Transformation of the PC

It has been less than 30 years since the computer became personal, but in that time it has undergone several major transformations as well continual evolution. Now personal computers are poised once again on the threshold of a major transformation that will alter the way we use them. As with each prior transformation, the result will be easier, faster, and more reliable operation; a PC better tuned to the needs of users.

The earliest versions of what became personal computers appeared in the early 1970s. These systems targeted electronic hobbyists, however, not the general public. They were electronic boards without enclosure, keyboard, or screens; only a calculator keypad and some numeric displays. No software was available for them. They needed to be programmed one instruction at time, using arcane numeric codes and could only do very simple things.

The first transformation came in the mid-70s when companies such as Apple and IBM began offering systems for use by the general public. These were the first true personal computers and came in a form that is still recognizable as a PC today. The electronics were fully enclosed and they had full keyboards attached or built-in. They used attached monitors (sometimes even televisions) as displays. More importantly, users could load fully-developed software programs and run them on these PCs. This turned what was an expensive toy into a device that could perform a useful function.

One of the keys to this transformation was the incorporation of a special program built directly into the PC. This program (software) was stored in an integrated circuit chip (hardware) and thus came to be called "firmware." The PC began executing this firmware as soon as the on-off switch was thrown.

The firmware's function was to prepare the computer for operation, to read what users typed on the keyboard, to display things on the monitor, and give the computer an ability to accept new programs for execution on demand. The firmware, developed by companies such as Phoenix Technologies, was called the Basic Input-Output System (BIOS) and formed the foundation upon which all further programming of the PC was built.

Rise of the OS

These early PCs used cassette tapes to hold the user's software programs and could only load and execute one program at a time. An alternative quickly arose, however, replacing the magnetic tape in the cassette with a flexible magnetic disk in a flexible housing - the floppy disk. Along with the advent of the floppy disk came the second transformation of the PC - the development of an operating system.

An operating system (OS) is a program that tells the computer how to handle the loading and execution of other programs as well as how to manage resources such as memory, input and output (I/O) channels, attached peripheral devices, and the like. One key feature of an OS is that it allows the computer to execute several programs concurrently. So, a program that sends information out to a printer can be running at the same time as one that balances a checkbook. This ability to do many things at the same time made the personal computer even more powerful.

The PC now had a multi-stage start-up sequence. Turning on power caused the computer to run the BIOS program, which in turn loaded the OS off of disk and ran it. The OS then allowed the user to load and run application programs off of disk.

Engineers compared the operation to pulling oneself up by ones bootstraps, and the term "boot" became the name of the whole sequence. Along the way, floppy disks became more compact and developed a hard shell (although the disk inside was still flexible), then were supplanted by built-in hard disk drives that could hold both the OS and hundreds of application programs.

Several different operating systems arose but only two survived in the market. One was the operating system used in Apple computers. The other was Microsoft's Disk Operating System - MS-DOS - also simply called DOS, used in the IBM PCs. Over time the IBM type of PC came to dominate the market, representing some 90% of all personal computers sold. For many, the term PC means an IBM-type computer.

These early operating systems required users to tell the computer what they wanted to do and which of many available programs on disk to run by typing in commands - often obscure words and abbreviations. Further, each program that wanted to use a printer or other attached device had to include code that could control the specific brand and model of device the user happened to have. These limitations created some problems for users as well as application software developers, but the overall improvement in PC usability was substantial.

Graphical Command Appears

The next transformation of the PC addressed those early OS limitations by changing the OS from a "command line" interface into a graphical interface that used pictures instead of words and mouse clicks instead of typing. The Apple and Microsoft DOS operating systems became the MacOS and Windows.

Users now could control their computers easily and intuitively through the "point-and-click" approach rather than by typing in computer language. Along the way, the OS created standardized ways of handling attached devices so that there was no longer a need to worry about an application having the right code for using a specific model of device.

The OS has undergone substantial evolution since then. Windows, for instance, went through Windows 3.1, Windows 95, Windows 98, Windows ME, Windows XP, and now Vista. At each stage the OS added more code to simplify the user's task, added applications code for functions such as email and Web browsing, and generally, became more complex.

So today's PCs offer an astounding array of built-in capabilities, even before a user adds applications programs such as games and word processors to their computer's repertoire. Unfortunately, this has come with increasing cost. The boot process, once only a few seconds long, can take many minutes to load all of the OS and its built-in applications. The memory and disk space needed to store and then to run this software has increased dramatically.

The many different pieces of code running concurrently just within the operating system have slowed down the computer's responsiveness and each application program added to the menu compounds the problem. As a result, the PC has become costly and sluggish and offers many more functions that most users will ever need. Also, this immense complexity has increased the likelihood that something will go wrong, preventing the computer from continuing to execute code - "crashing" - until it is turned off and re-started.

Virtualization: The Next Stage

Now, the stage is set for another transformation in the PC that will address these issues. The BIOS firmware that serves as the foundation for this OS and application software tower is about to undergo a fundamental change. Rather than loading the OS and transferring computer control to that program, the foundation firmware will retain control.

Using a software technique called "virtualization," this foundation firmware (no longer just a BIOS) will allow the OS to execute as though it had control while maintaining its own operation independent of the OS. In effect, the firmware splits the computer into the real machine, which it controls, and a virtual machine that executes the OS and all user applications.

This virtualization has several benefits. For one, it ensures that an error in the OS or application software does not halt the computer's operation. The foundation firmware will continue to operate even if the virtual computer crashes. This greatly simplifies recovery from errors without requiring re-boot of the computer.

Another benefit is that the firmware can prevent malicious software such as viruses from taking control of the computer. Because the firmware resides in a chip and cannot be altered by anything the computer does, no program that sneaks onto the PC can corrupt or compromise the firmware's operation.

The foundation firmware can also incorporate key application programs. Their location within the foundation means that they enjoy its protection, so no viruses or programming errors can damage or hijack them. The location also ensures that they are available for use as soon as the computer receives power. They do not need for the OS to finish booting up to become active. This means that users can access these programs instantly, without waiting.

Also, it is possible to create computers that use only this foundation firmware without any other OS, opening the opportunity for an extremely compact, lightweight, and inexpensive PC with a simplified set of applications.

The virtualization technology that is at the heart of this next PC transformation is coming from BIOS firmware pioneers like Phoenix Technologies and will soon be available for retrofitting existing computers as well as being built into the next generation of PCs. As with previous transformations, it is expected that the next generation PCs will be easier to use, more versatile, and be used even more often.