Several readers contacted me about keeping their free local high-definition channels by using separate inputs for their TV and digital-to-analog converter box.

Mitch Groff of Lancaster e-mailed to say most people who have the smaller DTA boxes are not able to configure the boxes in the manner I mentioned two weeks ago. The DTA boxes Comcast gave out free to customers who subscribe to its Expanded Basic service plan have just one coaxial input and output. He said bigger boxes — not given out for free by Comcast — have more inputs and can do what I mentioned easily.

Also, unless your TV has two coaxial inputs (most don't), you won't be able to set up the DTA box as a separate input. To solve this problem, Mitch suggested getting a coaxial A/B switch.

Comcast will give customers up to two A/B switches free, along with installation instructions. The switch, on an HD-ready TV, allows you to flip positions between Comcast's cable feed and a QAM tuner to get local over-the-air HD channels.

I read on a message board that Comcast scrambled the signal for QAM tuners, but that's not true. The cable provider cannot scramble a local broadcast signal. In fact, Comcast has nothing to do with the local over-the-air signals.

Two weeks ago, I also talked about Comcast HD channels being listed in both the 200s and 800s, with newer HD offerings in the 800s. Why the duplication? A Comcast spokesperson told me it was to get viewers used to channels in the 800s, which is where all HD in this area will be shown in the future. The duplicates are "virtual" channels and do not take up any extra bandwidth on the system.

Last week, Comcast added 10 new HD offerings. There will be 33 more coming by early June.

WGAL-TV traffic alert: Former WGAL-TV 8 morning traffic reporter Rosa Duarte and her family moved to the Washington, D.C. area.

ESPN in 3D: Comcast and ESPN agreed recently to provide ESPN 3D to Comcast digital customers. The channel premiers Friday, June 11, with the 2010 FIFA World Cup soccer tournament.

You will need a 3D-capable television and 3D glasses. According to a USA Today story, you may need a new set-top box to watch 3D, and it's unclear if you'll have to pay a premium.

ESPN will have a second production crew and different announcers for a 3D telecast, because locations for cameras at a regular high-definition sporting event don't necessarily translate to a 3D broadcast, USA Today said.

Fans rejoice: "Three Sheets," the show about alcoholic beverages, hasn't been picked up (the Travel Channel is considering it), but host Zane Lamprey has a new show on HDNet called "Drinking Made Easy." The 24-episode season begins airing in September.

Cut list: NBC has put the medical drama "Mercy" out of its misery, according to the Hollywood Reporter. The network also pulled the plug on its other first-year medical drama, "Trauma."

NBC execs canceled the show once already this season, then ordered a few additional episodes when it was clear "The Jay Leno Show" wasn't going to last. "Law & Order" also was axed, ending a 20-year run on NBC.

Also cut: ABC canceled the following shows: "Romantically Challenged," "Better Off Ted," "Scrubs" (finally) and "FlashForward." Fox canceled "The Wanda Sykes Show."