Last month, the tech world paused to reflect on a significant milestone: the 30th anniversary of Microsoft’s Windows 95, which made its debut on August 24, 1995. In a surprising twist, the Federal Aviation Administration (FAA) revealed in June that it still relies on Windows 95 and even floppy disks for its daily operations. This revelation comes alongside the agency’s commitment to modernize its systems, signaling a shift towards contemporary technology.
Despite Microsoft ceasing mainstream support for Windows 95 on December 31, 2000, the operating system continues to spark discussions, largely due to its pivotal role in popularizing Windows globally. While its graphical user interface (GUI) was often criticized for being a mere evolution of Windows 3.1, the system’s capabilities paved the way for richer graphical experiences in later versions.
In a fascinating exploration of Windows 95’s development, the “Old New Thing” series sheds light on one notable omission: the absence of a power-saving feature for idle laptops. Unlike modern iterations of Windows, which utilize advanced instructions like MWAIT (Monitor Wait) to efficiently manage power consumption, Windows 95 was developed during a time when such technologies were not yet available.
HLT would brick too many devices
Raymond Chen, a veteran engineer at Microsoft, elaborates on the decision to exclude the ‘HLT’ instruction from Windows 95. This choice was not made lightly; it stemmed from concerns that many laptops from a prominent manufacturer would become unresponsive upon booting if the CPU attempted to engage the HLT instruction. Users who sought to implement aftermarket components to enable power-saving features expressed their frustration, lamenting, “Stupid Microsoft. Why did they leave this feature out of Windows?”
“Since the failure mode is a system that is unusable, the cost of a false negative was far too high. We just had to remove the HLT.”
Raymond Chen, Veteran Microsoft Engineer
Chen further explains that the aftermarket components designed to execute HLT instructions were fraught with bugs, often leading to device freezes. He acknowledges that while it might have been feasible for Microsoft to implement a detection system for affected devices, the challenge of identifying all potential failures before Windows 95’s launch was insurmountable. Ultimately, the decision to omit the HLT instruction was a precautionary measure to prevent widespread system failures.
