and off combinations of the status lights indicate the conditions of the 4-mm
tape drive.
Each of the International Organization for Standards (ISO) symbols located over a
status light indicates a specific condition of the tape drive as follows:
Chapter 2. Using the System Unit 2-37