The Birth Of RISC
The history of computing is replete with examples of innovations that were so successful they spawned entire industries. The personal computer revolution we are currently immersed in is one such example.
Born out of an era when users accessed computing resources through mainframes and terminals, PCs became a mass-market phenomenon thanks to the ability to create more user-friendly devices. In response, the industry developed alternatives to PC architecture that were cheaper, smaller and simpler to build.
RISC stands for Reduced Instruction Set Computer and typically refers to a type of CPU (central processing unit) design rather than an operating system or software package. However, RISC architectures have influenced the development of operating systems as well as other software products based on them. This article explores the history of RISC operating systems and their impact on future systems.
The Rise of CISC and RISC CPUs
A computer’s CPU is its “engine” that performs the steps necessary for software to function. This includes executing instructions, accessing system memory and storing data that software needs.
Early CPU architectures used a single instruction set (or CISC, for Complex Instruction Set Computer). This was efficient for some forms of software but inefficient for others, such as systems running multiple processes. These systems required more computer power and therefore larger, more expensive CPUs.
As the need for more powerful CPUs grew, computer engineers began developing CPUs that adhered to a different standard, RISC (Reduced Instruction Set Computer). A RISC CPU is designed to do less but perform the necessary tasks with fewer steps. This can improve the performance of computers and allow them to run at high speeds with low power consumption. RISC CPUs also tend to be smaller and more cost-effective to produce than CISC CPUs, which made them ideal for smaller and cheaper computer systems.
RISC OS: A Brief History
The 1980s saw the rise of PC-compatible machines that used CISC-based architectures. This meant RISC processors were relegated to a niche role in the computer industry. However, in 1988, Acorn Computers released a new type of operating system based on RISC architecture. Based around ARM architecture and known as RISC OS, this OS was designed for Acorn’s machines.
The RISC OS featured a graphical user interface (GUI) that allowed users to navigate the system and applications with a mouse. It also included support for networking and other advanced features that made it ideal for business use.
RISC OS soon attracted the attention of other computer companies and a group of them formed the RISC OS Open Ltd. consortium in 1991. This group intended to promote and share RISC OS technology by licensing it out to interested parties. Companies like Apple, Fujitsu and SCO were among the founding members of RISC OS Open.
However, the consortium disbanded in 2001, largely because RISC architecture failed to take off in the PC industry. Although RISC OS gained popularity in the early 1990s, it was soon eclipsed by the rise of Windows 95 and the Intel x86 architecture.
The Dawn of The RISC OS
While RISC OS failed to become the de facto standard for PC operating systems, it was adopted by a number of Unix-based systems. This included the Acorn system that originally ran RISC OS, which was rebranded as the RiscStation. The RiscStation was a Unix-like PC compatible machine that was released in 1993.
It was soon followed by other Unix systems that ran RISC OS, including the Liant/Scimed RES, the HP Risc 6000, the ICL Prima, the RS/6000, the SONY NEWS and the DEC VAXstation S/3600. These systems continued to use RISC OS long after the original RiscStation was discontinued.
The Decline Of The RISC OS
The adoption of RISC OS by Unix systems, though a positive sign for the OS’s survival, did not guarantee its long-term future. After all, Unix-like systems were already used as server platforms in data centers and academia. RISC OS was therefore always a secondary choice for organizations that already ran Unix-based systems.
This situation deteriorated with the rise of Linux, which became a popular open-source alternative to Unix. This, coupled with the decline of the PC market, resulted in the slow death of RISC OS. The last company to use the OS in a PC-type device, ICL, discontinued its use in 2003.
RISC OS In The Modern Era
Despite the death of RISC OS in the PC market, it has not been forgotten. A group of independent developers have continued to support the OS, releasing new versions and patches to keep it current. Additionally, the popularity of retro computing has led to a revival of interest in RISC OS. Fans have kept the OS alive in the form of retro computers such as the Pi-Top, the Pi-Bot and the Pixel-Top. Others have taken advantage of cheap microcontroller boards such as the Raspberry Pi, Arduino or other single-board computers to create new RISC OS-based devices.
This renewed interest in RISC OS is likely to help it survive in some form for years to come.
Final Thoughts
The RISC OS remains an important part of computing history. Its influence on the development of other operating systems, such as Linux, is undeniable. Likewise, its impact on computing culture is evident in the retro computing community, which continues to promote RISC OS to this day.
Indeed, these groups have helped keep the spirit of RISC OS alive during its extended period of dormancy. As such, they have ensured that this important computing milestone is not overlooked or forgotten.