<PAGE>   1
     As filed with the Securities and Exchange Commission on March 17, 1998
                                                           Registration No. 333-
================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                          APPLIED DIGITAL ACCESS, INC.
             (Exact name of registrant as specified in its charter)

                  DELAWARE                           68-0132939
       (State or other jurisdiction       (IRS Employer Identification No.)
     of incorporation or organization)

                 9855 SCRANTON ROAD, SAN DIEGO, CALIFORNIA 92121
               (Address of principal executive offices) (Zip Code)


                              AMENDED AND RESTATED
                      1996 NON-QUALIFIED STOCK OPTION PLAN
                            (Full title of the plans)

                                 Peter P. Savage
                      President and Chief Executive Officer
                          APPLIED DIGITAL ACCESS, INC.
                9855 SCRANTON ROAD, SAN DIEGO, CALIFORNIA 92121
                    (Name and address of agent for service)
                                 (619) 623-2200
          (Telephone number, including area code, of agent for service)


This Registration Statement shall become effective immediately upon filing with
the Securities and Exchange Commission, and sales of the registered securities
will thereafter be effected upon option exercises or share issuances effected
under the Amended and Restated 1996 Non-Qualified Stock Option Plan.


                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                                     Proposed       Proposed
            Title of                                  Maximum        Maximum
           Securities                  Amount        Offering      Aggregate      Amount of
              to be                    to be           Price        Offering     Registration
           Registered                Registered      per Share       Price           Fee
           ----------                ----------      ---------     ---------     ------------
<S>                               <C>                <C>          <C>            <C>
Common Stock (under Amended and
Restated 1996 Non-Qualified
Stock Option Plan)..............  550,000 shares(1)  $8.31(2)     $4,570,500        $1,180
</TABLE>

-----------------------------
(1) This Registration Statement shall also cover any additional shares of Common
    Stock which become issuable under the Amended and Restated 1996
    Non-Qualified Stock Option Plan by reason of any stock dividend, stock
    split, recapitalization or other similar transaction effected without the
    receipt of consideration which results in an increase in the number of the
    Company's outstanding shares of Common Stock.
(2) Estimated solely for the purpose of computing the amount of the registration
    fee under Rules 457(h) and 457(c) of the Securities Act of 1933, as amended.



<PAGE>   2
                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference

     Applied Digital Access, Inc. (the "Company") hereby incorporates by
reference into this Registration Statement the following documents previously
filed with the Securities and Exchange Commission (the "Commission"):

     (a)  The Company's Annual Report on Form 10-K for the year ended December
          31, 1996.

     (b)  The Company's Quarterly Report on Form 10-Q for the period ended March
          31, 1997.

     (c)  The Company's Quarterly Report on Form 10-Q for the period ended June
          30, 1997.

     (d)  The Company's Quarterly Report on Form 10-Q for the period ended
          September 30, 1997.

     (e)  The Company's Reports on Form 8-K and Form 8-K/A, filed on December
          23, 1997 and January 12, 1998, respectively, as File No. 0-23698.

     (f)  The Form 8-A filed by the Company on March 28, 1994 with the
          Commission as Registration No. 0-23698 (and all amendments thereto),
          in which there is described the terms, rights and provisions
          applicable to the Company's outstanding Common Stock.

     All reports and other documents subsequently filed by the Company pursuant
to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 (the
"1934 Act") prior to the filing of a post-effective amendment which indicates
that all securities offered hereby have been sold or which deregisters all
securities then remaining unsold, shall be deemed to be incorporated by
reference into this Registration Statement and to be a part hereof from the date
of filing of such documents.


Item 4.  Description of Securities

     Not applicable.


Item 5.  Interests of Named Experts and Counsel

     Not applicable.


Item 6.  Indemnification of Directors and Officers

     Section 145 of the Delaware General Corporation Law permits indemnification
of officers and directors of the Company under certain conditions and subject to
certain limitations. Section 145 of the Delaware General Corporation Law also
provides that a corporation has the power to purchase and maintain insurance on
behalf of its officers and directors against any liability asserted against such
person and incurred by him or her in such capacity, or arising out of his or her
status as such, whether or not the corporation would have the power to indemnify
him or her against such liability under the provisions of Section 145 of the
Delaware General Corporation Law.

     Article VII, Section 1 of the Bylaws of the Company provides that the
Company shall indemnify its directors and executive officers to the fullest
extent not prohibited by the Delaware General Corporation Law. The rights to
indemnity thereunder continue as to a person who has ceased to be a director,
officer, employee or agent and inure to the benefit of the heirs, executors and
administrators of the person. In addition, expenses incurred by a director or
executive officer in defending any civil, criminal, administrative or
investigative action, suit or proceeding by reason of the fact that he or she is
or was a director or officer of the Company (or was serving at the Company's
request as a director or officer of another corporation) shall be paid by the
Company in advance of the final disposition of such action, suit or proceeding
upon receipt of an undertaking by or on behalf of such director or officer to
repay such amount if it shall ultimately be determined that he or she is not
entitled to be indemnified by the Company as authorized by the relevant section
of the Delaware General Corporation Law.



                                     II-1.
<PAGE>   3
     As permitted by Section 102(b)(7) of the Delaware General Corporation Law,
Article V, Section (A) of the Company's Certificate of Incorporation provides
that a director of the Company shall not be personally liable for monetary
damages for breach of fiduciary duty as a director, except for liability (i) for
any breach of the director's duty of loyalty to the Company or its stockholders,
(ii) for acts or omissions not in good faith or acts or omissions that involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the Delaware General Corporation Law or (iv) for any transaction from which the
director derived any improper personal benefit.

     The Company has entered into indemnification agreements with each of its
directors and executive officers. Generally, the indemnification agreements
attempt to provide the maximum protection permitted by Delaware law as it may be
amended from time to time. Moreover, the indemnification agreements provide for
certain additional indemnification. Under such additional indemnification
provisions, however, an individual will not receive indemnification for
judgments, settlements or expenses if he or she is found liable to the Company
(except to the extent the court determines he or she is fairly and reasonably
entitled to indemnity for expenses), for settlements not approved by the Company
or for settlements and expenses if the settlement is not approved by the court.
The indemnification agreements provide for the Company to advance to the
individual any and all reasonable expenses (including legal fees and expenses)
incurred in investigating or defending any such action, suit or proceeding. In
order to receive an advance of expenses, the individual must submit to the
Company copies of invoices presented to him or her for such expenses. Also, the
individual must repay such advances upon a final judicial decision that he or
she is not entitled to indemnification.

     The Company has purchased directors' and officers' liability insurance. The
Company intends to enter into additional indemnification agreements with each of
its directors and executive officers to effectuate these indemnity provisions.



Item 7.  Exemption from Registration Claimed

     Not Applicable.

Item 8.  Exhibits

          Exhibit
           Number   Exhibit
          -------   -------

             4.1    Certificate of Incorporation*
             4.2    Bylaws*
               5    Opinion and Consent of Company Counsel, Gray Cary Ware &
                    Freidenrich L.L.P.
            23.1    Consent of Company Counsel is contained in Exhibit 5.
            23.2    Consent of Independent Accountants, Coopers & Lybrand L.L.P.
              24    Power of Attorney. Reference is made to page II-5 of this
                    Registration Statement.
            99.1    Amended and Restated 1996 Non-qualified Stock Option Plan
            99.2    Form of Stock Option Agreement

     *    Filed as an Exhibit to the Company's Report on Form 8-K filed on
          December 23, 1997 (File No. 000-23698) and incorporated herein by
          reference.


Item 9.  Undertakings

     1. The undersigned registrant hereby undertakes:

          (a) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement:

          (i) To include any prospectus required by Section 10(a)(3) of the
     Securities Act of 1933, as amended (the "1933 Act");

          (ii) To reflect in the prospectus any facts or events arising after
     the effective date of this registration statement (or the most recent
     post-effective amendment thereof) which, individually or in the aggregate,
     represent 



                                     II-2.
<PAGE>   4
     a fundamental change in the information set forth in this registration
     statement; and

          (iii) To include any material information with respect to the plan of
     distribution not previously disclosed in this registration statement or any
     material change to such information in this registration statement;

provided, however, that paragraphs (a)(i) and (a)(ii) shall not apply if the
information required to be in a post-effective amendment by those paragraphs is
contained in periodic reports filed by the Company pursuant to Section 13 or
Section 15(d) of the 1934 Act that are incorporated by reference into this
registration statement.

          (b) That, for the purpose of determining any liability under the 1933
Act, each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof; and

          (c) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold upon the termination
of the offering.

     2. The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the 1933 Act, each filing of the Company's
annual report pursuant to Section 13(a) or Section 15(d) of the 1934 Act (and,
where applicable, each filing of an employee benefit plan's annual report
pursuant to Section 15(d) of the 1934 Act) that is incorporated by reference in
this registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

     3. Insofar as indemnification for liabilities arising under the 1933 Act
may be permitted to directors, officers or controlling persons of the Company
pursuant to the foregoing provisions, or otherwise, the Company has been advised
that in the opinion of the Securities and Exchange Commission such
indemnification is against public policy as expressed in the 1933 Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the Company of expenses incurred or
paid by a director, officer or controlling person of the Company in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Company will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the 1933 Act and will be governed by the final
adjudication of such issue.



                                     II-3.
<PAGE>   5
                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8, and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of San Diego, State of California, on this 16th day of
March, 1998.

                                        APPLIED DIGITAL ACCESS, INC.

                                        By /s/ Peter P. Savage
                                          ---------------------------------
                                          Peter P. Savage
                                          President and Chief Executive Officer


                                POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS:

     That the undersigned officers and directors of Applied Digital Access,
Inc., a Delaware corporation, do hereby constitute and appoint Peter P. Savage
and James L. Keefe, and each of them, the lawful attorneys-in-fact and agents
with full power and authority to do any and all acts and things and to execute
any and all instruments which said attorneys and agents, and either one of them,
determine may be necessary or advisable or required to enable said corporation
to comply with the Securities Act of 1933, as amended, and any rules or
regulations or requirements of the Securities and Exchange Commission in
connection with this Registration Statement. Without limiting the generality of
the foregoing power and authority, the powers granted include the power and
authority to sign the names of the undersigned officers and directors in the
capacities indicated below to this Registration Statement, to any and all
amendments, both pre-effective and post-effective, and supplements to this
Registration Statement, and to any and all instruments or documents filed as
part of or in conjunction with this Registration Statement or amendments or
supplements thereof, and each of the undersigned hereby ratifies and confirms
that all said attorneys and agents, or either of them, shall do or cause to be
done by virtue hereof. This Power of Attorney may be signed in several
counterparts.

     IN WITNESS WHEREOF, each of the undersigned has executed this Power of
Attorney as of the date indicated.

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the dates indicated.

<TABLE>
<CAPTION>
Signature                                            Title                          Date
---------                                            -----                          ----
<S>                                 <C>                                        <C> 
/s/ Peter P. Savage                  President and Chief Executive Officer     March 16, 1998
------------------------------          and Director (Principal Executive
Peter P. Savage                                    Officer)

/s/ James L. Keefe                        Vice President, Finance and          March 16, 1998
------------------------------      Administration, Chief Financial Officer
James L. Keefe                        (Principal Financial and Accounting
                                                   Officer)

/s/ Christopher B. Paisley                         Director                    March 16, 1998
------------------------------
Christopher B. Paisley

/s/ Edward F. Tuck                                 Director                    March 16, 1998
------------------------------
Edward F. Tuck

/s/ Kenneth E. Olsen                               Director                    March 16, 1998
------------------------------
Kenneth E. Olsen
</TABLE>



                                     II-4.
<PAGE>   6
                       SECURITIES AND EXCHANGE COMMISSION

                                WASHINGTON, D.C.



                                    EXHIBITS

                                       TO

                                    FORM S-8

                                      UNDER

                             SECURITIES ACT OF 1933


                          APPLIED DIGITAL ACCESS, INC.



<PAGE>   7
                                  EXHIBIT INDEX


    Exhibit
    Number        Exhibit
    ------        -------

      4.1         Certificate of Incorporation*
      4.2         Bylaws*
        5         Opinion and Consent of Company Counsel, Gray Cary Ware &
                  Freidenrich L.L.P.
     23.1         Consent of Company Counsel is contained in Exhibit 5.
     23.2         Consent of Independent Accountants, Coopers & Lybrand L.L.P.
       24         Power of Attorney. Reference is made to page II-5 of this
                  Registration Statement.
     99.1         Amended and Restated 1996 Non-Qualified Stock Option Plan
     99.2         Form of Stock Option Agreement

     *    Filed as an Exhibit to the Company's Report on Form 8-K filed on
          December 23, 1997 (File No. 000-23698) and incorporated herein by
          reference.
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 19060}]
{"company-data": {"conformed-name": "APPLIED DIGITAL ACCESS INC", "cik": "0000919048", "assigned-sic": "3825", "irs-number": "680132939", "state-of-incorporation": "CA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-48105", "film-number": "98567521"}, "business-address": {"street1": "9855 SCRANTON RD", "city": "SAN DIEGO", "state": "CA", "zip": "92121", "phone": "6196232200"}}
1
     As filed with the Securities and Exchange Commission on March 17, 1998
                                                           Registration No. 333-
================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                          APPLIED DIGITAL ACCESS, INC.
             (Exact name of registrant as specified in its charter)

                  DELAWARE                           68-0132939
       (State or other jurisdiction       (IRS Employer Identification No.)
     of incorporation or organization)

                 9855 SCRANTON ROAD, SAN DIEGO, CALIFORNIA 92121
               (Address of principal executive offices) (Zip Code)

                              AMENDED AND RESTATED
                      1996 NON-QUALIFIED STOCK OPTION PLAN
                            (Full title of the plans)

                                 Peter P. Savage
                      President and Chief Executive Officer
                          APPLIED DIGITAL ACCESS, INC.
                9855 SCRANTON ROAD, SAN DIEGO, CALIFORNIA 92121
                    (Name and address of agent for service)
                                 (619) 623-2200
          (Telephone number, including area code, of agent for service)

This Registration Statement shall become effective immediately upon filing with
the Securities and Exchange Commission, and sales of the registered securities
will thereafter be effected upon option exercises or share issuances effected
under the Amended and Restated 1996 Non-Qualified Stock Option Plan.

                         CALCULATION OF REGISTRATION FEE
Proposed       Proposed
            Title of                                  Maximum        Maximum
           Securities                  Amount        Offering      Aggregate      Amount of
              to be                    to be           Price        Offering     Registration
           Registered                Registered      per Share       Price           Fee
           ----------                ----------      ---------     ---------     ------------
Common Stock (under Amended and
Restated 1996 Non-Qualified
Stock Option Plan)..............  550,000 shares(1)  $8.31(2)     $4,570,500        $1,180
-----------------------------
(1) This Registration Statement shall also cover any additional shares of Common
    Stock which become issuable under the Amended and Restated 1996
    Non-Qualified Stock Option Plan by reason of any stock dividend, stock
    split, recapitalization or other similar transaction effected without the
    receipt of consideration which results in an increase in the number of the
    Company's outstanding shares of Common Stock.
(2) Estimated solely for the purpose of computing the amount of the registration
    fee under Rules 457(h) and 457(c) of the Securities Act of 1933, as amended.
2
                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference

     Applied Digital Access, Inc. (the "Company") hereby incorporates by
reference into this Registration Statement the following documents previously
filed with the Securities and Exchange Commission (the "Commission"):

     (a)  The Company's Annual Report on Form 10-K for the year ended December
          31, 1996.

     (b)  The Company's Quarterly Report on Form 10-Q for the period ended March
          31, 1997.

     (c)  The Company's Quarterly Report on Form 10-Q for the period ended June
          30, 1997.

     (d)  The Company's Quarterly Report on Form 10-Q for the period ended
          September 30, 1997.

     (e)  The Company's Reports on Form 8-K and Form 8-K/A, filed on December
          23, 1997 and January 12, 1998, respectively, as File No. 0-23698.

     (f)  The Form 8-A filed by the Company on March 28, 1994 with the
          Commission as Registration No. 0-23698 (and all amendments thereto),
          in which there is described the terms, rights and provisions
          applicable to the Company's outstanding Common Stock.

     All reports and other documents subsequently filed by the Company pursuant
to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 (the
"1934 Act") prior to the filing of a post-effective amendment which indicates
that all securities offered hereby have been sold or which deregisters all
securities then remaining unsold, shall be deemed to be incorporated by
reference into this Registration Statement and to be a part hereof from the date
of filing of such documents.

Item 4.  Description of Securities

     Not applicable.

Item 5.  Interests of Named Experts and Counsel

     Not applicable.

Item 6.  Indemnification of Directors and Officers

     Section 145 of the Delaware General Corporation Law permits indemnification
of officers and directors of the Company under certain conditions and subject to
certain limitations. Section 145 of the Delaware General Corporation Law also
provides that a corporation has the power to purchase and maintain insurance on
behalf of its officers and directors against any liability asserted against such
person and incurred by him or her in such capacity, or arising out of his or her
status as such, whether or not the corporation would have the power to indemnify
him or her against such liability under the provisions of Section 145 of the
Delaware General Corporation Law.

     Article VII, Section 1 of the Bylaws of the Company provides that the
Company shall indemnify its directors and executive officers to the fullest
extent not prohibited by the Delaware General Corporation Law. The rights to
indemnity thereunder continue as to a person who has ceased to be a director,
officer, employee or agent and inure to the benefit of the heirs, executors and
administrators of the person. In addition, expenses incurred by a director or
executive officer in defending any civil, criminal, administrative or
investigative action, suit or proceeding by reason of the fact that he or she is
or was a director or officer of the Company (or was serving at the Company's
request as a director or officer of another corporation) shall be paid by the
Company in advance of the final disposition of such action, suit or proceeding
upon receipt of an undertaking by or on behalf of such director or officer to
repay such amount if it shall ultimately be determined that he or she is not
entitled to be indemnified by the Company as authorized by the relevant section
of the Delaware General Corporation Law.

                                     II-1.
3
     As permitted by Section 102(b)(7) of the Delaware General Corporation Law,
Article V, Section (A) of the Company's Certificate of Incorporation provides
that a director of the Company shall not be personally liable for monetary
damages for breach of fiduciary duty as a director, except for liability (i) for
any breach of the director's duty of loyalty to the Company or its stockholders,
(ii) for acts or omissions not in good faith or acts or omissions that involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the Delaware General Corporation Law or (iv) for any transaction from which the
director derived any improper personal benefit.

     The Company has entered into indemnification agreements with each of its
directors and executive officers. Generally, the indemnification agreements
attempt to provide the maximum protection permitted by Delaware law as it may be
amended from time to time. Moreover, the indemnification agreements provide for
certain additional indemnification. Under such additional indemnification
provisions, however, an individual will not receive indemnification for
judgments, settlements or expenses if he or she is found liable to the Company
(except to the extent the court determines he or she is fairly and reasonably
entitled to indemnity for expenses), for settlements not approved by the Company
or for settlements and expenses if the settlement is not approved by the court.
The indemnification agreements provide for the Company to advance to the
individual any and all reasonable expenses (including legal fees and expenses)
incurred in investigating or defending any such action, suit or proceeding. In
order to receive an advance of expenses, the individual must submit to the
Company copies of invoices presented to him or her for such expenses. Also, the
individual must repay such advances upon a final judicial decision that he or
she is not entitled to indemnification.

     The Company has purchased directors' and officers' liability insurance. The
Company intends to enter into additional indemnification agreements with each of
its directors and executive officers to effectuate these indemnity provisions.

Item 7.  Exemption from Registration Claimed

     Not Applicable.

Item 8.  Exhibits

          Exhibit
           Number   Exhibit
          -------   -------

             4.1    Certificate of Incorporation*
             4.2    Bylaws*
               5    Opinion and Consent of Company Counsel, Gray Cary Ware &
                    Freidenrich L.L.P.
            23.1    Consent of Company Counsel is contained in Exhibit 5.
            23.2    Consent of Independent Accountants, Coopers & Lybrand L.L.P.
              24    Power of Attorney. Reference is made to page II-5 of this
                    Registration Statement.
            99.1    Amended and Restated 1996 Non-qualified Stock Option Plan
            99.2    Form of Stock Option Agreement

     *    Filed as an Exhibit to the Company's Report on Form 8-K filed on
          December 23, 1997 (File No. 000-23698) and incorporated herein by
          reference.

Item 9.  Undertakings

     1. The undersigned registrant hereby undertakes:

          (a) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement:

          (i) To include any prospectus required by Section 10(a)(3) of the
     Securities Act of 1933, as amended (the "1933 Act");

          (ii) To reflect in the prospectus any facts or events arising after
     the effective date of this registration statement (or the most recent
     post-effective amendment thereof) which, individually or in the aggregate,
     represent 

                                     II-2.
4
     a fundamental change in the information set forth in this registration
     statement; and

          (iii) To include any material information with respect to the plan of
     distribution not previously disclosed in this registration statement or any
     material change to such information in this registration statement;

provided, however, that paragraphs (a)(i) and (a)(ii) shall not apply if the
information required to be in a post-effective amendment by those paragraphs is
contained in periodic reports filed by the Company pursuant to Section 13 or
Section 15(d) of the 1934 Act that are incorporated by reference into this
registration statement.

          (b) That, for the purpose of determining any liability under the 1933
Act, each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof; and

          (c) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold upon the termination
of the offering.

     2. The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the 1933 Act, each filing of the Company's
annual report pursuant to Section 13(a) or Section 15(d) of the 1934 Act (and,
where applicable, each filing of an employee benefit plan's annual report
pursuant to Section 15(d) of the 1934 Act) that is incorporated by reference in
this registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

     3. Insofar as indemnification for liabilities arising under the 1933 Act
may be permitted to directors, officers or controlling persons of the Company
pursuant to the foregoing provisions, or otherwise, the Company has been advised
that in the opinion of the Securities and Exchange Commission such
indemnification is against public policy as expressed in the 1933 Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the Company of expenses incurred or
paid by a director, officer or controlling person of the Company in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Company will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the 1933 Act and will be governed by the final
adjudication of such issue.

                                     II-3.
5
                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8, and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of San Diego, State of California, on this 16th day of
March, 1998.

                                        APPLIED DIGITAL ACCESS, INC.

                                        By /s/ Peter P. Savage
                                          ---------------------------------
                                          Peter P. Savage
                                          President and Chief Executive Officer

                                POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS:

     That the undersigned officers and directors of Applied Digital Access,
Inc., a Delaware corporation, do hereby constitute and appoint Peter P. Savage
and James L. Keefe, and each of them, the lawful attorneys-in-fact and agents
with full power and authority to do any and all acts and things and to execute
any and all instruments which said attorneys and agents, and either one of them,
determine may be necessary or advisable or required to enable said corporation
to comply with the Securities Act of 1933, as amended, and any rules or
regulations or requirements of the Securities and Exchange Commission in
connection with this Registration Statement. Without limiting the generality of
the foregoing power and authority, the powers granted include the power and
authority to sign the names of the undersigned officers and directors in the
capacities indicated below to this Registration Statement, to any and all
amendments, both pre-effective and post-effective, and supplements to this
Registration Statement, and to any and all instruments or documents filed as
part of or in conjunction with this Registration Statement or amendments or
supplements thereof, and each of the undersigned hereby ratifies and confirms
that all said attorneys and agents, or either of them, shall do or cause to be
done by virtue hereof. This Power of Attorney may be signed in several
counterparts.

     IN WITNESS WHEREOF, each of the undersigned has executed this Power of
Attorney as of the date indicated.

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the dates indicated.
Signature                                            Title                          Date
---------                                            -----                          ----
/s/ Peter P. Savage                  President and Chief Executive Officer     March 16, 1998
------------------------------          and Director (Principal Executive
Peter P. Savage                                    Officer)

/s/ James L. Keefe                        Vice President, Finance and          March 16, 1998
------------------------------      Administration, Chief Financial Officer
James L. Keefe                        (Principal Financial and Accounting
                                                   Officer)

/s/ Christopher B. Paisley                         Director                    March 16, 1998
------------------------------
Christopher B. Paisley

/s/ Edward F. Tuck                                 Director                    March 16, 1998
------------------------------
Edward F. Tuck

/s/ Kenneth E. Olsen                               Director                    March 16, 1998
------------------------------
Kenneth E. Olsen
II-4.
6
                       SECURITIES AND EXCHANGE COMMISSION

                                WASHINGTON, D.C.

                                    EXHIBITS

                                       TO

                                    FORM S-8

                                      UNDER

                             SECURITIES ACT OF 1933

                          APPLIED DIGITAL ACCESS, INC.
7
                                  EXHIBIT INDEX

    Exhibit
    Number        Exhibit
    ------        -------

      4.1         Certificate of Incorporation*
      4.2         Bylaws*
        5         Opinion and Consent of Company Counsel, Gray Cary Ware &
                  Freidenrich L.L.P.
     23.1         Consent of Company Counsel is contained in Exhibit 5.
     23.2         Consent of Independent Accountants, Coopers & Lybrand L.L.P.
       24         Power of Attorney. Reference is made to page II-5 of this
                  Registration Statement.
     99.1         Amended and Restated 1996 Non-Qualified Stock Option Plan
     99.2         Form of Stock Option Agreement

     *    Filed as an Exhibit to the Company's Report on Form 8-K filed on
          December 23, 1997 (File No. 000-23698) and incorporated herein by
          reference.