Prelude: Computing from Ancient Times to the Modern Era - The Technical and Social History of Software Engineering - page 24

Other inventions had a strong impact on the use of computers and hence on the
software that was created to support those uses. For example, without the 1960
IBM patent on a magnetic stripe that could be applied to plastic, credit cards would
not have been developed. Without the invention of magnetic ink, bank checks
would still be sorted alphabetically instead of in numeric order and probably sorted
by hand.
Key Inventions Relevant to Software
The inventions listed in the previous tables are all important in one way or another.
However, in thinking about the inventions that had the greatest impact on soft-
ware, the inventions discussed in the following section are the most critical.
Alphabetic Languages
Information recorded using pictograms such as Egyptian hieroglyphics is elegant
and beautiful and has produced some wonderful calligraphy, but such systems do
not lend themselves to rapid data entry and computerization. The same is true of
information recorded using ideograms such as Chinese and Japanese kanji (which
uses Chinese symbols). There are thousands of symbols, which makes typing ex-
tremely difficult.
During World War II, the text entered into the Japanese “Purple” coding ma-
chine actually used two American Underwood typewriters and plain text using
English characters. Alphabetic languages have the greatest speed for typed entry.
Binary and Decimal Numbers and Zero
Computers and software can process numbers using any base such as binary, octal,
decimal, or hexadecimal. However, electronic circuits for performing mathematics
are somewhat easier to design using binary arithmetic. Octal or base 8 numbering
systems are easily convertible from binary. (Some Native American tribes used
octal numbers since they counted by using the gaps between the fingers rather than
the fingers themselves.) Several computers were based on octal numbers such as
the DEC PDP line.
Hexadecimal or base 16 numbers are also used in computers and are convenient
because they match byte capacities. However, the bulk of day-to-day calculations
used by humans are based on decimal or base 10 numbers. Decimal numbers are
somewhat analogous to the QWERTY keyboard: not optimal but so widely used
that switching to something else would be too expensive to consider.