List of unsupported firmware

List of discontinued firmware by Apple Inc.

The following is a list of firmware that expired long ago.

iOS

 * 4.0
 * 4.0.1
 * 4.0.2
 * 4.1
 * 4.2
 * 4.2.1
 * 4.2.5
 * 4.2.6
 * 4.2.7
 * 4.2.8
 * 4.2.9
 * 4.2.10
 * 4.3
 * 4.3.1
 * 4.3.2
 * 4.3.3
 * 4.3.4
 * 4.3.5
 * 5.0
 * 5.0.1
 * 5.1
 * 5.1.1
 * 6.0

iPod classic

 * 1.5
 * 2.3
 * 3.1.1
 * 1.2.1
 * 1.3
 * 1.1.2

iPod nano

 * 1.3.1
 * 1.1.3
 * 1.1.3
 * 1.0.4
 * 1.0.2