The IBM 360 family, starting in the mid-1960s, introduced the idea of a standard memory cell of 8 bits called
the ???byte.??? Since then, computer manufacturers have come to advertise memory size as a count of standard bytes.
The idea of the computer word size is still with us, as it represents the number of bits the computer usually
processes at one time. The idea of word size has become less crystalline, however, because newer computer
designs operate on units of data of different sizes. The Intel Pentium processes 32 or 64 bits at a time, but it
is also backwards compatible to the Intel 8086 processor of 1980 vintage, which had a word size of 16 bits.
To this day, the Intel family of processors calls 16 bits a word, and in any case each byte has its own address in
memory.
Today the byte is the measure of computer memory, and most computers, regardless of word size, offer
???byte addressability.??? Byte addressability means that each byte has a unique memory address. Even though the
computer may be a 32-bit machine, each byte in the 4-byte computer word (32 bits) can be addressed uniquely,
and its value can be read or updated.
As you probably know, the industry uses prefixes to set the scale of a measure of memory.
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