Christopher Drum has ported Infocom's Z-machine, specifically the Unix version 1.1, to a single executable using Cosmopolitan Libc. This allows classic Infocom text adventures, which were originally designed for various platforms, to run natively on modern operating systems (Windows, macOS, Linux, FreeBSD, OpenBSD, NetBSD) without emulation or VMs. The porting process involved minimal code changes, primarily focused on resolving system call discrepancies between the original Unix environment and Cosmopolitan's compatibility layer. This approach leverages Cosmopolitan's ability to build statically linked, universally compatible executables, effectively "resurrecting" these classic games for contemporary systems while preserving their original codebase.
Christopher Drum's blog post, "Resurrecting Infocom's Unix Z-Machine with Cosmopolitan," details his successful effort to port Infocom's classic text adventure game engine, the Z-Machine, to a variety of operating systems using the Cosmopolitan Libc. This porting process allows these vintage games, originally designed for systems like the PDP-10 and later ported to various 8-bit and 16-bit platforms, to run natively on modern operating systems including Windows, macOS, Linux, FreeBSD, OpenBSD, and NetBSD, all from a single executable.
Drum leverages the unique capabilities of Cosmopolitan Libc, which enables the creation of truly universal binaries capable of running across different operating system kernels without requiring emulation or virtualization. He explains that his motivation stemmed from a desire to play these classic text adventures without the complexities of setting up emulators or dealing with platform-specific binaries. Cosmopolitan provided a streamlined solution to this problem.
The technical process involved obtaining the original Z-Machine interpreter source code, specifically version 4, the last version released by Infocom, which was originally written in portable C. Drum adapted this code to compile with Cosmopolitan's build system. He meticulously addressed compatibility issues and made necessary adjustments to ensure the code interacted correctly with Cosmopolitan's system calls and APIs. This involved resolving discrepancies in how file I/O and other operating system-dependent functionalities were handled between the original code's assumptions and Cosmopolitan's environment.
A key aspect of this porting project is its emphasis on preserving authenticity. Drum aimed to retain the original game experience as much as possible. He highlights the success in achieving this goal, mentioning how the ported Z-Machine accurately reproduces the gameplay and feel of the original Infocom games.
Furthermore, Drum packages the resulting Z-Machine executable, along with the necessary game data files (commonly referred to as "story files" or "z-code files"), into a convenient, self-contained package. This packaging simplifies distribution and allows users to readily access and enjoy the classic text adventures on modern systems without any additional setup or configuration. He also addresses the legal aspects of the project, confirming the availability of the Z-Machine source code under a permissive license, ensuring the legality and open nature of his endeavor.
The blog post concludes with a demonstration of the ported Z-Machine running the classic text adventure game "Zork I" on different operating systems, showcasing the portability achieved through the use of Cosmopolitan Libc. This achievement signifies a revival of these classic games, making them easily accessible to a modern audience while preserving their original charm and functionality.
Summary of Comments ( 39 )
https://news.ycombinator.com/item?id=43677909
Hacker News users generally praised the project for its clever use of Cosmopolitan Libc to create truly portable Z-machine binaries. Several commenters expressed nostalgia for Infocom games and appreciated the effort to preserve them. Some discussed the technical aspects, like the benefits of static linking and the challenges of porting old code. A few users offered suggestions, such as adding features like save/restore functionality and improving the command-line interface. One commenter pointed out the potential for running these games on embedded systems thanks to Cosmopolitan's small footprint. The overall sentiment was positive, with many excited about the possibility of playing classic text adventures on modern and diverse platforms.
The Hacker News post "Show HN: Resurrecting Infocom's Unix Z-Machine with Cosmopolitan" sparked a discussion with several interesting comments.
One commenter expressed excitement about the project, noting the historical significance of Infocom and the Z-machine and praising the elegance of using Cosmopolitan Libc to create a single executable that runs across multiple operating systems. They specifically highlighted the advantage of not needing to compile separate binaries for different platforms.
Another commenter delved into the technical details, explaining how Cosmopolitan Libc achieves its cross-platform compatibility. They described how it leverages the common subset of system calls present in various operating systems, effectively abstracting away the underlying platform differences. This commenter also touched on the clever use of "polyfills" within Cosmopolitan to bridge any gaps in functionality between different systems.
A further comment focused on the practical implications of this approach. They appreciated the simplified distribution process made possible by having a single executable. This, they pointed out, makes it significantly easier to share and run the software, eliminating the complexities of managing platform-specific builds.
Several commenters reminisced about their experiences with Infocom games and the Z-machine, showcasing the nostalgic appeal of this project. These comments added a personal touch to the discussion, highlighting the lasting impact of Infocom's work.
A more technically-inclined commenter questioned the performance implications of using Cosmopolitan Libc. They wondered if the abstraction layer introduced any overhead compared to native compilation. However, another commenter countered this concern, arguing that the performance impact is negligible in most cases, especially given the relatively low computational demands of running a Z-machine interpreter. This exchange offered a balanced perspective on the potential trade-offs involved.
Finally, a commenter inquired about the project's license and its implications for distribution and modification. This practical question highlighted the importance of licensing considerations in open-source projects.
Overall, the comments on the Hacker News post reflected a mix of technical appreciation, nostalgic enthusiasm, and practical considerations. They demonstrated a genuine interest in the project and its potential to bring classic Infocom games to a wider audience.