Tech billionaire Elon Musk and Microsoft CEO Satya Nadella recently had a one-on-one virtual meet on X where they announced the arrival of xAI’s flagship Grok 3 models on Microsoft Azure.

While welcoming Grok to Azure during the Microsoft Build developer conference, Satya Nadella took a moment to recall Musk’s early tech days.

“I know you started off as an intern at Microsoft," Nadella said while referring to Elon Musk’s stint as a Windows developer. “You were a PC gamer then-and still are," he added.

Responding to Satya, Musk smiled and said, “I actually started before Windows-with DOS. I worked on the earliest IBM PCs with MS-DOS. They had 128k of memory, and when it went up to 256k, that was a big deal."

Musk added that he used to program video games in DOS before moving on to Windows 3.1.

The conversation, shared by the tech leaders, provided a rare glimpse into Musk’s early programming background, just as the two tech moguls discussed AI’s future.

While sharing the video, Nadella wrote, “Grok is coming to Azure Foundry! Thanks @elonmusk for joining us at Build to talk about what it means for devs.(sic)"

Nadella hailed xAI’s Grok as “a family of models that are both responsive and capable of reasoning," adding that he’s enthusiastic about its potential on Azure.

Elaborating on his vision for the Grok 3.5 model, Musk mentioned it is designed to reason from first principles.

“If you’re trying to get to fundamental truths, it boils down to identifying axiomatic elements most likely to be correct-and reasoning from there," he explained, adding, “The focus of Grok 3.5 is fundamental physics and applying those tools across reasoning domains, aspiring to truth with minimal error."

This collaboration marks a key moment in the rapidly evolving AI landscape, as Musk’s xAI expands its reach through one of the world’s largest cloud platforms.