For those who may wonder, as of the date of this posting here are the digital channel mappings for the various high definition channels Comcast (Chicago, north side) offers over clear QAM. These channels will be available if you directly connect a coaxial cable to an HDTV with a clear QAM tuner. Most TVs with ATSC (aka over the air/antenna tuners) also support clear QAM.
There are many, many more SD digital channels available as well, but this list is intended to index only HD stations. Let me know if I’ve missed any or if the logical mappings change.