The word "native" is a little bit of a misnomer in this case, since it actually means a native boot of ColorForth on select instances of a Windows PC. This is NOT a native F18 boot image, since that is essentially what every version of arrayForth (
http://www.greenarraychips.com/home/support/download-02b.html) produces. Within arrayForth, you will find files with an extension of .cf, and every one of those contains a "native" boot image in the 1st 18 blocks. Chuck used those for a long time to boot from floppies on his personal computer. That computer died during one of his Forth Day fireside chats, and he had to switch to the Windows executable for the rest of his presentation. I suspect that he didn't go back, since finding a computer that worked with that image was becoming increasingly difficult. There were also some of us who managed to get various versions of ColorForth to boot in QEMU.