Specifications

11
binary terms that is a mere “4.37GB.” Some groups have called for new terminology to define the “kilo
binary byte” as a “kibibyte” to distinguish it from a decimal “kilobyte” in order to reduce the confusion. The
last column above is the proposed list of new terminology to distinguish binary values. Others, ignoring the
heritage of IBM, Greece, and nature’s ten fingers, have claimed the storage industry is cheating the
consumer because the computer is always right. The difference between stated capacity of a medium and
what the computer claims it to be is compounded by formatting that takes up some of the capacity of
rewritable media. They need to reserve some of their capacity for file addresses and error correction, and
the media cannot be used unless they are formatted with that information first. The amount of capacity taken
up varies according to the software used to format the medium, but it can be a significant portion of total
medium capacity.
This reference guide will refer to the stated capacity of storage media in order to keep things as clear as
possible.
THE PROGRESSION OF SOLID-STATE MEMORY DEVICES
Flash media cards are the latest in a series of solid-state memory devices that have been around
for some time but are usually hidden within other products. What makes flash memory cards
distinct is the fact that they are removable and easy to erase, unlike their predecessors. In other
ways, however, they carry the vestiges of the types of memory chips known mainly to computer or
electronic engineers.
Bit lines
Word lines
Variable links
Chip Memory
=101
=111
=011
Memory chips all begin with the same basic design in their electronic circuitry formed in a grid
pattern (Fig. 3). One series of lines in the grid forms the computer binary words (8 bits in a word)
of digital data, and the other series of lines in the grid forms the binary bits that make up each
word. If there is a connection between the bit line and the word line where they intersect, the value
of that bit is 1. If there is no connection, the value of the bit at that point is 0. In the example in
Figure 3, the first line of an imaginary 3-bit word would be 101 because there is no link in the
middle, reading the word from left to right. The value of the next word line is 111 because all three
links are in place. The last word line has a value of 011 in binary form because there is no link
between the bit line and the word line at the first intersection. This is the fundamental way memory
chips work. With thousands of bit and word lines they can store tremendous amounts of
information. What is different about each type of memory chip is how the links are designed to
operate in each one.
Figure 3