Central storage is physically divided into storage elements (SE).
The central storage elements are composed of storage increments.
Each storage increment may be composed of two sub-increments:
- One sub-increments contains the even-numbered frames of the increment, such as, 0-kilobyte, 8-kilobyte, 16-kilobyte, and so on.
- The other contains the odd-numbered frames, such as, 4-kilobyte, 12-kilobyte, 20-kilobyte and so on.
The sub-increments of an increment may reside in different storage elements, as follows:
