<PAGE>
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                AMENDMENT NO. 1
                                       TO
                                    FORM 10-Q
                                 ON FORM 10-Q/A

(Mark One)

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

                  FOR THE QUARTERLY PERIOD ENDED MARCH 31, 2002

                                       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 NUMBER 000-28473

                                 TRUETIME, INC.


           DELAWARE                                     94-3343279
          (STATE OF                                  (I.R.S. EMPLOYER
        INCORPORATION)                              IDENTIFICATION NO.)

                               3750 WESTWIND BLVD.

                          SANTA ROSA, CALIFORNIA 95403

                                 (707) 528-1230

                    (ADDRESS OF PRINCIPLE EXECUTIVE OFFICES)

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



   Indicate by check mark 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 [ ]

   There were 5,950,000 shares of the Registrant's Common Stock outstanding as
of the close of business on May 8, 2002.

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



                                       1
<PAGE>

          The undersigned registrant hereby amends Part I, Item 1 of its
Quarterly Report on Form 10-Q for the quarter ended March 31, 2002 as
set forth below to correct an inadvertent and immaterial error in the
amount of the Total Stockholders' Equity line item included in the
registrant's balance sheet as of March 31, 2002.



                                       2
<PAGE>

                          PART I: FINANCIAL INFORMATION

ITEM 1: FINANCIAL STATEMENTS AND NOTES

                                 TrueTime, Inc.
                                 BALANCE SHEETS
                (in thousands except share and per share amounts)
<Table>
<Caption>

                                                                                 September 30, 2001   March 31, 2002
                                                                                                         (unaudited)
<S>                                                                                     <C>               <C>
ASSETS
        Current assets:
                   Cash and cash equivalents.....................................       $ 7,809           $ 6,854
                   Trade accounts receivable, net of allowance of $49 and $40 ...         3,450             3,216
                   Inventories ..................................................         5,396             4,733
                   Prepaid expenses and other assets ............................           569               638
                   Income taxes receivable ......................................           635               438
                   Deferred income tax...........................................         1,252             1,765
                                                                                        -------           -------
                     Total current assets........................................        19,111            17,644

        Property and equipment, net..............................................         4,094             3,851
        Prepaid expenses, non-current............................................            53                --
        Goodwill, net of accumulated amortization of $266 and $279...............           765               752
                                                                                        -------           -------
                             Total assets........................................       $24,023           $22,247
                                                                                        =======           =======

LIABILITIES AND STOCKHOLDERS' EQUITY
          Current liabilities:
                    Trade accounts payable.......................................       $   724           $   616
                    Accrued expenses.............................................         1,165               948
                    Capital lease, current.......................................           172               179
                    Deferred revenue.............................................           122                84
                    Lease loss accrual...........................................           578               693
                                                                                        -------           -------
                      Total current liabilities..................................         2,761             2,520

          Non-Current liabilities:
                    Deferred income taxes........................................           105                 2
                    Capital lease................................................           512               421
                    Deferred revenue.............................................            66               126
                    Lease loss accrual...........................................           421                98
                                                                                        -------           -------
                      Total liabilities..........................................         3,865             3,167
                                                                                        -------           -------

          Commitments and contingencies

          Stockholders' equity:
                    Preferred stock, $.01 par value, 1,000,000 shares
                    authorized, no shares issued and outstanding.................            --                --
                    Common stock, $.01 par value, 20,000,000 authorized;
                    5,950,000 shares issued and outstanding......................            60                60
                    Additional paid-in capital...................................        12,907            12,912
                    Additional paid-in capital - warrants........................           455               455
                    Retained earnings............................................         6,736             5,653
                                                                                        -------           -------
                      Total stockholders' equity.................................        20,158            19,080
                                                                                        -------           -------
                             Total liabilities and stockholders' equity..........       $24,023           $22,247
                                                                                        =======           =======
</Table>

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



                                       3
<PAGE>

                                 TrueTime, Inc.
                            STATEMENTS OF OPERATIONS
                (in thousands except share and per share amounts)
                                   (unaudited)


<Table>
<Caption>
                                                                       Three months ended              Six months ended
                                                                March 31, 2001   March 31, 2002   March 31, 2001   March 31, 2002
<S>                                                               <C>              <C>             <C>              <C>

Net sales ...................................................     $     4,561      $     4,406     $     9,504      $     8,302

Cost of sales ...............................................           2,440            2,613           4,840            4,910
                                                                  -----------      -----------     -----------      -----------

Gross profit ................................................           2,121            1,793           4,664            3,392

Selling, general and administrative expenses ................           2,088            1,725           3,918            3,263
Research & development ......................................             909              841           1,704            1,706
Acquisition expenses ........................................              --              150              --              150
                                                                  -----------      -----------     -----------      -----------

Loss from operations .........................................           (876)            (923)           (958)          (1,727)

Interest income ..............................................             82               33             190               74

Interest expense..............................................             --               12              --               25
                                                                  -----------      -----------     -----------      -----------

Loss before taxes ............................................           (794)            (902)           (768)          (1,678)

Income taxes .................................................           (318)            (295)           (307)            (595)
                                                                  -----------      -----------     -----------      -----------

Net loss .....................................................    $      (476)     $      (607)    $      (461)     $    (1,083)
                                                                  ===========      ===========     ===========      ===========

Weighted average shares outstanding - Basic ..................      5,950,000        5,950,000       5,950,000        5,950,000

Basic loss per share .........................................         ($0.08)          ($0.10)         ($0.08)          ($0.18)

Diluted loss per share .......................................         ($0.08)          ($0.10)         ($0.08)          ($0.18)
</Table>

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



                                       4




<PAGE>

                                 TrueTime, Inc.
                            STATEMENTS OF CASH FLOWS
                                 (in thousands)
                                   (unaudited)


<Table>
<Caption>
                                                                 Six months ended     Six months ended
                                                                   March 31, 2001      March 31, 2002
<S>                                                                   <C>                <C>
Cash flows from operating activities:
         Net loss...................................................  $   (461)           $ (1,083)
         Adjustments to reconcile net loss to net cash
         provided by (used in) operating activities:
                  Deferred income taxes.............................      (183)               (616)
                  Depreciation and amortization.....................       319                 458
                  Loss (gain) on disposal of property and
                  equipment.........................................         6                  (5)
                  Compensation expense related to options
                  granted...........................................         6                   5
                  Effects of changes in operating assets and
                  liabilities
                        Trade accounts receivables, net.............       649                 234
                        Inventories.................................        93                 663
                        Prepaid expenses and Other assets...........      (382)                (16)
                        Income taxes................................        --                 197
                        Trade accounts payable......................       (62)               (108)
                        Accrued expenses............................       (21)               (217)
                        Lease loss accrual..........................        --                (208)
                        Deferred revenue............................        72                  22
                                                                      --------            --------

         Net cash provided by (used in) operating activities........        36                (674)
                                                                      --------            --------
Cash flows from investing activities:

         Capital expenditures.......................................    (1,578)               (197)
                                                                      --------            --------

            Net cash used in investing activities...................    (1,578)               (197)
                                                                      --------            --------

Cash flows from financing activities:
         Principal payments on capital lease........................        --                 (84)
                                                                      --------            --------

            Net cash used in financing activities...................        --                 (84)
                                                                      --------            --------

Decrease in cash and cash equivalents................................   (1,542)               (955)

Cash and cash equivalents, beginning of period.......................    7,884               7,809
                                                                      --------            --------
Cash and cash equivalents, end of period............................. $  6,342            $  6,854
                                                                      ========            ========
</TABLE>


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



                                       5
<PAGE>

TRUETIME, INC.
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)


1. BASIS OF PRESENTATION

The balance sheet of TrueTime, Inc. at September 30, 2001 has been derived from
the Company's audited financial statements at that date. The balance sheet at
March 31, 2002, the statements of operations for the three months and six months
ended March 31, 2001 and 2002, and the statements of cash flows for the six
months ended March 31, 2001 and 2002 have been prepared by the Company,
unaudited. In the opinion of management, all adjustments consisting of normal
recurring adjustments, necessary to present fairly the financial position,
results of operations and cash flows have been made. The results of operations
for the three months and six months ended March 31, 2001 and 2002 are not
necessarily indicative of the operating results for a full year or for future
operations.

Certain information and footnote disclosures normally included in financial
statements presented in accordance with accounting principles generally accepted
in the United States of America have been omitted. The accompanying financial
statements should be read in conjunction with the financial statements and notes
thereto contained in the Company's Annual Report on Form 10-K for the year ended
September 30, 2001.

Certain prior year amounts have been reclassified to conform to the 2002
financial statement presentation. The reclassifications have no impact on
previously reported 2001 net loss, total cash flows or stockholders' equity.


2. LOSS PER COMMON SHARE

The following table summarizes the calculation of net loss and weighted average
common shares and common equivalent shares outstanding for purposes of the
computation of losses per share:


                                 TrueTime, Inc.
                              LOSS PER COMMON SHARE

<Table>
<Caption>
                                                              Three months                       Six months
                                                      March 31, 2001   March 31, 2002   March 31, 2001   March 31, 2002

<S>                                                     <C>               <C>             <C>              <C>
    Net loss available to common stockholders (in
    thousands).......................................   $    (476)        $    (607)      $    (461)       $  (1,083)
                                                        =========         =========       =========        =========

    Weighted average common shares outstanding.......   5,950,000         5,950,000       5,950,000        5,950,000
    Weighted average common share equivalents
    Outstanding*.....................................         281               250             255               84
                                                        ---------         ---------       ---------        ---------
    Weighted average common shares and common
    share equivalents outstanding....................   5,950,281         5,950,250       5,950,255        5,950,084
                                                        =========         =========       =========        =========

    Basic loss per common share......................   $   (0.08)        $   (0.10)      $   (0.08)       $   (0.18)
                                                        =========         =========       =========        =========

    Diluted loss per common share....................   $   (0.08)        $   (0.10)      $   (0.08)       $   (0.18)
                                                        =========         =========       =========        =========
</Table>

* Due to their anti-dilutive effect, additional warrants and options totaling
1,037,150 and 1,121,400 shares equivalent for the three and six months ended
March 31, 2001 and 2002, respectively, are excluded from the calculation above.



                                       6
<PAGE>

3. INVENTORIES

Inventories consisted of the following (in thousands), net of reserves of $805
at September 30, 2001 and $307 at March 31, 2002:

<Table>
<Caption>
                                           September 30, 2001    March 31, 2002
<S>                                        <C>                   <C>
Finished goods..........................               $  820           $   707
Work in process.........................                  737               594
Raw material............................                3,839             3,432
                                                       ------            ------
                                                       $5,396           $ 4,733
                                                       ======           =======
</Table>

4. RECENT ACCOUNTING PRONOUNCEMENTS

Business Combinations and Goodwill and Other Intangible Assets

On June 29, 2001, the Financial Accounting Standards Board (FASB) announced the
issuance of Statement of Financial Accounting Standards SFAS 142, "Goodwill and
Other Intangible Assets." The Company has goodwill for which amortization has
been recorded against in prior periods. Amortization of goodwill per quarter is
$6,444; amortization of goodwill for the year would be $25,776. Under the
current guidelines, the Company will adopt the provisions of SFAS on October 1,
2002. Currently, the Company is evaluating the impact of adopting SFAS 142.
Goodwill is carried at $752,112, the net book value.

Accounting for the Impairment or Disposal of Long-Lived Assets

On October 3, 2001, the FASB issued SFAS 144, "Accounting for the Impairment or
Disposal of Long-Lived Assets". SFAS 144 is effective for financial statements
issued for fiscal years beginning after December 15, 2001 and interim periods
within those fiscal years. Early application is encouraged.

This statement supercedes:

     -  SFAS 121 - "Accounting for the Impairment of Long-Lived Assets and for
        Long-Lived Assets to be Disposed of"; and

     -  APB 30 - "Reporting the Results of Operations - Reporting the Effects of
        Disposal of a Segment of a Business".


SFAS 144 sets forth that if the expected undiscounted cash flows from an asset
are insufficient to recover its carrying cost and if the carrying cost exceeds
its estimated market value, then an impairment must be recognized.

SFAS 144 also develops one accounting model for long-lived assets that are to be
disposed of by sale, as well as addressing the principal implementation issues.

SFAS 144 requires that long-lived assets that are to be disposed of by sale be
measured at the lower of book value or fair value less cost to sell.
Additionally, SFAS 144 expands the scope of discontinued operations that can be
distinguished from the rest of the entity and will be eliminated from the
ongoing operations of the entity in a disposal transaction.

The Company is in the process of evaluating the effect of SFAS 142 and 144 on
its financial statements. The impact of adopting these standards is not known at
this time.



                                       7
<PAGE>
5. RESTRUCTURING COSTS

In July 2001, the Company adopted a restructuring plan which included the
abandonment and physical move from approximately 34,500 square feet of its
existing leased facility at Westwind Blvd. and as a result the Company recorded
a $998K lease loss accrual on September 30, 2001. The accrual represents costs
recognized pursuant to EITF 94-3, Liability Recognition for Certain Employee
Termination Benefits and Other Costs to Exit an Activity (Including Certain
Costs Incurred in a Restructuring) and SAB 100, Restructuring and Impairment
Charges. The Company committed to a sufficiently detailed plan that identified
significant actions to be taken and the activities that would not be continued
(including the method of disposition and location of such activities). The
expected date of completion of the plan was December 15, 2001; the Company
completed the plan on December 13, 2001. During the three months ended March 31,
2002, leasehold expenses in the amount of $173,382, which were associated with
the abandoned facility space were charged against the lease loss accrual.
Approximately $93,765 and $112,994 of this charge would have been recognized in
cost of goods sold and $79,617 and $93,946 would have been recognized in
operating expenses for the three months and six months ended March 31, 2002,
respectively.

The following table summarizes the activity in the lease loss accrual (in
thousands):

<Table>
<S>                                                                                                 <C>
         Lease loss accrual at September 30, 2001..............................................     $ 998
         Less:
               Lease payments .................................................................       186
               Building utilities, maintenance ................................................        21
                                                                                                    -----
         Lease loss accrual at March 31, 2002..................................................     $ 791
                                                                                                    =====
</Table>

6. ACCOUNTING FOR INCOME TAXES

The difference between the effective tax rate reflected in the total provision
for income taxes and the statutory federal rate of 34% relate primarily to
permanent differences, limitations on state net operating loss carryforwards,
tax credits and other adjustments.

Deferred income taxes under the liability method reflect the net tax effects of
temporary differences between the carrying amounts of assets and liabilities for
financial reporting purposes and the amounts used for income tax purposes.
Significant components of the Company's deferred income tax liabilities and
assets were as follows:

<TABLE>
<CAPTION>

                                                                             (IN '000's)
                                                                             -----------
                                                                       3/31/02       9/30/01
                                                                       -------       -------
<S>                                                                     <C>           <C>
Deferred income tax assets (current liabilities):
  Allowance for doubtful accounts..............................         $   18        $   21
  Accrued product warranty.....................................             15            16
  Inventories..................................................            151           381
  Accrued compensated absences.................................             99           102
  NOL carryforward.............................................          1,369           439
  Lease loss accrual...........................................            339           428
  Other........................................................           (226)         (135)
                                                                        ------        ------
                                                                         1,765         1,252
Deferred income tax liability:
    Other......................................................             (2)         (105)
                                                                        ------        ------
          Net deferred income tax asset........................         $1,763        $1,147
                                                                        ======        ======
</TABLE>



                                       8
<PAGE>

At March 31, 2002, the Company had available net operating loss (NOL)
carryforwards of approximately $3.4 million and $2.6 million for federal and
state income tax purposes, respectively, expiring beginning in 2020 (federal)
and 2010 (state). Under the liability method, a valuation allowance is provided
when it is more likely than not that some portion or all of the deferred tax
assets will not be realized. Realization is dependent on generating sufficient
taxable income prior to expiration of the loss carryforwards or the possibility
of carrying back current Federal losses to prior profitable years, if such
carryback is available under our tax separation agreement with our then parent,
OYO Corporation U.S.A. Although realization is not assured, management believes
it is more likely than not that all of the net deferred tax asset will be
realized. The amount of the net deferred tax asset considered realizable,
however, could be reduced in the near term if estimates of future taxable income
during the carryforward period are reduced, and such reductions could be
material.

7. OTHER EVENTS

On March 27, 2002, the Company publicly announced that it had entered into a
definitive merger agreement with Symmetricom, Inc. ("Symmetricom") pursuant to
which Symmetricom will exchange 2.6 million shares of Symmetricom common stock
and $5 million in cash, subject to certain possible downward adjustments
relating to costs associated with the transaction, for all the outstanding
shares of TrueTime. The Company will become a wholly owned subsidiary of
Symmetricom. The consummation of the merger is subject to customary conditions,
including approval of the stockholders of the Company. The proposed merger will
be a taxable transaction. Fees in the amount of $.15 million related to the
merger were expensed during the three months ended March 31, 2002.



                                       9
<PAGE>

                                   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 hereunto duly authorized.

                                        TRUETIME, INC.


                                        By:      /s/ Elizabeth A. Withers
                                           -------------------------------------
                                                   Elizabeth A. Withers
                                           President and Chief Executive Officer
                                               (Principal Executive Officer)


                                        By:          /s/ John E. Dutil
                                           -------------------------------------
                                                       John E. Dutil
                                                  Chief Financial Officer
                                                 (Principal Financial and
                                                    Accounting Officer)

Date: May 22, 2002



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