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Mirror Magazine

Techno Page - By Harendra Alwis

Linux operating system
New and powerful computer hardware was pushing the limits of computing beyond anything that the dreamers of the past had been bold enough to imagine. Their comparatively reasonable prices had opened the gates of computing to millions of people worldwide.

But there was something missing. The operating systems were simply not capable of putting the magnificent power of the new hardware at the fingertips of their users. It was the time when MS-DOS reigned supreme, but it was still the age where the users wrote their own device drivers.

The year was 1991, the place; University of Helsinki, Finland. Young Linus Benedict Torvalds was busy in front of his computer. "I'm doing a (free) operating system (just a hobby, won't be big and professional...)" he wrote, on 25 Aug 1991, not knowing that his little "hobby" would make him the "world's most favourite and most famous programmer to this date".

What happened in the months that followed is history, but the result of it, the Linux (pronounced "Lih-nucks") Operating System has revolutionised the computer world and virtually turned it upside down. You and I may not feel its importance all that much, because we are all still fond of the (pirated) "Windows" CDs that are available for Rs 90 at the very most at wayside shops. We have to pay as much as US $ 200 for its licence. Linux is free! But hold on. The kernel, or the core of the operating system is free, as long as you get the source code with it and all that, but most "User-friendly" or rather "usable" versions of Linux don't come for free.

This is because versions of the Linux OS such as 'Red Hat' or 'Yellow Dog' have combined various 'value additions' such as applications and tools and packaged them all together, with the intention of making some money out of it (of course!). These are known as Linux distributions and should not be confused with the Linux kernel. The latest version of the Linux kernel is Version 2.4.18, whereas for example the latest Red-Hat Distribution is Version 7.3 and the latest SuSE Distribution is Version 8.

The versatility of the Linux OS is unmatched even in this era of XPs. Linux has also been adapted successfully for use in Alpha, Mac, PowerPC, and even for palmtops, a feat which is hardly matched by any other operating system. It has very few gimmicks and uses the processing power of the machines to the fullest. Best of all, nobody has yet bothered to write any viruses for systems running Linux, which not only means that you don't need to have a virus guard, but you can have complete peace of mind at the same time.

MRAM
You hit the power button on your television and it instantly comes to life. But do the same thing with your computer and you have to wait a few minutes while it goes through its boot-up sequence. Why can't we have a computer that turns on as instantly as a television or radio? The answer may lie in Magnetic Random Access Memory (MRAM) which has the potential to store more data, access that data faster and use less power than current memory technologies.

If MRAM chips are small enough and cheap enough, this new technology could be in computers and cell phones by 2004. The key to MRAM is that, it uses magnetism rather than electrical power to store data.

This is a major leap from Dynamic RAM (DRAM), the most common type of memory in use today, which requires a continuous supply of electricity which makes it inefficient. At a time when power is at a premium, electricity bills are soaring and we just made our way out of many months of agonising power-cuts, MRAM threatens to replace not only dynamic RAM, but also flash memory

The kernel
The kernel is the core of any operating system. It is around the kernel that the rest of the operating system properties revolve. Linux has a monolithic kernel which means it is one, single, large programme where all the functional components of the kernel have access to all of its internal data structures and routines.

The alternative is to have a micro-kernel structure where the functional pieces of the kernel are broken out into separate units with strict communication mechanisms between them. This makes adding new components into the kernel via the configuration process rather time consuming and difficult.

Say you wanted to use a SCSI driver that had not been built it into the kernel. You would have to configure and then build a new kernel before you could use the driver!
There is an alternative: Linux allows you to dynamically load and unload components of the operating system as you need them.

Linux modules are lumps of code that can be dynamically linked into the kernel at any point after the system has booted. They can be unlinked from the kernel and removed when they are no longer needed. Mostly Linux kernel modules are device drivers, pseudo-device drivers such as network drivers, or file-systems. You can either load or unload Linux kernel modules or the kernel itself can demand that the kernel daemon (kerneld) loads and unloads the modules as they are needed.

Quantum computers
In 1947, American computer engineer Howard Aiken said that just six electronic digital computers would satisfy the computing needs of the United States. Of course, Aiken didn't count on the large amounts of data generated by scientific research, the influx of personal computers or the emergence of the Internet, which have only fuelled our need for more and more computing power.

If, as Moore's Law states, the number of transistors on a microprocessor continues to double every 18 months, the year 2020 or 2030 will find the circuits on a microprocessor measured on an atomic scale. And the logical next step will be to create quantum computers, which will harness the power of atoms and molecules to perform memory and processing tasks. Quantum computers have the potential to perform certain calculations billions of times faster than any silicon-based computer. Scientists have already built basic quantum computers that can perform certain calculations; but a practical quantum computer is still years away. Write in and share your views.

Email: technopage_lk@yahoo.com

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