1.3.2.4 Allocation Map (AMap)

An Allocation Map page is a fixed-size page that is used to track the allocation status of the data section that immediately follows the AMap page in the file. The entire AMap page can be viewed as an array of bits, where each bit corresponds to the allocation state of 64 bytes of data. An AMap page appears roughly every 250 kilobytes in the PST (see the diagram in section 1.3.2). For more details about the AMap, see section 2.2.2.7.2.