There are a few ways to find out which cities have cable-modem access:

1. Ask your cable company - cable companies have coverage maps that show which areas have access to cable-modem internet. You can ask your cable company customer service to provide you with this information.

2. Check online - there are websites and resources that provide information on which cities have cable-modem access. Some of these include BroadbandNow, CableTV.com, and HighSpeedInternet.com.

3. Use a search engine - you can also use search engines such as Google or Bing to search for "cable-modem internet in (your city or area)" to see if there are any providers who offer this service.

4. Check with local government - some cities or municipalities have contracts with cable companies to provide internet access in their area. You can contact your local government or visit their website to find out if cable-modem internet is available in your area.