Code archaeologist online unearths the origins of MS DOS

A code archaeologist has unearthed a treasure trove for tech historians: the oldest known ancestor of Microsoft's iconic MS DOS. This discovery, 86 DOS version 0.1 C, hails from the early days of computing, shedding light on the humble beginnings of the operating system that revolutionized the PC industry.

The story begins with Tim Paterson, the mind behind QDOS ("Quick and Dirty Operating System"), which was developed in 1980 at Seattle Computer Products (SCP). QDOS christened after the Intel 8086 processor, which caught Microsoft's attention. An Internet Archive user, f15sim, discovered and of 86 DOS to the Internet Archive.

Version 0.1 C of 86 DOS is available for download and can be run using the SIMH emulator; before this, the earliest extant version of 86 DOS was , also uploaded by f15sim. This primitive iteration of the operating system, now available for download on the Internet Archive thanks to the efforts of Gene Buckle, offers a captivating glimpse into computing's past.

Buckle, renowned for his passion for vintage code, shared his excitement about this remarkable find. "A few years ago, I was given a massive collection, and only recently have I been able to dig into it seriously," he explained. Among the treasures he uncovered were several disks containing different versions of 86 DOS and MS DOS, showcasing the evolution of these foundational systems.

"I thought finding the 0.34 version was cool," Buckle remarked, "but stumbling upon 0.1 was unexpected." His enthusiasm doesn't stop there, hinting at more discoveries awaiting upload: "I've got more originals to share, including a comprehensive set of MicroPro products and CompuPro operating system disks.

Brace yourselves for a dive into computing history. Bridging the gap in software compatibility The significance of this finding lies not only in its rarity but also in dispelling myths. Contrary to popular belief, QDOS and 86 DOS didn't stem from CP/M source code. Instead, Paterson crafted 86 DOS for SCP's 8086 hardware from scratch, utilizing API references from CP/M manuals.

It was a deliberate creation rather than a reverse engineered replication. Moreover, 86 DOS was engineered to bridge the gap between the 8086 and the established CP/M system, easing the transition for software compatibility. This early version, even equipped with a translator for CP/M programs, demonstrates the foresight behind its design.

The tech community eagerly anticipates further uploads, as Buckle's collection promises deeper insights into the evolution of computing. As enthusiasts dive into these artifacts, they're unraveling the threads that weave the rich tapestry of computing history. This discovery not only adds a crucial chapter to the story of MS DOS but also serves as a testament to the ingenuity and foresight of early developers.

It's a reminder that the tech landscape we navigate today has deep roots reaching back to the innovative efforts of pioneers like Tim Paterson and the team at SCP..