While researching the history of Microsoft’s segmented-executable linker originally called LINK4.EXE, I came across an OS/2 executable that was publicly released almost a year before the first OS/2 SDK was shipped, and many months before OS/2 was even announced. In fact the executable was likely released before the name “OS/2” even existed.
The file is EXEHDR.EXE, dated June 11, 1986 (size 32,896 bytes). It was shipped in the Microsoft Windows 1.03 SDK and then again unchanged in the Windows 1.04 SDK. For reference, OS/2 was announced on April 2, 1987 and the first OS/2 SDK was shipped around May 1987. Continue reading