Information Technology Reference
In-Depth Information
Where are
programs and
data stored?
AS WITH THE representation of data, many applications make
the details of program and data storage transparent to users as they
run programs. Thus, when running a program, we rarely worry
about where the program was stored, how main memory is allo
cated for our work, or how data move into main memory or the
CPU. Similarly, when we save a file from a word processor, spread
sheet, database, or Web browser, we normally do not think much
about where on the disk the material is stored or, when we open a
file, how the machine knows where to look for it. However, it is
natural to wonder how these materials are stored and retrieved.
Sometimes a basic understanding of such matters can guide us in
getting work done efficiently. Also, such background leads to a
consideration of viruses—undesired programs that often are ob
tained as parts of another stored program or data file. This chapter
reviews some basics of program storage, data storage, and viruses
and considers how we can use this knowledge in our regular use of
computers.
Chapter 1 began an answer to this question by describing basic
functions of the CPU and its registers, cache memory, main memory,
and I/O devices—all connected by a bus. Addressing this question
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