<PAGE>   1

================================================================================


                     SECURITIES AND EXCHANGE COMMISSION
                           WASHINGTON, D.C.  20549

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

                                  FORM 10-Q

/X/ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES 
    EXCHANGE ACT OF 1934.

For the quarterly period ended December 31, 1995

                                   OR

/ / TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
    EXCHANGE ACT OF 1934.

For the transition period from          to
                               --------    --------


                         Commission File No. 0-14805
                                MICROCOM, INC.
            (Exact name of registrant as specified in its charter)

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


               MASSACHUSETTS                           04-2710644
      (State or other jurisdiction of              (I.R.S. Employer
      incorporation or organization)            Identification Number)
      
          500 RIVER RIDGE DRIVE                        02062-5028
          NORWOOD, MASSACHUSETTS                       (Zip Code)
  (Address of principal executive offices)

      REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE: (617) 551-1000

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

       SECURITIES REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT: NONE
         SECURITIES REGISTERED PURSUANT TO SECTION 12(g) OF THE ACT:
                         COMMON STOCK, PAR VALUE $.01
                                    
                  ------------------------------------------

Indicate by check / / whether the registrant (1) has filed all reports     
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.  Yes  X  no    .
                                               ---    ---

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date:  As of December 31, 1995,      
15,431,763.                                                               


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<PAGE>   2


                                MICROCOM, INC.

<TABLE>
                              TABLE OF CONTENTS


<S>                                                                    <C>
PART I.  FINANCIAL INFORMATION

CONSOLIDATED BALANCE SHEETS ......................................      3

CONSOLIDATED STATEMENTS OF OPERATIONS ............................      4

CONSOLIDATED STATEMENTS OF CASH FLOWS ............................      5

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS .......................      6

MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
     AND RESULTS OF OPERATIONS ...................................      7


PART II.  OTHER INFORMATION


EXHIBITS AND REPORTS ON FORM 8-K .................................      9

SIGNATURES .......................................................     10

</TABLE>


                                      2


<PAGE>   3
PART I.  FINANCIAL INFORMATION
<TABLE>


                                                 MICROCOM, INC.

                                           CONSOLIDATED BALANCE SHEETS

                                                 (Unaudited)


<CAPTION>
(In thousands)
                                                                 DECEMBER 31, 1995   MARCH 31, 1995
                                                                 -----------------   --------------
                                 ASSETS
<S>                                                                     <C>             <C>
Current assets:
 Cash and equivalents ............................................      $ 37,825        $   863
 Accounts receivable, less reserves of $327 and $250 at
  December 31, 1995 and March 31, 1995, respectively .............        37,566         22,183
 Inventories .....................................................        23,373         16,248
 Prepaid expenses and other current assets .......................         1,424            822
                                                                        --------        -------
  Total current assets ...........................................       100,188         40,116
Property and equipment, net ......................................         6,983          5,683
Other assets, net ................................................        11,639         11,989
                                                                        --------        -------
                                                                        $118,810        $57,788
                                                                        ========        =======

                  Liabilities AND STOCKHOLDERS' EQUITY

Current liabilities:
 Current portion of capitalized leases and short-term debt .......      $    611        $12,543
 Accounts payable ................................................        14,995          6,923
 Accrued expenses ................................................         3,127          2,918
                                                                        --------        -------
  Total current liabilities ......................................        18,733         22,384
                                                                        --------        -------
Long-term portion of capitalized leases ..........................         2,526            122
                                                                        --------        -------

Stockholders' equity:
 Common stock, $.01 par value, authorized - 30,000 shares,
  issued - 16,413 shares at December 31, 1995, and 12,088 shares
  at March 31, 1995 ..............................................           164            121
 Capital in excess of par value ..................................       115,049         61,190
 Stock loans - related parties ...................................        (2,237)        (1,942)
 Accumulated deficit .............................................       (12,927)       (21,589)
 Treasury stock, at cost, 981 shares .............................        (2,613)        (2,613)
 Cumulative translation adjustment ...............................           115            115
                                                                        --------        -------
  Total stockholders' equity .....................................        97,551         35,282
                                                                        --------        -------
                                                                        $118,810        $57,788
                                                                        ========        =======
</TABLE>

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



                                       3

<PAGE>   4
<TABLE>

                                                     MICROCOM, INC.

                                         CONSOLIDATED STATEMENTS OF OPERATIONS
                           FOR THE THREE AND NINE MONTHS ENDED DECEMBER 31, 1995 AND 1994

                                                      (Unaudited)


<CAPTION>
(In thousands, except per share amounts)
                                                                Three Months Ended         Nine Months Ended
                                                                ------------------         -----------------
                                                                 1995         1994          1995        1994
                                                                 ----         ----          ----        ----

<S>                                                             <C>        <C>           <C>         <C>
Net sales ..................................................    $39,977    $23,134       $101,341    $67,219
Cost of sales ..............................................     23,821     12,770         58,274     37,110
                                                                -------    -------       --------    -------
Gross margin ...............................................     16,156     10,364         43,067     30,109
                                                                -------    -------       --------    -------

Operating expenses:
 Research and development ..................................      4,316      2,725         11,218      7,601
 Sales and marketing .......................................      6,175      4,369         17,411     13,740
 General and administrative ................................      1,750      1,215          4,084      3,509
                                                                -------    -------       --------    -------
  Total operating expenses .................................     12,241      8,309         32,713     24,850
                                                                -------    -------       --------    -------

Income from operations .....................................      3,915      2,055         10,354      5,259
Interest income ............................................        339          3            878         66
Interest and other expenses, net ............................      (185)      (259)        (1,042)      (514)
                                                                -------    -------       --------    -------
Income before income taxes .................................      4,069      1,799         10,190      4,811
Provision for income taxes .................................        610        270          1,528        721
                                                                -------    -------       --------    -------
Net income .................................................    $ 3,459    $ 1,529       $  8,662    $ 4,090
                                                                =======    =======       ========    =======

Net income per share .......................................    $   .21    $   .13       $    .57    $   .34
                                                                =======    =======       ========    =======

Weighted average number of shares outstanding ..............     16,715     11,921         15,196     12,002
                                                                =======    =======       ========    =======

</TABLE>

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




                                       4
<PAGE>   5
<TABLE>

                                                    MICROCOM, INC.

                                       CONSOLIDATED STATEMENTS OF CASH FLOWS
                              FOR THE NINE MONTHS ENDED DECEMBER 31, 1995 AND 1994


                               (Unaudited)

<CAPTION>
(In thousands)
                                                                               1995           1994
                                                                            --------        --------
<S>                                                                        <C>            <C>
Cash flows from operating activities:
 Net income. ..........................................................    $   8,662      $   4,090

Adjustments to reconcile net income to net cash used in
 operating activities:
  Depreciation and amortization .......................................        5,485          4,451
  Changes in assets and liabilities:
   Accounts receivable, net ...........................................      (15,383)        (3,827)
   Inventories ........................................................       (7,125)       (13,276)
   Prepaid expenses and other current assets ..........................         (602)           299
   Accounts payable and accrued expenses ..............................        8,281           (630)
   Accrued restructuring costs ........................................            -         (1,070)
                                                                           ---------      ---------
     Net cash used in operating activities ............................         (682)        (9,963)
                                                                           ---------      ---------

Cash flows used in investing activities:
 Capitalized software development costs and purchased technology ......       (4,408)        (3,230)
 Purchase of property and equipment ...................................       (3,077)        (2,053)
 Other assets .........................................................         (117)           380
                                                                           ---------      ---------
      Net cash used in investing activities ...........................       (7,602)        (4,903)
                                                                           ---------      ---------

Cash flows from financing activities:
 Proceeds from public offering, net ...................................       50,418              -
 (Payments) borrowings under revolving credit line, net ...............      (12,020)         9,920
 Banker acceptance on inventory purchases .............................         (195)          (541)
 Borrowings (payments) on capitalized leases ..........................        2,687           (230)
 Repayment of stock loans .............................................          461              -
 Exercise of stock options and employee stock purchase plan ...........        3,895          1,107
                                                                           ---------      ---------
      Net cash provided by financing activities .......................       45,246         10,256
                                                                           ---------      ---------

Net increase (decrease) in cash and equivalents .......................       36,962         (4,610)
Cash and equivalents at beginning of period ...........................          863          5,342
                                                                           ---------      ---------
Cash and equivalents at end of period .................................    $  37,825      $     732
                                                                           =========      =========

</TABLE>

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




                                       5
<PAGE>   6
                             MICROCOM, INC.

               NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

                               (Unaudited)
(In thousands)


Note 1.  BASIS FOR PRESENTATION

The consolidated balance sheet as of December 31, 1995, and the related
consolidated statements of operations and cash flows for the three and nine 
months ended December 31, 1995, and 1994, are unaudited.  In the opinion of 
management, all adjustments necessary for the fair presentation of such 
financial statements have been included, such adjustments consisted only of 
normal recurring items.  Interim results are not necessarily indicative of 
results for a full year.

The financial statements are presented as permitted by Form 10-Q and do not 
contain certain information included in the Company's annual consolidated 
financial statements.

<TABLE>

Note 2.  INVENTORIES
<CAPTION>

                                DECEMBER 31, 1995    MARCH 31, 1995
                                -----------------    --------------
<S>                                  <C>                <C>
Raw materials ...............        $  3,482           $  4,557
Finished goods ..............          19,891             11,691
                                     --------           --------
                                     $ 23,373           $ 16,248
                                     ========           ========

</TABLE>


<TABLE>

Note 3.  PROPERTY AND EQUIPMENT
<CAPTION>
                                                                                           Depreciable Life
                                                  DECEMBER 31, 1995    MARCH 31, 1995          in Years
                                                  -----------------    --------------      ----------------
<S>                                                     <C>               <C>                <C>
Computer equipment and software ..............          $ 9,890           $  9,503                2-7
Manufacturing equipment ......................            3,062              2,937                3-7
Furniture and fixtures .......................            1,629              1,458                  8
Leasehold improvements .......................            2,295              1,830           Life of Lease
                                                        -------           --------
                                                         16,876             15,728
Accumulated depreciation and amortization ....           (9,893)           (10,045)
                                                        -------           --------
                                                        $ 6,983           $  5,683
                                                        =======           ========
</TABLE>

                                       6
<PAGE>   7
         MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
                          AND RESULTS OF OPERATIONS


RESULTS OF OPERATIONS 

Net Sales - Net sales for the three and nine month periods ended
December 31, 1995, were $39,977,000 and $101,341,000, respectively, a 73% and
51% increase from the same periods in fiscal 1995.  These increases were
primarily attributable to increased sales of remote site V.34 modem products
and central site remote network access products, particularly the High Density
Management Systems (HDMS).  International sales for the three and nine month
periods ended December 31, 1995, were $24,162,000 and $47,563,000,
respectively, as compared to $7,235,000 and $18,188,000 for the same periods
last year.  International sales for the three and nine month periods ended
December 31, 1995, were 60% and 47%, respectively, of net sales as compared to
31% and 27% for the same periods last year.  The increases in international
sales were primarily due to increased sales of remote site V.34 modem products.
For the three and nine month periods ended December 31, 1995, sales to a
Japanese distributor accounted for 28% and 18% of net sales, respectively.

Gross Margin - Gross margins for the three and nine month periods ended
December 31, 1995, were 40% and 42%, respectively, of net sales, as compared to
45% for each of the same periods last year.  The decreases were primarily due
to unit sales of lower margin products increasing at a higher rate than the
growth of other higher margin products.  In the future, the Company expects
continued pressure on gross margins as a result of higher unit sales of lower
margin products.
        
Research and Development - During the three and nine month periods ended 
December 31, 1995, research and development costs increased $1,591,000 and 
$3,617,000, respectively, or 58% and 48% from the same periods last year. 
These increases reflect the Company's continued investment in new and existing
technologies. The increases were principally due to the hiring of additional
engineering personnel and increased consulting and contract fees. Research and
development costs were 11% of net sales for each of the three and nine months
ended December 31, 1995, as compared to 12% and 11%, respectively, in the
previous fiscal year.
        
Sales and Marketing - In the three and nine month periods ended 
December 31, 1995, sales and marketing expenses increased $1,806,000 and
$3,671,000, respectively, or 41% and 27% from the same periods last year.  The
increases were directly related to the expansion of the Company's international
distribution channels, coupled with additional marketing programs, primarily
advertising, and variable selling expenses from increased net sales.

General and Administrative - During the three and nine month periods ended 
December 31, 1995, general and administrative expenses increased $535,000 and 
$575,000, respectively, or 44% and 16% from the same periods last year. The 
increases were primarily due to increased personnel and operational costs.

Interest Income - In the three and nine month periods ended December 31, 1995 
interest income increased by $336,000 and $812,000, respectively.  These 
increases were primarily due to the investment of the proceeds from the 
Company's public offering of common stock completed on June 28, 1995.

Interest and Other Expenses - During the three and nine month periods ended 
December 31, 1995, interest and other expenses decreased by $74,000 and 
increased by $528,000, respectively.  The increase during the nine month period
ended December 31, 1995 was primarily due to the utilization of the Company's
line of credit during the first three months of the year.  There were no
borrowings under the Company's line of credit at December 31, 1995.

Income Taxes - The Company's effective tax rate was 15% for both periods 
reported.  The difference between the statutory rate and the effective tax rate 
reflects the utilization of a portion of the Company's net operating loss carry 
forwards.  At March 31, 1995, the Company had available $21,509,000 in net 
operating loss carry forwards, which may be used to offset future taxable 
income, and $3,959,000 in research and development credit carry forwards, which 
may be used to offset future taxes payable.  These carry forwards expire 
through 2009 and are subject to review and possible adjustment by the Internal 
Revenue Service.


                                      7
<PAGE>   8
         MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
                          AND RESULTS OF OPERATIONS
                                 (CONTINUED)


LIQUIDITY AND CAPITAL RESOURCES    

On June 28, 1995, the Company completed a public offering of 3,480,000 shares 
of common stock at $15.625 per share.  The proceeds to the Company after
deducting underwriting commissions and other expenses of the offering were
$50,418,000.  Approximately $12,000,000 of the offering proceeds were used to
repay indebtedness under the Company's credit facility.

As of December 31, 1995, the Company had $37,825,000 in cash and equivalents.  
On December 13, 1995, the Company amended its bank revolving credit facility, 
increasing the borrowing amount to $25,000,000 from $16,000,000.  The terms of 
the facility allow the Company to borrow up to an amount (the "Maximum 
Borrowing Amount") equal to the lesser of (i) $25,000,000 or (ii) an amount 
based on the Company's eligible accounts receivable.  The Maximum Borrowing 
Amount is reduced by amounts which may be drawn on outstanding letters of 
credit and bankers' acceptances and by a percentage of the Company's exposure 
under foreign currency exchange contracts.  Interest on borrowings is at the 
banks' prime rate.  At December 31, 1995, the Company was contingently liable 
with respect to $9,030,000 in outstanding letters of credit and its bank credit 
availability was approximately $15,989,000. Under the terms of the credit 
facility, which expires in November 1996, the Company is required to comply 
with certain covenants.  At December 31, 1995, the Company was in compliance 
with all covenants.

Since its inception, the Company has met its liquidity requirements through 
cash provided by operations, product line dispositions, public and private 
stock offerings, lease arrangements for facilities and equipment and short-term 
borrowings from banks.  Management believes that its cash and equivalents, line 
of credit availability, and cash provided by operations will be adequate to 
meet the Company's liquidity requirements for the immediate future.

FOREIGN CURRENCY HEDGING 

To date, all of the Company's transactions (including customer sales and 
purchases from vendors) have been denominated in U.S. dollars, except for an 
immaterial amount of customer sales denominated in U.K. pounds sterling.  The 
Company has hedged the currency risk associated with these foreign sales by
entering into forward contracts.  The gains or losses on such contracts are
deferred until the contracts are settled and are then recognized as other
income or expense.


                                      8
<PAGE>   9
PART II.  OTHER INFORMATION


ITEM 6.   EXHIBITS AND REPORTS ON FORM 8-K

          (a)  EXHIBITS.

                   Exhibit 10.1 - Fourth Amendment to Credit Agreement dated as
                                  of December 13, 1995 between Silicon Valley 
                                  Bank, BayBank, N.A. and the Company.
                   Exhibit 10.2 - Amended promissory note dated as of 
                                  December 13,1995 between Silicon Valley Bank 
                                  and the Company
                   Exhibit 10.3 - Amended promissory note dated as of 
                                  December 13,1995 between Baybank, N.A. and 
                                  the Company
                   Exhibit 11.0 - Calculation of net income per share
                   Exhibit 27.0 - Financial Data Schedule

          (b)  REPORTS ON FORM 8-K.

                   No reports on Form 8-K were filed by the Company during the
                   period covered by this report.





                                      9
<PAGE>   10
                                  SIGNATURES




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


<TABLE>

<S>                                    <C>

DATE:   February 14, 1996              BY:                  /s/  Roland D. Pampel
      --------------------------           ----------------------------------------------------------
                                                          Roland D. Pampel, President,
                                                     Chief Executive Officer and Director




                                    
DATE:   February 14, 1996              BY:                  /s/  Peter J. Minihane
      --------------------------           ----------------------------------------------------------
                                           Peter J. Minihane, Executive Vice President of Operations,
                                                    Chief Financial Officer and Treasurer

</TABLE>




                                      10
<PAGE>   11
                                                            EXHIBIT 10.1


                     LOAN DOCUMENT MODIFICATION AGREEMENT
                    (No. 4; dated as of December 13, 1995)


        LOAN DOCUMENT MODIFICATION AGREEMENT dated as of December 13, 1995 by
and among MICROCOM, INC., a Massachusetts corporation with its principal place
of business at 500 River Ridge Drive, Norwood, Massachusetts 02062 (the
"BORROWER"), SILICON VALLEY BANK as a Lender (in such capacity, "SVB"),
BAYBANK, N.A. as a Lender (in such capacity, "BAYBANK") and Silicon Valley Bank
as agent for SVB and BayBank (in such capacity, the "AGENT").

        1.      Reference to Existing Loan Documents.
                ------------------------------------

        Reference is hereby made to that Credit Agreement dated March 22, 1995
among the Borrower, the Agent and the Lenders as previously amended as of 
April 28, 1995, June 21, 1995 and September 14, 1995 (with the attached 
schedules and exhibits, the "CREDIT AGREEMENT") and the Loan Documents referred
to therein, including without limitation those certain Notes of the Borrower 
dated March 22, 1995, each in the principal amount of $8,000,000 (the "Notes"), 
and the Security Instruments referred to therein.  Unless otherwise defined 
herein, capitalized terms used in this Agreement shall have the same respective
meanings as set forth in the Credit Agreement.

        2.      Effective Date.
                --------------

        This Agreement shall become effective as of December 13, 1995 (the
"EFFECTIVE DATE"), provided that the Agent shall have received the following on
or before December 20, 1995 and provided further, however, in no event shall
this Agreement become effective until signed by an officer of the SVB in
California:

                a.  two copies of this Agreement, duly executed by the Borrower;

                b.  an amended and restated promissory note in the principal
amount of $12,500,000 payable to the order of SVB in the form enclosed herewith
(the "AMENDED SVB NOTE"), duly executed by the Borrower;

                c.  an amended and restated promissory note in the principal
amount of $12,500,000 payable to the order of BayBank in the form enclosed 
herewith (the "AMENDED BAYBANK NOTE" and together with the Amended SVB Note 
the "AMENDED NOTES"), duly executed by the Borrower;

                d.  evidence of the approval by your Board of Directors of this
Agreement and the Amended Notes; and

                e.  evidence of the approval of the attached consent by the 
Board of Directors of Microcom Systems, Inc.

        By the signature of its authorized officer below, the Borrower is
hereby representing that, except as modified in SCHEDULE A attached hereto, 
the representations of the Borrower set forth in the Loan Documents (including
those contained in the Credit Agreement, as amended by this Agreement) are true
and correct as of the Effective Date as if made on and as of such date.  The
Borrower agrees to pay a nonrefundable facility fee in connection herewith in
the aggregate amount of $44,000. In order to effectuate the foregoing, the
Borrower confirms its authorization as to the debiting of its account with the
each Lender in the amount of $22,000 in order to pay each Lender's portion of
the facility fee for the period up to and including the extended Expiry Date. 
Finally, the Borrower (and Microcom Systems, Inc., signing as a guarantor
below) agrees that, as of the Effective Date, it has no defenses against its
obligations to pay any amounts and perform the obligations under the Credit
Agreement and the other Loan Documents.

        3.      Description of Change in Terms.
                ------------------------------

        As of the Effective Date, the Credit Agreement is modified in the
following respects:




                                      11

<PAGE>   12
                a.  Section 1.1 is hereby amending by deleting the date 
"March 22, 1996" appearing in the fifth line thereof and substituting in place
thereof the date "November 5, 1996."

                b.  Section 1.2 is hereby restated in its entirety as follows:

                    "1.2 LINE OF CREDIT COMMITMENT.  The Total Line of Credit
                    Commitment shall be, in the aggregate, $25,000,000; each of
                    the Lenders shall have a respective Line of Credit 
                    Commitment of $12,500,000."

                c.  Section 1.6 is hereby amended by inserting after the words
"Borrowing Base" in the third line of the last paragraph appearing on page 
three of the Credit Agreement the following:

                    "as such Borrowing Base is calculated at the end of any 
                    fiscal quarter (or, in the event that the Borrower incurs 
                    a Net Loss in any fiscal quarter, then as calculated at the 
                    end of any fiscal month)"

                d.  Section 1.7 is hereby amended by: (a) inserting the word 
"and" immediately before clause (iii); deleting the percentage "10%" appearing
in the sixth line thereof and substituting in place thereof the percentage 
"25%"; and (c) deleting clause (iv).

                e.  Section 1.8 is hereby amended by deleting the date 
"March 22, 1996" appearing in the fourth line thereof and substituting the date
"November 5, 1996."

                f.  Section 2.1 (a) is hereby deleted in its entirety and there 
is hereby substituted in place thereof the following:

                    "The Borrower agrees to pay interest on the unpaid
                    principal amount of the Line of Credit Loans for each day
                    from and including the date each such Line of Credit Loan
                    was made to but excluding the date the principal on such
                    line of credit loan is due (whether at maturity, by
                    acceleration or otherwise) at a fluctuating interest rate
                    per annum equal to the Prime Rate, which interest rate
                    shall change when the Prime Rate shall change such interest
                    shall be payable monthly in arrears on the fifth day of
                    each month commencing with the first such date hereafter
                    and when the aggregate unpaid principal amount of the Line
                    of Credit Loans is due (whether at maturity, by
                    acceleration or otherwise)."

                g.  Section 3 is hereby deleted in its entirety and there is
hereby substituted in place thereof the following

                    "Section 3 Guaranty
                    -------------------

                    Payment and performance of all of the Borrower's present or 
                    future obligations to the Agent and the Lenders, the 
                    Issuing Bank, the Accepting Bank and the FX Bank under the 
                    Agreement, the Notes and the other Loan Documents the
                    "SECURED OBLIGATIONS" shall be secured by that certain
                    guaranty of even date herewith (as amended, modified,
                    supplemented or restated, the ("Guaranty") issued by
                    Microcom Systems, Inc., a Delaware corporation (the
                    "GUARANTOR"), a copy of which is attached hereto as 
                    EXHIBIT F."

                h.  Section 6.4 is hereby amended by deleting the words "one
hundred (100) days" appearing in the first line thereof and substituting the 
words "ninety (90) days."

                i.  Section 6.8 is hereby restated in its entirety as follows:

                    "6.8 INSPECTION.  The Borrower will, upon the request of 
                    the Agent, permit a representative of the Agent (including 
                    any field examiner or auditor retained by the Agent) to 
                    inspect and make copies of the Borrower's books and records 
                    and to conduct a receivables audit, at the expense of the 
                    Borrower, provided, however, as long as no Events of 
                    Default has occurred is continuing only one such audit 
                    shall be conducted in a fiscal year with the aggregate cost 
                    not to exceed $2,500 in any fiscal year."

                j.  Sections 7.11 through 7.14 of the Credit Agreement are 
                    amended in their entirety to read as follows:


                                      12

<PAGE>   13
                        7.11 QUICK RATIO.  The Borrowers will not permit the
                        Quick Ratio at the end of any fiscal quarter, commencing
                        with the quarter ending December 31, 1995, to be less 
                        than 2.0 to 1.

                        7.12 MINIMUM PROFITABILITY.  The Borrower will not
                        permit Net Income at the end of any fiscal quarter, 
                        commencing with the fiscal quarter ending 
                        December 31, 1995, to be less than $1.00.

                        7.13 LEVERAGE.  The Borrower will not permit the ratio 
                        of Total Senior Liabilities to Tangible Net Worth at 
                        the end of any fiscal quarter, commencing with the 
                        fiscal quarter ending December 31, 1995, to exceed 0.5 
                        to 1.

                        7.14 TANGIBLE NET WORTH.  The Borrower will not permit 
                        Tangible Net Worth at the end of any fiscal quarter, 
                        commencing with the fiscal quarter ending
                        December 31, 1995, to be less than the sum of (a)
                        $80,000,000; and (b) fifty percent (50%) of cumulative
                        Net Income for the period taken as a single period)
                        from January 1, 1996 to the end of the fiscal period in
                        question, with no offset for Net Losses.

                k.  Section 7.15 of the Credit Agreement is hereby deleted in 
                    its entirety.

                l.  Section 10 is hereby amended by deleting the following
definitions: "Applicable Inventory Amount," "Applicable Margin," "Eligible 
Inventory," "Inventory Component," "Inventory Dollar Cap, " Inventory Margin," 
"Security Agreement," Security" and "Security Instruments."

                m.  The definition of "Eligible Domestic Accounts Receivable"
under Section 10 is hereby amended by restating in its entirety the proviso at 
the end of subparagraph (i) as follows:

                    "PROVIDED, HOWEVER, that, notwithstanding the foregoing but 
                    solely in the case of Sprint and all its Affiliates and 
                    such other account debtors approved in writing from time to
                    time by all the Lenders in their sole discretion, the
                    maximum aggregate percentage shall be 40% instead of 25%.

                n.  The Compliance and Borrowing Base Certificates attached to 
the Credit Agreement as EXHIBIT C and EXHIBIT D respectively are hereby 
restated in their entirety in the form of EXHIBIT C and EXHIBIT D here for 
respectively.

                o.  The Credit Agreement and the other Loan Documents are hereby
amended wherever necessary or appropriate to reflect the foregoing changes.

        4.      The Agent and the Lenders agree with the Borrower that from and
after the Effective Date the following Security Instruments shall be of no
further force and effect: (a) the Security Agreement of the Borrower (b) the
Collateral Assignment of Patents and Trademarks of the Guarantor; (c) the
Assignment for Security (Patents) of the Guarantor; and (d) Assignment for
Security (Trademarks).  The Agent agrees to executed and caused to be filed
with the appropriate filing authorities the UCC financing statement and other
appropriate documentation to confirm termination of the security interests
granted by the foregoing documents.

        5.      Continuing Validity.
                -------------------

        Upon the effectiveness hereof, each reference in each Loan Document to
"the Credit Agreement", "thereunder", "thereof", "therein", or words of like
import referring to the Credit Agreement, shall mean and be a reference to the
Credit Agreement, as amended hereby.  Except as specifically set forth above,
the Credit Agreement shall remain in full force and effect and is hereby
ratified and confirmed. Except as set forth in Section 4 above,  Each of the
other Loan Documents is in full force and effect and is hereby ratified and
confirmed.  The amendments set forth above (i) do not constitute a waiver or
modification of any term, condition or covenant of the Credit Agreement or any
other Loan Document, other than as expressly set forth herein, and (ii) shall
not prejudice any rights which the Bank may now or hereafter have under or in
connection with the Credit Agreement, as modified hereby, or the other Loan
Documents and shall not obligate the Bank to assent to any further
modifications.

        6.      Miscellaneous.
                -------------




                                      13
<PAGE>   14

                a.  This Agreement may be signed in one or more counterparts 
each of which taken together shall constitute one and the same document.

                b.  THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE COMMONWEALTH OF MASSACHUSETTS.

                c.  THE BORROWER ACCEPTS FOR ITSELF AND IN CONNECTION WITH ITS
PROPERTIES, UNCONDITIONALLY, THE NON-EXCLUSIVE JURISDICTION OF ANY STATE OR 
FEDERAL COURT OF COMPETENT JURISDICTION IN THE COMMONWEALTH OF MASSACHUSETTS IN 
ANY ACTION, SUIT, OR PROCEEDING OF ANY KIND AGAINST IT WHICH ARISES OUT OF OR 
BY REASON OF THIS LOAN MODIFICATION AGREEMENT; PROVIDED, HOWEVER, THAT IF FOR 
ANY REASON SVB CANNOT AVAIL ITSELF OF THE COURTS OF THE COMMONWEALTH OF 
MASSACHUSETTS, THEN VENUE SHALL LIE IN SANTA CLARA COUNTY, CALIFORNIA.

                d.  The Borrower agrees to promptly pay on demand all costs and
expenses of the Agent and the Lenders in connection with the preparation, 
reproduction, execution and delivery of this letter amendment and the other 
instruments and documents to be delivered hereunder, including the reasonable 
fees and out-of-pocket expenses of Sullivan & Worcester, special counsel for 
the Agent and the Lenders with respect thereto.





                                      14
<PAGE>   15
        IN WITNESS WHEREOF, the Agent, the Lenders and the Borrower have caused
this Agreement to be signed under seal by their respective duly authorized
officers as of the date set forth above.


                              SILICON VALLEY EAST, a Division
                              of Silicon Valley Bank, as a Lender
                              and the Agent


                              By:
                                  ------------------------------
                              Name: James C. Maynard
                              Title:   Vice President


                              SILICON VALLEY BANK, as a Lender
                              and the Agent


                              By:
                                  ------------------------------
                              Name:
                              Title:
                              (signed in Santa Clara, CA)


                              BAYBANK, as a Lender


                              By:
                                  ------------------------------
                              Name:
                              Title:

                              MICROCOM, INC.


                              By:
                                  ------------------------------
                              Name:
                              Title:










                                      15

<PAGE>   16
                                  Schedule A
                                  ----------
                                    
        Qualifications and Supplements to Disclosure
        --------------------------------------------

                [If none, state "None"]











                                      16
<PAGE>   17
                                   CONSENT
                                    
        The undersigned, as Guarantor under the guaranty dated as of 
March 22, 1995 (the "GUARANTY") in favor of Silicon Valley Bank as agent for 
Silicon Valley Bank and BayBank, as Lenders, hereby consents to the foregoing 
Loan Document Modification Agreement (No.8, dated December 13, 1995) and hereby
confirms and agrees that the Guaranty is, and shall continue to be, in full
force and effect and is hereby ratified and confirmed in all respects, except
that, upon the Effective date of said Loan Document Modification Agreement,
each occurrence in the Guaranty and in each other Loan Document (as defined in
the Amended and Restated Credit Agreement dated as of March 22, 1995) to which
the undersigned is a party, including , without limitation, any security
agreement or collateral assignment, of "the Credit Agreement," "thereunder,"
"thereof," "therein," or words of like import referring to the Amended and
Restated Credit Agreement, shall mean and be a reference to the Amended and
Restated Credit Agreement, as amended hereby.

                                   MICROCOM SYSTEMS, INC.



                                   By:
                                      ---------------------------------
                                   Name:
                                   Title:



                                   Date:     December 13, 1995






                                      17