The Android Operating System
Android os is similar to Apple ios in that it is a layered stack of software that provides a rich set of frameworks for developing mobile applications. At the bottom of this software stack is the Linux kernal. More ...
Multiuser Operating System Functions
Some operating system functions like resource allocation, accounting, protection and security exist not for helping the user, but rather for ensuring the efficient operation of the system itself. More ...
Binary Number Representation and Binary Math
Computers perform all of their amazing work with only two voltage levels, one representing binary 0, the other representing binary 1. This article describes how to perform binary addition and subtraction. More ...
Capacitors in DC Circuits
A capacitor is a component that can be used to store an electrical charge. A capacitor can be used to create a timer. This time delay can be used to smooth a changing current flow in a circuit, or it can be used to absorb spikes and prevent false triggering of other components. More ...
First-Come, First-Served CPU Scheduling Algorithm
CPU Scheduling deals with the problem of deciding which of the processes in the ready queue is to be alocated the CPU. There are many different CPU scheduling algorithms. In this article we describe first-come, first-served scheduling. More ...
Logical Versus Physical Memory Addresses
Computers use logical and physical addresses to access memory locatiuons. The CPU generates logical addresses. At run-time the Memory Management Unit (MMU) maps logical addresses to physical addresses. More ...
AMD Sempron Processor
The Sempron replaced the Duron as AMD's budget processor. The socket A Sempron is basically an Athlon XP with half the cache. The socket 754 Sempron is a cut down version of the Athlon 64 processor with half the cache. More ...
Operating System File Management
The operating system abstracts from the physical properties of its storage devices to define a logical storage unit, the file. The operating system maps files onto physical media and accesses these files via the storage devices. More ...
Monolithic Kernel vs Microkernel vs Hybrid Kernel
An operating system consists of two parts, the kernel space which operates in privileged mode, and the user space which operates in unprivileged mode. More ...
Interrupt Request Lines (IRQs)
What happens when the CPU (Central Processor Unit) is busy doing something, like defragmenting the hard disk, and you press a key on the keyboard? An interrupt (IRQ) is a connection between a hardware device and the CPU. A hardware device uses it's assigned IRQ line to signal or interrupt the CPU when it needs attention. More ...
Expanding the Resources of Microcontrollers
In some cases it is possible that the internal resources of a microcontroller are insufficient. The solution to these situations is to add external components by creating an expanded microcontroller structure. More ...
Operating System Memory Management
Computers must keep several programs in memory, creating a need for memory management. Many different memory-management schemes are used. The operating system Keeps track of which parts of memory are currently being used, and moves data into out of memory, and allocates and deallocates memory as required. More ...
