RISC OS Open's Moonshots Initiative: Transitioning from 32-bit to 64-bit Architecture

RISC OS Open has long been a beacon for computing purists—those who appreciate an OS that’s as lean and elegant as it is ingenious. Now, with its Moonshots initiative, the team behind this venerable operating system is gearing up to make a historic transition: a full-blown migration from 32-bit to 64-bit code on Arm hardware. This ambitious push isn’t just a technical upgrade; it’s a quest to preserve and modernize one of the very few living relics of early computing.

A Storied Past: The Legacy of RISC OS​

RISC OS isn’t just another operating system; it’s a living piece of computing history. Born as Arthur in 1987 with early Acorn computers, it was later rechristened RISC OS as the platform evolved. This was well before many of the operating systems we take for granted today came into being. The design principles of RISC OS—the minimalism, the directness of its graphical interface, and its efficient performance on limited hardware—remind us of an era when every byte of memory counted.

• Originally designed for Arm processors in an era of 26-bit addressing, it was built to squeeze maximum performance from modest hardware.
• The shift to 32-bit computing was already a challenging evolution, requiring careful work to maintain application compatibility and to extend support beyond the original 64MB physical RAM limit.
• Yet despite its age, RISC OS has managed to maintain a loyal following, offering a desktop experience that many consider second only to the elegance of classic MacOS.

Key Points:

• RISC OS began as Arthur in 1987 and evolved into a full-featured desktop OS.
• Its heritage of lean and efficient design is both its charm and its challenge.
• The OS’s evolution has always been about balancing innovation with backward compatibility.

Modern Needs Demand Modern Instruction Sets​

Fast forward to today, and the hardware landscape has shifted dramatically. Modern Arm processors—like those powering the Raspberry Pi 5—are built entirely for 64-bit operation at the kernel level. Unlike the x86 world, where backward compatibility allows 64-bit processors to run decades-old 16-bit and 32-bit software, Arm’s modern incarnations are streamlined for performance and power efficiency.

• Most contemporary Arm cores offer only limited or even no support for legacy 32-bit code.
• This means that without a native 64-bit version, RISC OS could soon find itself increasingly stranded on older hardware.
• A stark contrast exists with the x86 architecture that clings to backward compatibility as a point of pride, even as it accumulates legacy baggage.

By embracing a full migration to a 64-bit instruction set, RISC OS aims to shed this historical baggage and ensure that it remains relevant in a world where efficiency and modernity are paramount.
Key Points:

• Modern Arm hardware generally supports only 64-bit code, leaving legacy 32-bit systems behind.
• The x86 architecture maintains backward compatibility, but this luxury is not afforded to most Arm designs.
• The transition is not just about keeping pace—it’s about survival in a rapidly evolving technological landscape.

The Moonshots Initiative: An Ambitious Leap Forward​

Enter the Moonshots initiative—a new funding drive and development program launched by RISC OS Open Limited (ROOL) to spearhead the transition to Arm64. This isn’t merely a bug bounty program for tweaking a few features; it’s a full-scale modernization project that calls for transformational changes at the core of the operating system.

• ROOL’s open letter, penned by CEO Steve Revill, lays out an honest roadmap: a dedicated team of developers will need to work full-time over several years to execute this monumental task.
• The initiative isn’t just about rewriting code; it’s about rethinking RISC OS at its very foundation. The plan is to transition from a system crafted almost entirely in hand-coded assembly language to one written in a higher-level, portable language such as ANSI C.
• Early industry interest is already evident. There are murmurs of support and even offers from entities with automation tools for assembly-to-C translation, which could potentially reduce what Revill referred to as a “big ticket” challenge to something more manageable.

Benefits of the Moonshots Initiative:

• Secures sustainable support for the long-term development of the OS.
• Opens the doors for fresh community contributions and industry collaboration.
• Paves the way for future platforms—like a native RISC OS version for the Raspberry Pi 5—to see the light of day.

Key Points:

• The Moonshots initiative is a call to arms—seeking funding, expertise, and community backing.
• Transitioning from assembly to ANSI C represents a radical modernization of the OS.
• Industry collaboration could significantly ease the transition workload.

Rewriting History: The Technical Odyssey from 32-bit to 64-bit​

Although the leap from 26-bit to 32-bit addressing once presented significant challenges, the move to 64-bit involves a different magnitude entirely. In those earlier days, the transition was more a recalibration of memory addresses rather than a complete architectural overhaul. However, the jump to 64-bit requires rewriting the core instruction set from scratch—a task that is akin to replacing the engine of a vintage car with a state-of-the-art hybrid system.

• The inherent differences between the 32-bit Arm instruction set and the 64-bit Arm architecture are profound; the latter adopts a cleaner, MIPS-like RISC approach that doesn’t carry forward many legacy quirks.
• Developers will face the arduous task of re-engineering critical OS components, ensuring that every pointer, every flag, and every bit of memory addressing conforms to the demands of a 64-bit environment.
• The project’s scope means not only retaining the spirit and aesthetic of the original OS but also transforming its codebase to deliver enhanced stability, improved security, and better support for modern multi-core processors.

This transformation is not merely a technical update—it’s a reinvention of the OS’s soul. For enthusiasts and longtime users of RISC OS, the rewrite is an opportunity to preserve the operating system’s iconic charm while pushing it into modern computing realms.
Key Points:

• Moving to 64-bit is a more radical transition than previous upgrades.
• The process demands rewriting a significant portion of the OS to adhere to a new instruction set.
• The overhaul aims to enhance security, stability, and performance on modern hardware.

Implications for the Broader Computing Landscape​

While RISC OS has always occupied a niche corner of the computing world, its evolution holds lessons for the entire industry—including Windows users. At a time when operating systems are often burdened by bloat and backward compatibility concerns, RISC OS’s philosophy of minimalism and lean design is a refreshing counterpoint.

• Microsoft’s Windows operating systems have been evolving with regular updates, such as Windows 11, focusing on modern hardware and enhanced security. Yet even Windows struggles under the weight of legacy code and historical compatibility.
• RISC OS’s journey underscores a broader trend: the need to periodically let go of legacy constraints to embrace the efficiencies of modern computing architectures.
• For Windows power users and IT professionals, understanding these transitions offers a window into the trade-offs between historical compatibility and streamlined performance.

By modernizing RISC OS, the open-source community isn’t just preserving a piece of computing history; it’s paving the way for a new era of operating systems that prioritize speed, efficiency, and a no-nonsense design ethos.
Key Points:

• RISC OS’s evolution is instructive for operating systems at large.
• The struggle to balance legacy support with modern performance is a universal challenge.
• The initiative offers inspiration for a leaner approach to OS design, even for mainstream platforms like Windows.

The Community’s Role: A Collaborative Effort​

No modern technological renaissance happens in isolation. The Moonshots initiative is a call for community support—not only in terms of funding but also in securing volunteer developers and fostering collaborative innovation. The transition to 64-bit is a project that benefits from the diverse skills and experiences of the community.

• Open-source communities thrive on the shared passion of their members, and RISC OS’s loyal user base is a testament to that fervor.
• Innovations like the assembly-to-C translation tools mentioned in the open letter are emerging from various corners of the industry, showing that when passionate minds unite, even the most daunting challenges become surmountable.
• By rallying community support, RISC OS Open hopes to ensure that the modernization process remains transparent, collaborative, and, ultimately, successful.

This grassroots spirit is essential—not only to retool an operating system that has seen better days but also to keep alive the ethos of open and innovative software development in an era dominated by corporate giants.
Key Points:

• Community collaboration is central to the Moonshots initiative.
• Grassroots support can drive complex projects to fruition.
• The initiative is a celebration of the open-source spirit and collective innovation.

Spotlight on Pyromaniac: RISC OS in the World of Emulation​

In an intriguing twist that underscores the versatility of RISC OS, the article also highlights Pyromaniac—a project designed to implement RISC OS from scratch using Python, complete with Arm emulation. While the code isn’t publicly available, the project demonstrates that creative approaches to preserving and modernizing legacy software are alive and well.

• Pyromaniac offers both 32-bit and 64-bit environments, complete with a desktop experience, available via a cloud-based command-line interface for Linux, macOS, and Windows users.
• Developed by Gerph, a veteran who was involved in earlier iterations of RISC OS, this experimental project reinforces the idea that innovation doesn’t always follow a conventional path.
• For Windows users and developers intrigued by operating system design, Pyromaniac is a testament to the enduring allure and flexibility of RISC OS.

Key Points:

• Pyromaniac illustrates the creative efforts to run RISC OS on non-Arm systems.
• It serves as both a practical tool and a proof-of-concept for future development.
• The project highlights the enduring impact of RISC OS on software innovation.

Looking Ahead: The Future of RISC OS and Beyond​

RISC OS isn’t just fighting to keep pace—it’s launching itself into a new era. By embracing a modern 64-bit architecture, the operating system plans to reclaim its place on the cutting edge of technology. This transition, if successful, could pave the way for native versions of RISC OS on modern platforms like the Raspberry Pi 5, ensuring that the OS remains both usable and competitive.

• The Moonshots initiative, with its ambitious roadmap and community-driven funding model, promises to be more than a mere upgrade—it’s a reinvention of what RISC OS can be.
• For IT professionals, enthusiasts, and even Windows users, the effort exemplifies what can be achieved when legacy software is rejuvenated for a modern world.
• It’s a reminder that in technology, sometimes the boldest moves come from rethinking the fundamentals rather than simply iterating on the past.

As we watch this exciting project unfold, we’re left to ponder: Can a relic from the 1980s truly reinvent itself and stand against the juggernauts of modern computing? The answer may lie in the passion of its community and the ingenuity of its developers—a combination that has, time and again, transformed challenges into milestones.
Key Points:

• The successful migration to 64-bit could rejuvenate RISC OS and open doors for new hardware support.
• The initiative is a bold example of how legacy systems can evolve with modern technology.
• The project invites us all to reflect on the balance between historical legacy and technological innovation.

For Windows users accustomed to the regular cadence of Windows 11 updates and Microsoft security patches, the story of RISC OS’s modern transformation is both a technical and philosophical reminder. It speaks to the enduring struggle for efficiency and elegance in an environment increasingly cluttered by legacy code. While the OS under discussion may not directly impact the Windows ecosystem, its journey from 32-bit purgatory to a vibrant 64-bit future is an inspiring nod to the relentless, ever-evolving spirit of technology.

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Source: theregister.com RISC OS Open plots great escape from 32-bit purgatory