[MSDN Library June 1998] Horizontal Mouse Position in CGA and MCGA Modes (53.6702127659574%)

MSDN Library Visual Studio 6.0 > Knowledge Base > Microsoft Mouse Products

[MSDN Library June 1998] Horizontal Strip Running Across the Screen (51.8518518518518%)

MSDN Library Visual Studio 6.0 > Knowledge Base > Windows 95.x Retail Product