What was the name of the 1975 magazine that inspired Bill Gates and Paul Allen to contact MITS?

Popular Electronics was the magazine whose January 1975 issue inspired Bill Gates and Paul Allen to contact MITS.

The issue featured the Altair 8800, a new microcomputer kit produced by Micro Instrumentation and Telemetry Systems, or MITS. Gates and Allen recognized that the machine needed software and decided to offer a version of the BASIC programming language for it.

They contacted MITS and claimed they had developed an Altair BASIC interpreter, even though they had not yet demonstrated it on an actual Altair computer. Allen later flew to Albuquerque with the software, which was successfully demonstrated to MITS president Ed Roberts.

That agreement became one of the earliest commercial steps toward Microsoft. The magazine article did not create Microsoft by itself, but it identified a new hardware opportunity that Gates and Allen quickly turned into a software business.