PCX
From Just Solve the File Format Problem
PCX was the native format of a DOS-based program PC Paintbrush, and was for a time (especially the late 1980s) a very popular image format among users of IBM PC compatibles and the PC/MS-DOS operating system. Much clip art was distributed in this format. However, it was tied closely to platform-specific attributes such as the particular graphic modes available in early PCs, and later lost ground to more platform-independent graphic formats like GIF, JPEG, and PNG.
Sample files
References
- PCX (Wikipedia)
- Format description (Game Modding Wiki)
- Page on PCX on fileformat.info, with some pseudocode