Public design package for the Raspberry Pi Compute Module IO board, revision 3.0, compressed as a ZIP of about 1.59 MB. Packages of this type usually bundle schematics, PCB layout or Gerber data and mechanical information released for carrier board developers, though check the extracted contents to see exactly what is included. It is useful for copying connector footprints, routing references and board dimensions into a custom design. Match the revision with your hardware, since V3.0 differs from earlier IO board releases.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @boardview. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.