<PAGE>   1
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                       SECURITIES AND EXCHANGE COMMISSION

                              WASHINGTON, DC 20549

                                   FORM 10-QSB
                   QUARTERLY REPORT UNDER SECTION 13 OR 15 (D)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                 FOR THE QUARTERLY PERIOD ENDED: MARCH 31, 1998
                         COMMISSION FILE NUMBER 0-15885

                           NATIONAL DATACOMPUTER, INC.
                 (Name of Small Business Issuer in its Charter)

          DELAWARE                                             04-2942832
(State or other jurisdiction of                              (IRS Employer
 incorporation or organization)                             Identification #)
                                                  

900 Middlesex Turnpike, Bldg. 5
Billerica, Ma.                                                    01821
(Address of principal executive offices)                        (Zip Code)

         Registrant's telephone number including area code (978)663-7677

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

Check whether the issuer (1) filed all reports required to be filed by section
13 or 15 (d) of the Securities and Exchange Act of 1934 during the past 12
months (or for such shorter period that the registrant was required to file such
report(s), and (2) has been subject to such filing requirements for the past
ninety (90) days.

                         Yes___X_____     No_________

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of March 31, 1998.

COMMON STOCK, $0.08 PAR VALUE                              1,628,342
   (Title of each class)                                (number of shares)


<PAGE>   2



                           NATIONAL DATACOMPUTER, INC.
                                      INDEX
                          PART I. FINANCIAL INFORMATION

                                                                  Page No.
ITEM 1.  FINANCIAL STATEMENTS:

         Balance Sheet as of
         March 31, 1998 (unaudited) and December 31,1997...............3

         Statement of Operations
         for the three months ended
         March 31, 1998 and March 30, 1997 (unaudited).................4

         Statement of Changes in
         Stockholders' Equity for the three
         months ended March 31, 1998 (unaudited).......................5

         Statement of Cash Flows
         for the three months ended
         March 31, 1998 and March 30, 1997 (unaudited).................6

         Notes to Financial Statements.................................7


ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITIONS
          AND RESULTS OF OPERATIONS....................................9

                           PART II. OTHER INFORMATION

ITEM 1.  Legal Proceedings............................................11

ITEM 2.  Changes in Securities........................................11

ITEM 3.  Defaults upon Senior Securities..............................11

ITEM 4.  Submissions of Matters to a Vote of Security Holders.........11

ITEM 5.  Other Information............................................11

ITEM 6.  Exhibits and Reports on Form 8 - K...........................11

SIGNATURES............................................................12



<PAGE>   3
<TABLE>
<CAPTION>

NATIONAL DATACOMPUTER, INC.
BALANCE SHEET
------------------------------------------------------------------------------------------------------------------------------




                                                                                              March 31,          December 31,
                                                                                                 1998                1997
                                                                                             (Unaudited)
<S>                                                                                        <C>                 <C>           
Assets
Current Assets:

    Cash and cash equivalents                                                              $      650,152      $      208,731
    Accounts receivable, net of allowance for doubtful accounts                                   983,093           1,545,319
    Inventories                                                                                 1,576,734           1,298,979
    Other current assets                                                                           76,196              59,800
                                                                                           ---------------     ---------------

       Total current assets                                                                     3,286,175           3,112,829

Fixed assets, net                                                                                 230,799             259,512
                                                                                           ---------------     ---------------

                                                                                           $    3,516,974      $    3,372,341
                                                                                           ===============     ===============

Liabilities and stockholders' equity
Current Liabilities:
    Convertible debt to related party                                                      $      175,000      $       75,000
    Current obligations under capital lease                                                        29,749              41,810
    Accounts payable                                                                              358,836             349,807
    Accrued payroll and related taxes                                                             122,269             127,675
    Accrued expenses - other                                                                      228,760             264,024
    Accrued interest on preferred stock                                                           205,500             102,750
    Deferred revenues, current portion                                                            609,163             470,125
    Deferred compensation                                                                          39,205              45,214
                                                                                           ---------------     ---------------

       Total current liabilities                                                                1,768,482           1,476,405

Convertible debt to related party                                                                       -             158,730
Obligations under capital lease                                                                    70,617              70,617
Deferred revenues                                                                                  38,143              38,143
                                                                                           ---------------     ---------------

                                                                                                1,877,242           1,743,895
                                                                                           ---------------     ---------------



Stockholders' equity
    Preferred stock, Series A convertible, $0.001 par value; 20 shares
       authorized; 0 shares issued and outstanding at March 31, 1998 and December 31, 1997              -                   -

    Preferred stock, Series B convertible $0.001 par value; 4,200 shares
       authorized, issued and outstanding (liquidating preference of $4,200,000)                3,685,206           3,685,206

    Preferred stock, Series C convertible $0.001 par value; 900 shares
       authorized, issued and outstanding (liquidating preference of $900,000)                    834,370             808,412

    Preferred stock, Series D convertible $0.001 par value; 350 shares
       authorized, issued and outstanding (liquidating preference $350,000)                       324,639             303,995

    Preferred stock, Series E convertible $0.001 par value; 500 shares
       authorized; 500 and 0 shares issued and outstanding at March 31, 1998 and
       December 31, 1997, respectively (liquidating preference of $500,000)                       273,880                   -

    Common stock, $0.08 par value; 5,000,000 shares authorized; 1,628,342 and 1,628,332
       shares issued and outstanding at March 31, 1998 and December 31, 1997, respectively        130,268             130,267

    Capital in excess of par value                                                             10,478,158          10,310,761
    Accumulated deficit                                                                       (13,650,347)        (13,165,753)
    Unamortized stock compensation                                                                (85,173)            (93,173)
    Notes receivable - employees                                                                 (351,269)           (351,269)
                                                                                             -------------       -------------

       Total stockholders' equity                                                               1,639,732           1,628,446
                                                                                           ---------------     ---------------

                                                                                           $    3,516,974      $    3,372,341
                                                                                           ===============     ===============

</TABLE>


                  The accompanying notes are an integral part
                         of these financial statements.

      

                                     Page 3

<PAGE>   4
<TABLE>
<CAPTION>

NATIONAL DATACOMPUTER, INC.
STATEMENT OF OPERATIONS
----------------------------------------------------------------------------------------------------------------

                                                                        First Fiscal Quarter Ended


                                                                 March 31, 1998               March 30, 1997
                                                                   (Unaudited)                 (Unaudited)
<S>                                                         <C>                          <C>    
Revenues        
       Net product revenue                                  $              471,141       $            1,243,464
       Service and other revenue                                           430,612                      291,974
                                                            -----------------------      -----------------------

                                                                           901,753                    1,535,438

Cost of sales and services                                                 574,262                      821,625
                                                            -----------------------      -----------------------

                                                                           327,491                      713,813
                                                            -----------------------      -----------------------

Operating expenses:
       Research and development                                            206,021                      377,290
       Selling, general and administrative                                 477,622                      631,105
                                                            -----------------------      -----------------------

                                                                           683,643                    1,008,395
                                                            -----------------------      -----------------------

Loss from operations                                                      (356,152)                    (294,582)

Other income (expense):
       Interest and other income                                                                          1,735
       Interest expense                                                    (25,692)                      (5,481)
                                                            -----------------------      -----------------------

Net loss                                                    $             (381,844)      $             (298,328)
                                                            =======================      =======================

Calculation of net loss per common share and dilutive share equivalent:

       Net loss                                             $             (381,844)      $             (298,328)
       Preferred stock preferences                                        (363,351)                     (96,500)
                                                            -----------------------      -----------------------

Net loss attributable to common stockholders                $             (745,195)      $             (394,828)
                                                            =======================      =======================

Basic and diluted net loss per share                        $                (0.46)      $                (0.32)
                                                            =======================      =======================

Weighted average shares                                                  1,628,332                    1,251,925
                                                            =======================      =======================

</TABLE>



                  The accompanying notes are an integral part
                         of these financial statements.

                                     Page 4

<PAGE>   5
<TABLE>
<CAPTION>

NATIONAL DATACOMPUTER, INC.
STATEMENT OF STOCKHOLDERS' EQUITY
(Unaudited)
-------------------------------------------------------------------------------------------------------------------------------

                                    PREFERRED STOCK SERIES B        PREFERRED STOCK SERIES C        PREFERRED STOCK SERIES D   
                                  ----------------------------    ----------------------------    ---------------------------- 
                                                                                                                               
                                                NET ISSUANCE                    NET ISSUANCE                    NET ISSUANCE   
                                     SHARES        PRICE            SHARES         PRICE             SHARES         PRICE      
     
<S>                                   <C>       <C>                    <C>        <C>                   <C>        <C>         
Balance at December 31, 1997          4,200     $3,685,206             900        $808,412              350        $303,995    

Net loss                                                                                                                       

Issuance of preferred stock                                                                                                    

Interest on preferred stock (Note 7)                                                                                           

Amortization of stock compensation                                                                                             
 
Amortization of discounted
  conversion rate on Preferred
   Stock                                                                            25,958                           20,644    
     
Adjustment for fractional shares                                                                                               


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

Balance at March 31, 1998             4,200     $3,685,206             900        $834,370              350        $324,639    
                                     =======   ============         =======     ===========           =======    ===========   

</TABLE>

<TABLE>
<CAPTION>

NATIONAL DATACOMPUTER, INC.
STATEMENT OF STOCKHOLDERS' EQUITY
(Unaudited)
-------------------------------------------------------------------------------------------------------------------------------

                                           PREFERRED STOCK SERIES E                   COMMON STOCK
                                         ----------------------------    -------------------------------------
                                                                                                    CAPITAL IN         NOTES       
                                                       NET ISSUANCE                       PAR        EXCESS          RECEIVABLE    
                                           SHARES          PRICE          SHARES         VALUE     OF PAR VALUE      EMPLOYEES     
     
<S>                                          <C>                        <C>            <C>          <C>              <C>           
Balance at December 31, 1997                    -                       1,628,332      $130,267     $10,310,761      ($351,269)    

Net loss                                                                                                                           

Issuance of preferred stock                   500          273,880                                      214,000                    

Interest on preferred stock (Note 7)                                                                                               

Amortization of stock compensation                                                                                                 
 
Amortization of discounted
  conversion rate on Preferred
   Stock                                                                                                (46,602)
     
Adjustment for fractional shares                                               10             1              (1)


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

Balance at March 31, 1998                     500         $273,880      1,628,342      $130,268     $10,478,158      ($351,269)    
                                            =======      ===========   ===========    ==========   =============    ============   

</TABLE>

<TABLE>
<CAPTION>

NATIONAL DATACOMPUTER, INC.
STATEMENT OF STOCKHOLDERS' EQUITY
(Unaudited)
-----------------------------------------------------------------------------------------
                                     
                                             UNAMORTIZED                          TOTAL
                                                STOCK         ACCUMULATED     STOCKHOLDERS'
                                             COMPENSATION       DEFICIT          EQUITY
     
<S>                                           <C>             <C>              <C>       
Balance at December 31, 1997                  ($93,173)       ($13,165,753)    $1,628,446

Net loss                                                          (381,844)     ($381,844)

Issuance of preferred stock                                                      $487,880

Interest on preferred stock (Note 7)                              (102,750)     ($102,750)

Amortization of stock compensation               8,000                             $8,000
 
Amortization of discounted
  conversion rate on Preferred
   Stock                                
     
Adjustment for fractional shares        

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

Balance at March 31, 1998                     ($85,173)       ($13,650,347     $1,639,732
                                             ===========     ==============   ============
</TABLE>

 
                  The accompanying notes are an integral part
                         of these financial statements.

                                     Page 5


<PAGE>   6
<TABLE>
<CAPTION>

NATIONAL DATACOMPUTER, INC.
STATEMENT OF CASH FLOWS
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS
---------------------------------------------------------------------------------------------------------------------------

                                                                                 


                                                                                     March 31, 1998        March 30, 1997
                                                                                       (Unaudited)           (Unaudited)


<S>                                                                             <C>                     <C>       
Cash flows from operating activities:
     Net loss                                                                   $         (381,844)     $         (298,328)
     Adjustments to reconcile net loss to net
        cash provided by (used for) operating activities:
        Depreciation and amortization                                                       28,713                  25,622
        Amortization of stock compensation                                                   8,000                   7,799
        Amortization of deferred debt issuance costs
           and debt discount                                                                18,789                       -
        Changes in assets and liabilities:
           (Increase) decrease in accounts receivable                                      562,226                (408,010)
           (Increase) decrease in inventories                                             (277,755)                 26,319
           Increase in other current assets                                                (18,915)                (23,492)
           Increase in accounts payable                                                      9,029                 115,674
           Decrease in accrued expenses
               and deferred compensation                                                   (46,679)               (152,201)
           Increase in deferred revenues                                                   139,038                  47,267
                                                                                  -----------------       -----------------

     Net cash provided by (used for) operating activities                                   40,602                (659,350)
                                                                                  -----------------       -----------------

Cash flows from investing activities:
     Purchases of fixed assets                                                                   -                 (10,242)
                                                                                  -----------------       -----------------

     Net cash used for investing activities                                                      -                 (10,242)
                                                                                  -----------------       -----------------

Cash flows from financing activities:
     Proceeds from issuance of  preferred stock and warrants,
        net of issuance costs                                                              487,880               1,224,583
     Proceeds from issuance of convertible note to related party                                 -                 250,000
     Principal payment on convertible debt                                                 (75,000)                      -
     Principal payments on obligations under capital lease                                 (12,061)                (10,414)
                                                                                  -----------------       -----------------

     Net cash provided by financing activities                                             400,819               1,464,169
                                                                                  -----------------       -----------------

Net increase in cash and cash equivalents                                                  441,421                 794,577
Cash and cash equivalents at beginning of year                                             208,731                 722,285
                                                                                  -----------------       -----------------

Cash and cash equivalents  at end of period                                     $          650,152      $        1,516,862
                                                                                  =================       =================


Supplemental Cash Flow Information:
     Cash paid for interest                                                     $            9,422      $            5,416
     Non-cash investing and financing activities:
        Accrued Interest on preferred stock charged to
           accumulated deficit                                                             102,750                  99,000
        Purchase of property and equipment  under capital lease                                  -                   7,720



                  The accompanying notes are an integral part
                         of these financial statements.

</TABLE>


                                     Page 6



<PAGE>   7

                           NATIONAL DATACOMPUTER, INC.
                          NOTES TO FINANCIAL STATEMENTS
                                   (UNAUDITED)


1.    ORGANIZATION

         National   Datacomputer,    Inc.   (the   "Company")   designs,  
      develops, manufactures,   markets  and  services  a  line  of  hand-held 
      battery  powered microprocessor-based  data  collection  products and  
      computers  and  associated peripherals for use in mobile operations.

2.    SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

      BASIS OF PRESENTATION

         The accompanying unaudited financial statements, which are for interim
      periods, do not include all disclosures provided in the annual financial
      statements. These unaudited financial statements should be read in
      conjunction with the financial statements and the footnotes thereto
      contained in the Annual Report on Form 10-KSB for the year ended December
      31, 1997 of National Datacomputer, Inc., as filed with the Securities and
      Exchange Commission.

      INTERIM PERIODS

         In the opinion of the Company, the accompanying unaudited financial
      statements contain all adjustments (which are of a normal and recurring
      nature) necessary for a fair presentation of the financial statements. The
      results of operations for the three months ended March 31, 1998 are not
      necessarily indicative of the results to be expected for the full year.

      REVENUE RECOGNITION

         The Company recognizes revenues for products upon shipment. Revenue
      from installation and training is recognized upon completion of the
      project. Service revenue is recognized ratably over the contractual
      periods.

      LOSS PER SHARE

         Loss per share is determined by dividing net loss, after deducting
      certain amounts associated with the Company's preferred stock, by the
      weighted average number of common shares outstanding during the year.



                                     Page 7

<PAGE>   8

         Interest payable to preferred stockholders, the fair value of
      inducements to convert preferred stock into common stock, and any discount
      implicit in the conversion terms upon issuance of preferred stock are
      added to the net loss to determine the amount of net loss attributable to
      common stockholders.

      RESEARCH AND DEVELOPMENT AND COMPUTER SOFTWARE DEVELOPMENT COSTS

         Research and development costs, other than software development costs,
      have been charged to operations as incurred. SFAS No. 86, "Accounting for
      the Costs of Computer Software to be Sold, Leased or Otherwise Marketed",
      requires the capitalization of certain computer software development costs
      incurred after technological feasibility is established. No software
      development costs have been capitalized at March 31, 1998 or March 30,
      1997.

<TABLE>
<CAPTION>

3.    INVENTORIES

      Inventories consist of the following:                     MARCH 31,                DECEMBER 31,
                                                                   1998                      1997
                                                          -----------------------    ----------------------

<S>                                                             <C>                        <C>      
      Raw Material                                              $ 756,934                  $ 623,593
      Work-in-process                                             546,510                    450,238
      Finished goods                                              273,290                    225,148
                                                          -----------------------    ----------------------

                               Total                           $1,576,734                 $1,298,979
                                                          =======================    ======================

         Inventories are stated at the lower of cost (first-in, first-out) or market.

</TABLE>



4.    CONVERTIBLE PREFERRED STOCK AND PROMISSORY NOTE

      In March 1998, the Company designated and sold 500 shares of Series E
Convertible Preferred Stock with a warrant to purchase up to 700,000 shares of
common stock at an exercise price of $.75 per share, for net proceeds of
$487,880. The warrant expires in March 2000. The Series E Convertible Preferred
Stock was sold to the same stockholder of the previously issued Series B, Series
C and Series D Convertible Preferred Stock. The proceeds of this financing were
allocated to the preferred shares and warrant based on an estimate of their fair
values. This resulted in $214,000 being ascribed to the warrant which was
recorded as additional paid-in-capital and $273,880 being recorded as preferred
stock. Series E Convertible Preferred Stock has voting rights, dividend
preference, liquidation preference, mandatory conversion and Company redemption
terms similar to the Company's existing Series B, Series C and Series D
Convertible Preferred Stock. The Subscription Agreement for Series E Convertible
Preferred Stock offers anti-dilution protection to its shareholders. Series E
Convertible Preferred Stock is convertible into shares of common stock at a
conversion price of $.75.


                                     Page 8

<PAGE>   9

      The Company, in conjunction with the issuance of the Series E Convertible
Preferred Stock, canceled its previously issued warrants to purchase 700,000
shares of common stock for $4.00 per share. Additionally, the Company changed
the conversion price on the Series B and Series C Convertible Preferred Stock to
$2.74 and offered anti-dilution protection to these shareholders. In addition,
the shareholder of the Series E Convertible Preferred Stock agreed to place into
escrow 2,100 shares of the Series B Convertible Preferred Stock that is also
owned by this shareholder. The Company may at its option and at any time through
January 31, 2000 redeem the escrowed shares of Series B Convertible Preferred
Stock, which has a face value of $1,000 per share, at a price of $1,250 per
share.

      Also in March 1998, the Company refinanced the $250,000 convertible debt
by making a principal payment of $75,000 and issuing a convertible note payable
for $175,000. The note bears interest at a rate of 6% per annum, matures in
March 1999, and is convertible into shares of the Company's common stock at a
conversion price equal to the average closing bid price for the Company's common
stock for the five days ending March 6, 1998. The note can be converted at the
option of the holder after January 1, 1999.

ITEM 2.

MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF 
OPERATIONS.

         The following discussion and analysis should be read in conjunction
with the financial statements and notes thereto appearing elsewhere herein.



RESULTS OF OPERATIONS


         THREE MONTHS ENDED MARCH 31, 1998 COMPARED TO THREE MONTHS ENDED MARCH
30, 1997.

         Total revenues in the first quarter of fiscal year 1998 were $901,753
compared to $1,535,438 in the prior comparable quarter, a decrease of 41%. The
decrease in revenue was attributable to a decrease in sales of units of the
Company's Datacomputers which decreased approximately 62% to $471,141 during the
three months ended March 31, 1998, from $1,243,464 during the prior comparable
quarter.

         Service and other revenues for the current quarter were $430,612
compared to $291,974 for the previous comparable quarter, an increase of 47%.
The Company expects that service and other revenues will continue to rise as a
result of improved maintenance and pricing policies instituted.



                                     Page 9

<PAGE>   10


         Cost of sales and services, as a percentage of net revenues, increased
to 64% during the three months ended March 31, 1998 from 54% during the prior
comparable period. The increase is primarily attributable to a higher percentage
of peripheral sales in the first three months of 1998 which carry a lower
margin.

         Research and development expenses decreased to $206,021 in the first
three months of 1998, from $377,291 for the same period in 1997, a decrease of
approximately 45%. The decrease resulted primarily from a reduction in the
Company's product development staff due to the completion of the new
Datacomputer model DC4 which was introduced in the later part of 1997.

         Selling, general and administrative expenses decreased to $477,622 in
the first three months of 1998 from $631,105 for the same period in 1997, a
decrease of approximately 24%. The lower level of costs resulted primarily from
the Company's ongoing programs of streamlining its operations and organizational
structure.

         The Company's operating loss was $356,152 during the three months ended
March 31, 1998, compared to a loss from operations of $294,582 during the three
months ended March 30, 1997. The increased loss was primarily attributable to
the decrease in the Company's sales.

         Interest expenses was $25,692 in the first three months of 1998,
compared to $5,481 in the first three months of 1997. This increase resulted
primarily from the amortization of approximately $16,000 to interest expense
related to the discount on the convertible debt obtained in 1997.

LIQUIDITY AND CAPITAL RESOURCES

         The Company had a cash balance of $650,152 at March 31, 1998 compared
to $208,731 at December 31, 1997. The increase in cash was due primarily to cash
generated from the sale of 500 shares of Series E Convertible Preferred Stock
with a warrant to purchase up to 700,000 shares of common stock at an exercise
price of $.75 per share, for net proceeds of $487,880.

         The Company also refinanced the $250,000  convertible debt by making a 
principal  payment of $75,000 and issuing a convertible note payable 
for $175,000.

         At March 31, 1998, the Company had cash of $650,152 and a current ratio
of 1.9:1. The Company anticipates that available cash, together with cash flow
from anticipated operations, will be sufficient to meet its working capital
needs for the remainder of 1998. However, unanticipated adverse results of
operations could impact anticipated cash flows and, as a result, there can be no
assurance that the Company will not be required to raise additional capital or
that the Company will be able to raise additional capital on favorable terms, if
at all.

                                    Page 10

<PAGE>   11


                           PART II - OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

         The Company is not presently involved in any material pending
         litigation.

ITEM 2. CHANGES IN SECURITIES

         Not Applicable

ITEM 3. DEFAULTS UPON SENIOR SECURITIES

         Not Applicable

ITEM 4. SUBMISSIONS OF MATTERS TO A VOTE OF SECURITY HOLDERS

         Not Applicable

ITEM 5. OTHER INFORMATION

         Not Applicable

ITEM 6. EXHIBITS AND REPORTS ON FORM 8 - K

         (a)      Exhibits
                  (11)   Statement Re: Computation of Per Share Earnings.
                  (27)   Financial Data Schedule.

         (b)      Form 8-K was filed on January 12, 1998 describing the
                  Company's change in fiscal year from the last Sunday in
                  December to December 31.

         (c)      Form 8-K was filed on February 18, 1998 describing  sales of 
                  equity  securities  pursuant to regulation S.


                                    Page 11



<PAGE>   12



                                   SIGNATURES

Pursuant to the requirements of the Securities and Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                           NATIONAL DATACOMPUTER, INC.


May 13, 1998                               /s/ Malcolm M. Bibby
                                           --------------------------------
                                           Malcolm M. Bibby
                                           President


May 13, 1998                               /s/ Gerald S. Eilberg
                                           --------------------------------
                                           Gerald S. Eilberg
                                           Vice President, Finance and
                                           Administration 
                                           Chief Financial Officer




                                    Page 12