The document summarizes the components and organization of a modern computer system. It consists of a CPU connected through a common bus to various device controllers that provide access to shared memory. Each controller manages a specific device type, like disks or graphics. The CPU and controllers can run in parallel competing for memory access. The initial bootstrap program stored in ROM loads the operating system kernel into memory to start system processes. Hardware and software can trigger interrupts that stop CPU execution and transfer it to a fixed location.

1. Computer System
Organisation

2. Diagram : Modern computer system
CPU
Disk
controller
USB
controller
Graphics
adapter
Memory
keyboard
printer
Monitor
Mouse
Disks

3. • A modern general-purpose computer system
consists of one or more CPUs and a number of
device controllers connected through a
common bus that provides access to shared
memory.
• Each device controller is in charge of a specific
type of device such as disk drives, audio
devices, or video displays.
• The CPU and the device controllers can
execute in parallel,competing for memory
cycles

4. • When it is powered up or rebooted , it will
need an initial programme, that is, bootstrap
programme.
• It is stored within the hardware in Read Only
Memory (ROM) or Erasable Programmable
Read Only Memory (EROM)

5. Initial programme
Knows how to load the operating system
how to start executing that system
Bootstrapprogramme
Location :
Operating System
kernel
Load: it is loaded in memory for
system process

6. • Hardware may trigger an interrupt at any time
• by sending a signal to the CPU, usually by way
of the system bus.
• Software may trigger an interrupt by executing
a special operation called a system call (also
called a monitor call).
• When the CPU is interrupted, it stops what it
is doing and immediately transfers execution
to a fixed location.