1.2 The binary system 3
called the boot loader which, in turn, launches the operating system. The boot
loader resides in the first partition of a permanent recordable medium, called
the boot sector or master boot record (MBR). If multiple media are present, the
BIOS searches through a pre-determined yet programmable list, and launches
the first available boot loader.
Dual-boot computers allow the alternative loading of multiple operating
systems with the help of an advanced boot loader such as the GRand Uni-
fied Bootloader (GRUB). GRUB Stage 1, residing in the master boot record,
launches GRUB Stage 2, residing anywhere in the disk. A menu of options is
then presented and the OS of choice is loaded.
Problem
1.1.1.Conduct an Internet search to compile a list of six operating systems
currently in use.
1.1.2.Conduct an Internet search to learn whether the BIOS also initializes
the mouse.
1.2 Thebinarysystem
Let us pretend that computers have not yet been invented and consider possible
ways by which information can be recorded and communicated by means of an
encoded protocol.
In the simplest method, a flag with a black and a white side is introduced,
and the black or white side is waved as many times as necessary to convey the
information unambiguously in lieu of a Morse code. A record of sequential
signals represents a string of binary digits 0 and 1, where 0 stands for white
and 1 stands for black.
The binary system thus provides us with a framework for describing num-
bers with binary strings. Once we know how to manipulate numbers, we can
proceed to handle letters of the alphabet by assigning to each one of them a nu-
merical code. Strings of letters form words, and strings of words form sentences,
instructions, and conclusions that can be true or false. A comprehensive system
may thus be built on the quintessential concept of the binary representation.
Bits
Computers work with the binary or base-two system of numbers that
uses the two digits 0 and 1 instead of the ten digits 0 – 9 of the more familiar
decimal or base-ten system. The number two is theradixof the binary system,