Archive for February, 2010

Compiz in linux

Since the time, I’ve started using linux I always believed that ,one of the most attractive feature in linux desktop , 3d – desktop effects (compiz) are only meant for PC’s having only Intel micro-proceesor with high graphics-capability card.
Earlier in Ubuntu 8.04, whenever I tried to enable the visual effects it showed message like “3-d acceleration not supported”.

Thanks to Pramode sir, i realized that  the  graphics driver in debian (‘nv driver’) distro packages does not support my graphics chip.So I downloaded the required driver from the official site of the chip and installed it.

The first step to be taken for compiz installation is to identify whether compiz is supported on your system. This can be checked by executing  ‘compiz-check’ .It  can be downloaded from

http://forlong.blogage.de/entries/pages/Compiz-Check 

the information about your graphics card can accesed by command “lspci”,which  is  a  utility for displaying information about PCI buses in the system and devices connected to them.

lspci | grep ‘VGA’

will provide details  about graphics card in the pc like

00:0d.0 VGA compatible controller: XXXXXXXXXX

the graphics driver for the graphics chip can be downloaded from its official website

after that compiz can be installed by

apt-get install compiz

Configuring Compiz

The compiz can be configured by accesing CompizConfig Setting Manager from System->Preferences->CompizConfig Settings Manager
which opens like

One of the most attractive feature of the linux desktop is the 3d-desktop feature which if enabled helps to change the desktop into a cube,or a sphere or a cylinder according to the user needs.
Apart from this,the desktop can configured into a big cube or cylinder of water with fishes,sharks ,dolphins and tidal waves in it.Every thing in this in the configurable mode the frequency of the waves,height of the water,number of fishes and even the size of the fishes..
Some pics :

 

3 Comments

Programming a "PARALLEL PORT" in C using "inb " and "outb()"

   
                           For programming a parallel port in C,the user program is supposed to get the permission for accesing  the I/O port using the call

iopl(permission value)

which changes the previlege of the calling process.
By default the user program has a permission value of 0.So for accessing the parallel port,the user program  is supposed to have a permission value of 3

iopl(3);

  • outb()

For porting a value onto the parallel – port,the function outb() is used .

outb(value,0x378); 


parallel port the out pins are from 2 to 9 pin.


outb(value,portaddr);

will port a byte to the portaddr address.
the port address is to be selected as follows 

for 
/dev/lp0     ——    0x378 
/dev/lp1     ——–   0x3bc

 
a simple program in C to port a value to the parallel port


inb(portaddr)

parallel port register set


there are three main registers for a parallel port

  • status register
  • controll register
  • status  register

so these registers are used to read  the values of specific pins

the address of the status register
/dev/lp0 — >  0x378
/dev/lp1 — >  0x

4 Comments