The movie was based on an excellent novel
by futuristic writer John Varley, which was an expansion of his 1977 short story entitled "Air Raid
." The novel is much better than the eventual movie. Some insight into the reasons for this were given by Varley in a 1992 interview with J. Stephen Bolhafner for the St. Louis Post-Dispatch. He said: "We had the first meeting on 'Millennium' in 1979. I ended up writing it six times. There were four different directors and each time a new director came in I went over the whole thing with him and rewrote it. Each new director had his own ideas and sometimes you'd gain something from that, but each time something's always lost in the process, so that by the time it went in front of the cameras, a lot of the vision was lost." The entire article can be found online here
. Another interesting insight on his experiences of working in Hollywood can be found in Varley's introduction to the original short story in this anthology
of his short stories that includes the original "Air Raid" short.