<PAGE>   1
                                                                  EXHIBIT 10.33

           THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED
         UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED, AND
               MAY NOT BE SOLD, TRANSFERRED, ASSIGNED, PLEDGED, OR
           HYPOTHECATED ABSENT AN EFFECTIVE REGISTRATION THEREOF UNDER
            SUCH ACT OR UNLESS THE COMPANY HAS RECEIVED AN OPINION OF
           COUNSEL, SATISFACTORY TO THE COMPANY AND ITS COUNSEL, THAT
                       SUCH REGISTRATION IS NOT REQUIRED.

          THIS NOTE IS SUBORDINATED AS SET FORTH IN PARAGRAPH 4 HEREIN

                       HAYES MICROCOMPUTER PRODUCTS, INC.

                    CONVERTIBLE SUBORDINATED PROMISSORY NOTE
                                   (ONE-YEAR)


US $500,000                                                   Atlanta, Georgia
                                                              April 16, 1996


         HAYES MICROCOMPUTER PRODUCTS, INC., a Georgia corporation (the
"Company"), having its principal office located at 5835 Peachtree Corners East,
Norcross, Georgia, for value received hereby promises to pay to ROLLING PROFIT
HOLDINGS LIMITED, (the "Holder"), the sum of FIVE HUNDRED THOUSAND US Dollars
(US $500,000), in lawful currency of the United States of America, on the
earlier to occur of (i) April 15, 1997 or if such day is not a business day, on
the next succeeding business day, or (ii) when the unpaid principal amount of
this Note is declared due and payable by the Holder upon the occurrence of an
Event of Default (as hereinafter defined) (such earlier date, the "Maturity
Date").

         This Note is a "Convertible Subordinated Promissory Note" referred to
in and issued in connection with a loan transaction contemplated by Section 10.5
of the Hayes Microcomputer Products, Inc. Shareholders' Agreement dated as of
April 16, 1996 (as amended, modified or supplemented in accordance with the
terms thereof and in effect from time to time, the "Shareholders' Agreement"),
by and among the Company, the Holder, Dennis C. Hayes and the other
Shareholders, as defined therein. In addition to the terms hereof, this Note and
the Holder are subject to certain restrictions, and entitled to certain rights
and privileges, as set forth in the Merger Agreement (as hereinafter defined)
and the Shareholders' Agreement. The principal amount of this Note, together
with the principal amount of one or more other Convertible Subordinated
Promissory Notes, dated the date hereof and substantially identical to this Note
but for the name of the payee, constitute a "Shareholder Loan."




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         Notwithstanding any provisions hereof to the contrary, no payment of
principal hereof shall be made unless and except to the extent that repayment of
principal is also made by the Company in respect of each outstanding Convertible
Subordinated Promissory Note evidencing a portion of the same Shareholder Loan
that is evidenced by this Note, ratably according to the respective original
principal amounts hereof and thereof. Payment of all amounts due under this Note
shall be made by wire transfer to the Holder pursuant to the instructions set
forth below or to such other account maintained with a United States bank as the
Holder may specify to the Company in writing from time to time, referring to
this Note.

         The following is a statement of the rights of the Holder of this Note
and the conditions to which this Note is subject, and to which the Holder, by
acceptance of this Note, agrees:

         1. Definitions. As used in this Note, the following terms have the
following meanings:

                (i) "Company" means Hayes Microcomputer Products, Inc., a
         Georgia corporation ("New Hayes"), the surviving corporation of the
         merger of Financial Sub with and into Hayes Microcomputer Products,
         Inc., a Georgia corporation, and any corporation which shall succeed to
         or assume the obligations of New Hayes under this Note.

               (ii) "Holder" means any person who shall at the time be the
         registered holder of this Note; ROLLING PROFIT HOLDINGS LIMITED is the
         initial Holder.

         2. Interest. Interest shall accrue on the principal amount of this Note
outstanding from time to time and shall be payable on the Maturity Date and upon
repayment or conversion, at a rate per annum equal to 1-5/8% above the interest
rate announced from time to time by Chemical Bank at its principal office in New
York, New York as its "base rate," each change in such rate to be effective with
each change in such "base rate."

         3. Events of Default. If any of the events specified in this Section 3
shall occur (each an "Event of Default") and be continuing, the Holder may, by
written notice to the Company given on a business day, declare the entire
principal hereof to be immediately due and payable and upon such declaration,
the same shall be due and payable:

                (i) The Company or any subsidiary shall (A) commence a voluntary
         case under the federal bankruptcy laws (as now or hereafter in effect),
         (B) file a petition seeking to take advantage of any other laws,
         domestic or foreign, relating to bankruptcy, insolvency,
         reorganization, winding up or composition or adjustment of debts, (C)
         consent to or fail to contest in a timely and appropriate manner any
         petition filed against it in an involuntary case under such bankruptcy
         or other laws, (D) apply for or consent to, or fail to contest in a
         timely and appropriate manner, the appointment of, or the taking of
         possession by, a receiver, custodian, trustee or liquidator of itself
         or of a substantial part of its property, domestic or foreign, (E)
         admit in writing its inability to

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         pay its debts as they become due, (F) make a general assignment for the
         benefit of creditors, or (F) take any corporate action for the purpose
         of authorizing any of the foregoing; or

               (ii) A case or other proceeding shall be commenced against the
         Company or any of its subsidiaries in any court of competent
         jurisdiction seeking (A) relief under the federal bankruptcy laws (as
         now or hereafter in effect) or under any other laws, domestic or
         foreign, relating to bankruptcy, insolvency, reorganization, winding up
         or adjustment of debts, (B) the appointment of a trustee, receiver,
         custodian, liquidator or the like of the Company, any of its
         subsidiaries or of all or any substantial part of the assets, domestic
         or foreign, of the Company or any of its subsidiaries, and such case or
         proceeding shall continue undismissed or unstayed for a period of sixty
         (60) consecutive days, or any order granting the relief requested in
         such case or proceeding against the Company or any of its subsidiaries
         shall be entered; or

              (iii) Any default or "event of default" shall occur under any
         Senior Indebtedness (as hereinafter defined) that gives the holder
         thereof the right to accelerate, and such holder shall have
         accelerated, the obligations of the Company thereunder; or

               (iv) The Company shall fail to perform or observe any material
         term of (A) the Hayes Microcomputer Products, Inc. Agreement and Plan
         of Merger by and among the Company, Dennis C. Hayes, and the Investors
         (as defined therein), dated as of April 12, 1996 (as currently amended
         and as the same may be amended, modified or supplemented from time to
         time in accordance with its terms, the "Merger Agreement"), (B) the
         Warrants (as defined in the Merger Agreement), or (C) the Shareholders'
         Agreement, in each case to be performed or observed by the Company and
         such failure shall continue beyond any applicable grace period.

         4. Subordination. The indebtedness evidenced by this Note is hereby
expressly subordinated in right of payment, to the extent and in the manner set
forth in that certain Debt Subordination Agreement among the Company, The CIT
Group/Credit Finance, Inc., and Rolling Profit Holdings Limited, dated April 16,
1996, to payment in full of the Superior Debt (as defined therein).

            4.1. Subrogation. Notwithstanding the subordination provided for in 
the foregoing provisions of this Section 4, the Holder's right to receive shares
of Series A Preferred Stock of the Company ("Series A Preferred Stock") (and any
cash in lieu of fractional shares) upon conversion of this Note shall be the
Holder's sole remedy following the occurrence of an Event of Default and neither
such right of conversion nor any shares issuable or issued upon exercise of such
right by the Holder shall be exercisable by or payable to or receivable by the
holder of any Senior Indebtedness.

            4.2. Undertaking.  By its acceptance of this Note, the Holder agrees
to execute and deliver such documents as may reasonably be requested from time
to time by the Company

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on its own behalf or on behalf of the holder of any Senior Indebtedness to give
effect to the foregoing provisions of this Section 4.

         5. Prepayment. This Note may be prepaid in whole or in part, without
penalty, at any time prior to its conversion in accordance with Section 6
hereof.

         6. Conversion.

            6.1. Automatic Conversion. At the close of business on the Maturity
Date the entire unpaid principal amount of this Note and any accrued and unpaid
interest thereon shall be automatically converted into shares of Series A
Preferred Stock. The conversion shall be effected in accordance with the formula
attached hereto as Annex 1.

            6.2. Conversion Procedure.

                  6.2.1. Notice of Conversion Pursuant to Section 6.1. If this
            Note is automatically converted, written notice in the form attached
            hereto as Annex 2 shall be delivered to the Holder of this Note at
            the address last shown on the records of the Company for the Holder
            or given by the Holder to the Company for the purpose of notice or,
            if no such address appears or has been given, at the place where the
            principal executive office or residence of the Holder is located,
            notifying the Holder of the conversion to be effected, specifying
            the principal amount of this Note to be converted and the date on
            which such conversion will occur (or has occurred), and calling upon
            the Holder to surrender to the Company, in the manner and at the
            place designated, this Note. As promptly as practicable after the
            automatic conversion of this Note, the Company at its expense will
            issue and deliver to the Holder of this Note a certificate or
            certificates for the number of full shares of Series A Preferred
            Stock issuable upon such conversion.

                  6.2.2. Mechanics and Effect of Conversion. No fractional 
            shares of Series A Preferred Stock shall be issued upon conversion
            of this Note. In lieu of the Company issuing any fractional shares
            to the Holder upon the conversion of this Note, the Company shall
            pay to the Holder the amount of outstanding principal that is not so
            converted, such payment to be in the form of a check payable to the
            Holder. Upon conversion of this Note and payment of any cash in lieu
            of fractional shares, the Company shall be forever released from all
            its obligations and liabilities under this Note.

            6.3. No Impairment. The Company will not avoid or seek to avoid the
observance or performance of any of the terms to be observed or performed
hereunder by the Company, but will at all times in good faith assist in carrying
out all the provisions of this Section 6 and in taking all such action as may be
necessary or appropriate in order to protect the conversion rights of the Holder
of this Note against impairment.


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         7.  Reservation of Stock Issuable Upon Conversion. The Company shall at
all times reserve and keep available out of its authorized but unissued shares
of Series A Preferred Stock solely for the purpose of effecting the conversion
of this Note such number of shares of Series A Preferred Stock (and shares of
Common Stock of the Company ("Common Stock") for issuance on conversion of such
Series A Preferred Stock) as shall from time to time be sufficient to effect the
conversion of this Note; and if at any time the number of authorized but
unissued shares of Series A Preferred Stock (and shares of Common Stock for
issuance on conversion of such Series A Preferred Stock) shall not be sufficient
to effect the conversion of the entire outstanding principal amount of this
Note, in addition to such other remedies as shall be available to the Holder,
the Company will use all reasonable efforts to take such corporate action as
may, in the opinion of its counsel, be necessary to increase its authorized but
unissued shares of Series A Preferred Stock (and shares of Common Stock for
issuance on conversion of such Series A Preferred Stock) to the number of shares
that is sufficient for such purposes.

         8.  Assignment. Subject to the restrictions on transfer described in
Section 10 below, the rights and obligations of the Company and the Holder of
this Note shall be binding upon and benefit the successors, assigns, heirs,
administrators and transferees of the parties. The rights and obligations of the
Company under this Note may not be assigned by the Company without the prior
written consent of the Holder.

         9.  Waiver and Amendment. Any provision of this Note may be amended,
waived or modified only upon the written consent of the Company and the Holder;
PROVIDED, HOWEVER, that the Company hereby waives (i) presentment for payment,
protest and demand, notice of protest, demand and dishonor and nonpayment of
this Note and (ii) the defense of the statute of limitations in any action on
this Note to the extent permitted by law.

         10. Transfer of this Note or Securities Issuable on Conversion Hereof.
With respect to any offer, sale or other disposition of this Note or securities
into which this Note may be converted, the provisions of Section 7 of the
Shareholders' Agreement shall apply, mutatis mutandis, to the same extent as if
this Note and such securities were "Stock" (as defined in the Shareholders'
Agreement). Each Note thus transferred and each certificate representing the
securities thus transferred shall bear a legend as to the applicable
restrictions on transferability in order to ensure compliance with the Act,
unless in the opinion of counsel for the Company such legend is not required in
order to ensure compliance with the Act. The Company may issue stop transfer
instructions to its transfer agent in connection with such restrictions.

         11. Treatment of Note. To the extent permitted by generally accepted
accounting principles, the Company will treat, account and report this Note as
debt and not equity for accounting purposes and with respect to any returns
filed with federal, state or local tax authorities.

         12. Notices. All notices, requests and other communications that any
party is required or elects to give hereunder shall be in writing and shall be
deemed to have been given (a) upon personal delivery thereof, including by
appropriate courier service, five (5) days after delivery

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to the courier or, if earlier, upon delivery against a signed receipt therefor
or (b) upon transmission by facsimile or telecopier, which transmission is
confirmed, in either case addressed to the Company at the address set forth
below, to the Holder at the address set forth on the signature page of this
Note, or to either of them at such other address as such party shall have
notified the other parties hereto, by notice given in conformity with this
Section 12:

                       Hayes Microcomputer Products, Inc.
                       5835 Peachtree Corners East
                       Norcross, Georgia  30092
                       Attention: Mr. Dennis C. Hayes
                       Telecopy: (770) 840-6830

                       with a required copy to:

                       G. Donald Johnson
                       Parker, Johnson, Cook & Dunlevie
                       1275 Peachtree Street, N.E., Suite 700
                       Atlanta, Georgia 30309
                       Telecopy: (404) 888-7490

         13. No Stockholder Rights. Nothing contained in this Note shall be
construed as conferring upon the Holder or any other person the right to vote or
to consent or to receive notice as a stockholder in respect of meetings of
stockholders for the election of directors of the Company or any other matters
or any rights whatsoever as a stockholder of the Company.

         14. Expenses. The Company will pay all costs and expenses incurred by
the Holder in connection with any amendments, waivers or consents (including any
amendment, waiver or consent that is requested but does not become effective) or
the enforcement by the Holder of its rights under or in respect of this Note.
Such costs and expenses include, but are not limited to:

             (a) the reasonable fees, expenses and disbursements of any
         special counsel or reasonably required local counsel in connection with
         any amendments, waivers or consents of this Note and all out-of-pocket
         expenses incurred by the Holder in connection with any such amendments
         or waivers;

             (b) all costs and expenses, including attorneys' fees, incurred in
         enforcing (or determining whether or how to enforce) any rights under
         this Note or in responding to any subpoena or other legal process or
         informal investigative demand issued in connection with this Note, or
         by reason of being a Holder of this Note; and

             (c) all costs and expenses, including attorneys' fees and financial
         advisors' fees, incurred in connection with the insolvency or
         bankruptcy of the Company or any subsidiary or in connection with any
         work-out or restructuring with respect to the Company or any
         subsidiary.

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         The Company will pay, and will save the Holder harmless from, all
claims in respect of any fees, costs or expenses, if any, of brokers and finders
(other than those retained by the Holder).

         15. No Setoff. This Note shall not be subject to any right of setoff,
recoupment, counterclaim or otherwise in respect of any claims by the Company
against the Holder.

         16. Governing Law. This Note shall be governed by and construed in
accordance with the laws of the State of Georgia, excluding that body of law
relating to conflict of laws.

         17. Heading; References. All headings used herein are used for
convenience only and shall not be used to construe or interpret this Note.
Except where otherwise indicated, all references herein to Sections refer to
Sections hereof.







                     [EXECUTION SET FORTH ON FOLLOWING PAGE]



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IN WITNESS WHEREOF, the Company has caused this Note to be issued this 16th day
of April, 1996.

                                      HAYES MICROCOMPUTER PRODUCTS, INC.



                                       By:          /s/ Dennis C. Hayes
                                               --------------------------------
                                       Name:   Dennis C. Hayes
                                       Title:  Chairman



Name of Holder:            ROLLING PROFIT HOLDINGS LIMITED

Address:                   Arion Commercial Centre
                           Third Floor, Room 304
                           2-12 Queen's Road West
                           Hong Kong

Wire instructions:


                                       -8-

<PAGE>   9



                                                                       ANNEX 1
<TABLE>
<CAPTION>
                               Conversion Formula

         <S>               <C>      <C>
         Total Shares      =        Other Shares  x  Holders' %age ownership PLUS Change
                                                     ---------------------------------------
                                                         Others' %age ownership MINUS Change


         New Shares        =        (Total Shares  -  Existing Shares)  x  Loan %age


         where:

         Total Shares      =        Total number of shares outstanding
                                    and held by Holders of Convertible
                                    Subordinated Promissory Notes entitled to
                                    conversion in respect of the Shareholder
                                    Loan of which this Note evidences a part, as
                                    determined immediately after conversion

         Other             =        Aggregate number of shares of Stock (Common
                                    and Preferred)

         Shares                     owned or controlled by all shareholders that
                                    are not Holders of Convertible Subordinated
                                    Promissory Notes entitled to conversion in
                                    respect of the Shareholder Loan of which
                                    this Note evidences a part, as determined
                                    immediately prior to conversion

        Holders'         =          Aggregate ownership of Stock of the Company,
        %age                        expressed as a percentage, by Holders of
        ownership                   Convertible Subordinated Promissory Notes
                                    entitled to conversion in respect of the
                                    Shareholder Loan of which this Note
                                    evidences a part, as determined immediately
                                    prior to conversion 

        Others' %age     =          100% MINUS Holders' %age ownership 
        ownership       

        Change           =          The percentage obtained by (1) dividing the
                                    aggregate principal amount of the
                                    Shareholder Loan that is subject to
                                    conversion (and of which this Note evidences
                                    a part) by $1,000,000, and (2) multiplying
                                    the result by 1.4. 

        New Shares       =          The number of shares of Series A Preferred 
                                    Stock issuable to the Holder of this Note
                                    upon conversion of such Holder's ratable
                                    share of the aggregate Shareholder Loan
                                    amount converted (and used to determine
                                    "Change")



</TABLE>

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<PAGE>   10

<TABLE>
<S>                      <C>        <C>         
        Existing         =          The aggregate number of shares of Stock 
        Shares                      (Common and Preferred) owned by all Holders
                                    of Convertible Subordinated Promissory Notes
                                    entitled to conversion in respect of the
                                    Shareholder Loan of which this Note
                                    evidences a part, as determined immediately
                                    prior to conversion

        Loan %age        =          The result, expressed as a percentage, 
                                    obtained by dividing the principal amount of
                                    this Note entitled to conversion by the
                                    aggregate amount of the Shareholder Loan
                                    entitled to conversion as part of the same
                                    conversion event
</TABLE>




By way of example, if the number of Existing Shares owned by all Holders of
Convertible Subordinated Promissory Notes is 4,900,000 and the Other Shares
owned or controlled by all Shareholders that are not Holders of Convertible
Subordinated Promissory Notes is 5,100,000, and if the aggregate principal
amount of the Shareholder Loan that is subject to conversion is $13,000,000:

then  Total Shares = 5,100,000 x (49.0 + 18.2) / (51.0 - 18.2)
                     = 5,100,000 x 67.2 / 32.8
                     = 10,448,780 shares

After such conversion, Total shares outstanding and held by Holders of
Convertible Subordinated Promissory Notes, as determined immediately after
conversion, would represent

         10,448,780/(10,448,780 + 5,100,000) = 0.672 or 67.2% of all 
outstanding shares in the corporation.





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<PAGE>   11


                                                                       ANNEX 2


TO HAYES MICROCOMPUTER PRODUCTS, INC.

         The undersigned, the Holder of the foregoing Note, hereby surrenders
such Note for conversion into shares of Series A Preferred Stock of HAYES
MICROCOMPUTER PRODUCTS, INC., to the extent of $________________ unpaid
principal amount of such Note, and requests that the certificates for such
shares be issued in the name of, and delivered to, ___________________________,
whose address is: _________________________________________________________, and
who is a "Permitted Transferee" under and as defined in the Shareholders'
Agreement.

Dated:
      -----------------------------


                            ---------------------------------------------------
                            (Signature must conform in all respects to the name
                             of Holder as specified on the face of the Note)




                            ---------------------------------------------------

                            ---------------------------------------------------

                           (Address)



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