Marcus’s disk ejected with a small brass key. He later found it opened a locker at a Greyhound station in Billings, Montana. Inside: a photograph of the tricycle from his Mars reconstruction, taken in 1975. On the back, in handwriting he recognized as his own but did not remember writing: “You were right to look up.”

Do you plan to install this on or a virtual machine ?

— a ghost in the stack

The only thing you will miss is the physical collectible disc artwork and potentially one or two ultra-rare binary blobs for obscure SCSI controllers.

The headline feature of the 5.1 ISO is its native support for . For the first time in the platform's history, an OS/2-based system can boot on modern PCs that run purely in UEFI mode without requiring a Compatibility Support Module (CSM) or "Legacy BIOS" emulation. Furthermore, ArcaOS 5.1 includes Secure Boot certificates, allowing users to keep Secure Boot enabled (critical for dual-booting with Windows 11), or disable it if necessary. This breakthrough essentially removes the largest obstacle preventing OS/2 from running on post-2020 hardware.

The legacy of OS/2, IBM’s iconic operating system, refuses to fade. For enterprise users running mission-critical legacy software and retro-computing enthusiasts alike, ArcaOS represents the definitive modern continuation of this legendary platform. Developed by Arca Noae, the highly anticipated release of the ArcaOS 5.1 ISO brings exclusive capabilities, bridging the gap between decades-old software architecture and cutting-edge modern PC hardware.