I just looked up QAM in Wikipedia and here is what they said
QAM-based HD programming of local stations is sometimes available to analog cable subscribers, without paying the additional fees for a digital cable box. The availability of QAM HD programming is rarely described or publicized in cable company product literature. If cable providers provide rebroadcasts of locally aired programming, they must also carry rebroadcasts of high-definition digital locally aired programming, in an unencrypted form, that does not require the customer to use leased equipment, per FCC Sec. 76.630 and CFR Title 47, §76.901(a). These usually include the local affiliates for CBS, NBC, ABC, PBS, and FOX, and the cable providers comply by rebroadcasting them over QAM channels. The law does not require the cable provider to advertise their availability, and the cable customer service representatives are known to unequivocally (and incorrectly) insist to customers that a converter box is mandatory to view any HD channels.
I just checked the manual for my HP set and it has a QAM tuner. Looks like I will be calling TW tonight.