+------------------------+
|  Overlay block number  | Start of overlay relative to start of file.
|                        | (Value is 0 if this is extra root information.)
+------------------------+
|     Overlay size       | Size of overlay in words.  (Value is 0 if this 
|                        | is extra root information.)
+-+----------------------+
| | Relative word offset |
+-+----------------------+
|    Text to relocate    |
+-+----------------------+
| | Relative word offset |
+-+----------------------+
|    Text to relocate    |
+------------------------+
.                        .
.                        .
.                        .
+-+----------------------+
| | Relative word offset |
+-+----------------------+
|    Text to relocate    |
+------------------------+