Installing Ubuntu 9.10 in Vista using VirtualBox

Often we need some software which are opensource and run in linux OS only. Dual booting your machine with Windows and Linux is one option. But just for one software switching between two OS is not desirable since we need to restart the machine every time. The best way out is to install Linux OS like Ubuntu in windows itself. To do this follow the steps-

1. Download and install VirtulBox. (http://www.virtualbox.org/wiki/Downloads).
2. Open virtual box. Select New. In OS select Linux from drop down list and then select Ubuntu.
   
3. Set the desired setting. It is desirable to give more RAM to virtual machine if you have RAM most of the time remains unused.
4. For hard disk you can either select static or dynamic drive. Dynamic drive is desirable.
5. Once all set select the machine and start for the first time mount the iso file of ubuntu desktop edition.
   
6. Machine will boot on it and follow the normal ubunut installation instructions.
7. After installation the machine will restart and you will see ubuntu inside the vista.
8. Ofter the screen size is fix and usually set to 800x600 which is not desirable.
9. Go to device -> Install device addons.
10. A cd rom will appear in your Desktop of VM (virtual machine). Run the following
    cd /cdrom
    sudo ./VBoxLinuxAdditions-x86.run
11. Once addon installation done press Ctrl+F and then Ctrl+G. Your are done. Enjoy
    

8051 Microncotroller

It is a good idea to start with the simple and most popular microcontroller 8051. The controller I am going to use is from Atmel AT89S52 microcontroller. I will start with small introduction then Assembly programing then we will use nice C compiler for programing. It cost around Rs60 and has some great features like-

Introduction

The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory.

Specifications

• Compatible with MCS®-51 Products
• 8K Bytes of In-System Programmable (ISP) Flash Memory
• Fully Static Operation: 0 Hz to 33 MHz
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Full Duplex UART Serial Channel
• Fast Programming Time

Before starting it is a good idea to get familiar with internal architecture of the microcontroller.

8051 family of microcontrollers are based on "modified Harvard Architecture" which means we have different memory location for data and instruction.

1. It has internal RAM to store data and Flash memory to store Instructions. Pins are provided to attach external RAM and ROM to the microcontroller. Separate address space is used to access both memory (as well as internal and external )which is encoded in instruction itself.
2. Bit wise addressing is also possible.
3. The upper part of memory consist of SPR (Special Purpose Registers)

Hardware Required

1. AT89S52 microcontroller.
2. Crystall