[Coco] OS-9 Hex Editor?

[K. Pruitt]

Is there a  hex editor (binary file editor or byte editor) available for 
OS-9 files?  I'm fairly certain one exists as I have a program here to 
update the CRC values of modified files, and several of my programs show 
evidence that I made some modifications to them, and yet I don't seem to 
have one on any of my disks - at least not on any of those that still work.

Any info (like a file name) would be greatly appreciated.  Thanks.