You'll need to run Wadgen to extract the DOOM64.WAD and DOOMSND.SF2 files from the ROM.
I’ve finally got ready to go. For anyone who missed this back in 1997, this isn't just a port—it’s a full-blown sequel with completely new sprites, textures, and a much darker, atmospheric soundtrack. How to get it running: File: doom.64.zip ...
Use the password W93M P7W2 BCV1 L7X5 (or ?TJL BDFW BFGV JVVB ) to unlock the "Features" menu for level select and invulnerability. You'll need to run Wadgen to extract the DOOM64