CHAPTER EIGHT

File Systems—FAT 12/16

WE ARE CONTINUING with the natural sequence of events of how data is stored electronically. We discussed the boot process and partition table to exemplify concepts of how data is stored on the hard drive. We follow the computer boot sequence, as it is the primary way in which data are “assembled” into information which we can use, or for which we may be searching as part of an investigation.

The next piece of “data assembly” is more logical in nature and actually brings data to a state in which we can actually access and use it. This chapter covers file systems and concepts related to the “mounting” of data into identifiable information.

TECH REVIEW

In the previous chapter we have started to cross the line between the physical storage of data and the logical storage of data. The definition of physical being the actual on/off state of the bit and its location on the hard drive platter, as defined by Cylinder, Head, and Sector (CHS) and Logical Block Address (LBA), with the partition defining the more physical boundary of data as they reside in the disk itself.

We discussed how contiguous physical bits are assembled together into physical constructs called sectors. Consecutive sectors are then logically assembled into what is called a cluster. As discussed, a cluster is a logical unit of storage which is made up of at least one sector.

When a file is saved it automatically receives a full cluster as a “container” for its storage. If the file ...

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