The shareware version consists of the first 9 levels of the game.
: The original file ( DOOM1.WAD ) was built for MS-DOS and won't run natively on modern Windows. Doom 1993 Free Download
: You can find legitimate copies on historical archives like Internet Archive or community hubs like Doomworld . The shareware version consists of the first 9
Source ports are modern engines that use the original game data to run Doom with better resolution, controls, and compatibility. Doom 1993 Free Download