Removed dead links to Google Drive downloads. Added some clarifying text to make clear that this is only for CDI-format images. Added ROM/ISO information for the most common CDI version.
Super Mario Bros. DX is a complete graphics upgrade for Super Mario Bros., based partly on Super Mario Bros. 3 including a combination of directly-imported, modified, and entirely new graphics. Special attention has been paid to color. This hack may be combined with separate level hacks, or (if credited) used as a springboard for your own hacks.
Zip file includes a new 3.4 version as well as the previous major publicly released versions.