Mortgaged Properties

Exhibit 10.1b

AMENDMENT NO. 1 AND AGREEMENT dated as of February 29, 2004 (this “Amendment”), with respect to the Credit Agreement dated as of February 10, 2004 (the “Credit Agreement”), among Atlantic Broadband Finance, LLC, a Delaware limited liability company (“Borrower”), Atlantic Broadband Holdings I, LLC (“Holdings”), the Subsidiary Guarantors listed on the signature pages thereto, the several lenders from time to time party thereto (the “Lenders”), Merrill Lynch & Co., Merrill Lynch, Pierce, Fenner & Smith Incorporated as Sole Lead Arranger and Book Runner (in such capacity, the “Arranger”), Merrill Lynch, Pierce, Fenner & Smith Incorporated and General Electric Capital Corporation as Co-Syndication Agents (in such capacity, the “Co-Syndication Agents”), General Electric Capital Corporation as Documentation Agent (in such capacity the “Documentation Agent”), Credit Lyonnais New York Branch as Agent and Société Générale as Administrative Agent for the Lenders (in such capacity, the “Administrative Agent”).

A. Pursuant to the Credit Agreement, the Lenders have agreed to extend credit to the Borrower pursuant to the terms and conditions set forth therein.

B. The Credit Parties have requested that the Arranger, Administrative Agent and Required Lenders agree to amend certain provisions of the Credit Agreement as set forth herein.

C. The Arranger, Administrative Agent and Required Lenders are willing to so agree and to amend the Credit Agreement pursuant to the terms and subject to the conditions set forth herein.

D. Capitalized terms used and not otherwise defined herein shall have the meanings ascribed to them in the Credit Agreement.

In consideration of the premises and the agreements, provisions and covenants contained herein, the parties hereto hereby agree, on the terms and subject to the conditions set forth herein, as follows:

SECTION 1. Amendment to subsection 6.01(g). Subsection 6.1(g) is hereby amended by deleting the phrase “identified on Schedule 6.1(a).”

SECTION 2. Amendment to subsection 6.1(h). Subsection 6.1(h) is hereby amended by inserting, in front of the words “The Administrative Agent shall have,” on the first line thereof, “Except with respect to the Real Properties listed on Schedule 7.10,”

SECTION 3. Amendment to subsection 6.1(i). Subsection 6.1(i) is hereby amended by (a) deleting clause (ii) thereof in its entirety and replacing it with “except with respect to Real Properties listed on Schedule 7.10, an opinion of such other local counsel in Florida, Maryland, New York, Pennsylvania and West Virginia in the form of Exhibit L-2 or otherwise in form and substance reasonably satisfactory to the Administrative Agent and the Arranger and,” (b) inserting the word “and” before clause (vi) and (c) deleting the “and (vii) a Survey with respect to such Mortgaged Property.” at the end of such subsection.

SECTION 4. Amendment to subsection 7.10. Subsection 7.10 is hereby amended by deleting it in its entirety and replacing it with:

“Post-Closing Collateral Matters. (a) Within 30 days after the Closing Date, the applicable Credit Parties shall obtain and deliver to the Administrative Agent (to the extent such items have not been provided as of the Closing Date) with respect to each of the Real Properties listed on Schedule 7.10, the following:

(i) a duly executed and acknowledged Mortgage, together with such certificates, affidavits, questionnaires, instruments or returns and financing statements meeting the requirements of subsections 6.1(h)(i) and 6.1(h)(ii);

(ii) policies or certificates of insurance as required by subsection 6.1(h)(iii);

(iii) evidence reasonably acceptable to the Administrative Agent of payment of all applicable mortgage recording taxes, fees, charges, costs and expenses required for the recording of such Mortgage;

(iv) a Title Policy;

(v) such consents, approvals, estoppels, tenant subordination agreements or other instruments as required by subsection 6.1(h)(vi); and

(vi) an opinion of local counsel in the state in which the applicable Real Property is located in the form of Exhibit L-2 or otherwise in form and substance reasonably satisfactory to the Administrative Agent and the Arranger.

(b) Within 60 days after the Closing Date, the applicable Credit Parties shall obtain and deliver to the Administrative Agent a Survey with respect to each of the Mortgaged Properties. Upon obtaining said Survey, the applicable Credit Party shall cause to be delivered endorsements to the Title Policy delivered pursuant to subsection 7.10(a)(iv) above, removing the customary survey exceptions therein, providing the comprehensive and survey endorsements thereto as well as any other endorsements set forth in subsection 6.1(h)(v) which were omitted as a result of the applicable Credit Parties failure to obtain a Survey contemporaneously with said Title Policy, within ten (10) Business Days after the delivery of said Survey.

(c) Within 45 days after the Closing Date, the applicable Credit Parties shall use commercially reasonable efforts to obtain a subordination, non-disturbance and attornment agreement for each of the leaseholds of the applicable Credit Parties located at 162 Forman Landing Lane, Wye Mills, MD 21679 and 1960 Normandy Drive, Miami Beach, FL from all mortgagees or beneficiaries, as applicable, of the fee interest of such properties, on the Administrative Agent’s standard form or such other form reasonably satisfactory to the Administrative Agent.

(d) To the extent that any legal description contained in any leasehold Mortgages delivered to the Administrative Agent on or about the Closing Date prove incorrect (as indicated in any Survey, title commitment or title update subsequently provided), the applicable

Credit Parties shall cooperate, at their own cost and expense, in the amendment of any legal description to any such leasehold Mortgage or title insurance policy in respect thereof.

(e) Within 60 days after the Closing Date, the applicable Credit Party shall cause the Title Policy delivered as of the Closing Date with respect to the Real Property located at 120 Southmont Boulevard, Johnstown, PA to be amended to add to the insured property thereunder the legal description of parcel 1 contained in Exhibit A to the Mortgage (“Parcel 1”) encumbering such Real Property (the “Southmont Boulevard Mortgage”) executed and delivered to the Administrative Agent as of the Closing Date, and in connection therewith, the applicable Credit Party shall cause (i) a Title Policy (or an amendment to such existing Title Policy with respect to he Southmont Boulevard Mortgage) to be issued in favor of the Administrative Agent with respect to Parcel 1 and (ii) cause all of the other conditions set forth in subsection 7.10(a) and 7.10(b) to be satisfied with respect Parcel 1. In the event that the legal description contained in the Southmont Boulevard Mortgage is incorrect based on the title commitment to be issued within 60 days after the Closing Date with respect thereto, the applicable Credit Party shall cooperate with the Administrative Agent, at the Credit Party’s sole cost and expense, to amend the Southmont Boulevard Mortgage to correct such legal description.

SECTION 5. Amendment to Schedules.

(a) Schedule 5.13 is hereby amended by deleting it in its entirety and replacing it with Annex A attached hereto.

(b) Schedule 5.23 is hereby amended by deleting the references to Great Valley, Little Valley Town, Little Valley Village, Salamanca City and Salamanca Town, each in the State of New York.

(c) Schedule 7.10 is hereby amended by deleting it in its entirety and replacing it with Annex B attached hereto.

SECTION 6. Credit Agreement. Except as specifically provided hereby, the Credit Agreement shall continue in full force and effect in accordance with the provisions thereof as in existence on the date hereof. After the date hereof, any reference to the Credit Agreement in any Credit Document shall mean the Credit Agreement as modified hereby. This Amendment shall be a Credit Document for all purposes.

SECTION 7. Applicable Law. This Amendment shall be governed by, and be construed in accordance with, the laws of the State of New York.

SECTION 8. Counterparts. This Amendment may be executed in two or more counterparts, each of which shall constitute an original but all of which when taken together shall constitute one contract. Delivery of an executed signature page of this Amendment by facsimile transmission shall be effective as delivery of a manually executed counterpart hereof.

SECTION 9. Headings. The Section headings used herein are for convenience of reference only, are not part of this Amendment and are not to affect the construction of, or to be taken into consideration in interpreting, this Amendment.

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed by their respective authorized officers as of the day and year first written above.

Annex A

Schedule 5.13 - Fee Properties, Leased Properties, Other Properties and

Mortgaged Properties

Annex B

Schedule 7.10 - Post Closing Collateral Matters

1. Bunny Hop Road, Claysburg, PA 16625

2. 80 Forest Edge Lane, Lewiston, PA 17044

3. 1 Stoney Acres Road, Mifflinburg, PA 17844

4. 2 Fernwood Drive, Bradford, PA 16701

5. 1278 South Fork Road, Moorefield, WV 26836

6. Old Pittsburgh Road, Uniontown, PA 15401