Dave Ahl has posted to his Facebook page that
PUBLIC DOMAIN. This is a public notice that I am formally placing everything that I have written or edited into the Public Domain. That includes material that may or may not have a copyright issued to David Ahl, Creative Computing Press, Ahl Computing, Ideametrics, SBI, DEC, Military Vehicles, Ziff-Davis, or SwapMeetDave. My desire is that this material be used for educational and historical purposes and not for profit or personal gain of others. (I did this years ago, but someone wanted a public notice, so this is it.)
I will be making all Creative Computing and Dave Ahl stuff available for download.