Windows 95 has gone the extra mile to ensure compatibility of SimCity, other games

It is still possible to learn a lot of interesting things about older operating systems. Sometimes these things are already documented (on a blog post) that miraculously still exist. One such quirk surfaced recently when someone noticed how Microsoft made sure that SimCity and other popular applications ran on Windows 95.

A recent tweeted by @Kalyoshika highlights an excerpt from a blog post by Fog Creek Software co-founder, Stack Overflow co-creator, and longtime software blogger Joel Spolsky. The most important message is about the appeal and demand for chicken-and-egg operating systems/software. The part that caught the attention of a Hardcore Gaming 101 podcast co-host is how the Windows 3.1 version of SimCity worked on Windows 95 system. Windows 95 merged MS-DOS and Windows applications, upgraded APIs from 16-bit to 32-bit, and was hyper-commercialized. A popular app like SimCitywhich sold over 5 million copies, was to run smoothly.

Spolsky’s post sums up how SimCity became ready for Windows 95, as he heard, without Maxis intervention or user workarounds.

Jon Ross, who wrote the original version of SimCity for Windows 3.x, told me that he accidentally left a bug in SimCity where he read the memory he had just freed. Yeah. It worked fine on Windows 3.x, because the memory never went anywhere. Here’s the amazing part: on beta versions of Windows 95, SimCity did not work in tests. Microsoft tracked down the bug and added Windows 95 specific code that searches for SimCity. If he finds SimCity while running, it runs the memory allocator in a special mode that does not free memory immediately. It’s the kind of obsession with backwards compatibility that drove people to upgrade to Windows 95.

Spolsky (in 2000) considers this an honor for Microsoft and an example of how to solve the chicken-and-egg problem: “providing a backward compatibility mode that delivers either a truckload of chickens or a truckload of eggs, depending on how you look at it, sit back and rake the dollars.

Windows developers may have deserved some time to sit down, given the extent of tweaks they often have to make to individual games and applications in Windows 95. Further down in @Kalyoshika’s answers you can find another example, taken from the Compatibility Administrator in Windows’ Assessment and Deployment Kit (ADK). A screenshot by @code_and_beer shows how Windows NT, when detecting files typically installed with Final Fantasy VII, will implement a compatibility fix aptly titled: “Win95VersionLie”. Simply telling the game it’s on Windows 95 seems to fix a major problem with how it works, along with a few other emulation and virtualization tweaks.

Install the Windows ADK and open the Compatibility Administrator, and you can spy on some of the things Windows does for particular apps to make them work in the System Database section. If it detects files named “Horny.tif” and “bullfrog.sbk”, it updates where Windows 95/98 versions of Keeper of the dungeon should put these files in Windows XP and later. Windows must shut down Tom Clancy’s Rainbox Six accessing the CD drive while playing a movie or other media, as well as disabling Alt+Tab switching while the game is open because the game cannot handle losing focus. And it’s not just older titles; Street Fighter V gets a small tweak to its DirectX implementation to work on some systems.

In 2005, longtime Microsoft employee and The Old New Thing blogger Raymond Chen documented Microsoft’s obsession with Windows 95 compatibility. Chen writes that the Windows 95 developer “took his van, drove to the local Egghead software store (back when Egghead still existed), and bought a copy of every PC program in the store.” Everyone was responsible for up to two programs, which they installed, ran, and documented for bugs. If a staff member completed two, they could come back to collect up to two more. And the testers could keep whatever they finished.

Mike Perry, former creative director of Simulator empire Maxis (and later EA), noted later that there was, technically, a 32-bit Windows 95 version of City Sim available, as seen in the game’s “Deluxe Edition” bundle. It also states that Ross worked for Microsoft after he left Maxis, which would further explain why Microsoft was so keen to make sure people could keep building parks in the perfect grid position to improve resident happiness.