<PAGE>
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                       SECURITIES AND EXCHANGE COMMISSION
 
                             WASHINGTON D.C. 20549
                            ------------------------
 
                                 FORM 10-KSB/A1
 
  /X/    ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
         SECURITIES EXCHANGE ACT OF 1934
 
                  FOR THE FISCAL YEAR ENDED DECEMBER 31, 1997
                                       OR
 
  / /    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
         SECURITIES EXCHANGE ACT OF 1934
 
                       COMMISSION FILE NUMBER: 000-22172
                            ------------------------
 
                              MIDISOFT CORPORATION
 
       (Exact name of small business issuer as specified in its charter)
 
<TABLE>
<S>                         <C>
        WASHINGTON               91-1345532
     (State or other          (I.R.S. Employer
     jurisdiction of         Identification No.)
     incorporation or
      organization)
</TABLE>
 
                       1605 NW SAMMAMISH ROAD, SUITE 205,
                           ISSAQUAH, WASHINGTON 98027
                    (Address of principal executive offices)
 
                                 (425) 391-3610
                          (Issuer's telephone number)
 
          Securities registered pursuant to Section 12(b) of the Act:
 
<TABLE>
<CAPTION>
                                                              NAME OF EACH EXCHANGE
              TITLE OF EACH CLASS                              ON WHICH REGISTERED
-----------------------------------------------  -----------------------------------------------
<S>                                              <C>
                     None                                              N/A
</TABLE>
 
          Securities registered pursuant to Section 12(g) of the Act:
                           COMMON STOCK, NO PAR VALUE
                                (Title of Class)
                            ------------------------
 
    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 / /
 
    Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-B is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-KSB or any amendment to
this Form 10-KSB. /X/
 
    Issuer's revenues for its most recent fiscal year were $3,004,224.
 
    Aggregate market value of voting stock held by non-affiliates of the
registrant as of March 2, 1998 was $5,309,218 (based upon the closing sale price
of $0.843 per share on such date). Number of shares of Common Stock outstanding
as of March 2, 1998: 6,298,005 shares.
 
                      DOCUMENTS INCORPORATED BY REFERENCE
 
    Part III is incorporated by reference from the definitive proxy statement to
be filed in connection with the Company's 1998 Annual Meeting of Shareholders.
 
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    (c)  EXHIBITS.  The following exhibits are filed as part of this report:
 
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<CAPTION>
EXHIBIT NO.  DESCRIPTION
-----------  --------------------------------------------------------------------------------------------------
<C>          <S>
 
     3.1.1(a) Articles of Incorporation of the Company as filed on September 23, 1986 with the Secretary of
               State of the State of Washington.
</TABLE>
 
                                       37
<PAGE>
<TABLE>
<CAPTION>
EXHIBIT NO.  DESCRIPTION
-----------  --------------------------------------------------------------------------------------------------
<C>          <S>
     3.1.2(b) Articles of Amendment to Articles of Incorporation of the Company as filed on February 22, 1989
               with the Secretary of State of the State of Washington.
 
     3.1.3(b) Articles of Amendment to Articles of Incorporation of the Company as filed on July 13, 1994 with
               the Secretary of State of the State of Washington.
 
     3.2.1(b) By-laws of the Company.
 
     3.2.2(a) Amended and Restated By-laws of the Company.
 
       4.1(b) Form of specimen certificate for Common Stock of the Company.
 
       4.2(f) Designation of Rights and Preferences of Series A Convertible Preferred Stock.
 
       4.3(f) Designation of Rights and Preferences of Series A Convertible Preferred Stock.
 
       4.5(h) Form of Securities Purchase Agreement dated October 28, 1997
 
       4.6(h) Form of Registration Rights Agreement dated October 28, 1997
 
       4.7(k) Form of Debenture dated October, 28, 1997
 
    10.1.1(b) Employment Agreement, dated December 31, 1991, as further amended on May 5, 1994, by and between
               Raymond Bily and the Company.
 
    10.1.2(b) Employment Agreement, dated March 1, 1991, as further amended on May 5, 1994, by and between
               Ronald E. Risdon and the Company.
 
    10.1.3(b) Employment Agreement, dated May 15, 1991, as further amended on May 5, 1994, by and between Jerry
               W. Schwartz and the Company.
 
    10.1.4(c) Employment Agreement, dated July 19, 1994, by and between Calvin M. Dyer and the Company.
 
      10.2(b) Combined Incentive and Nonstatutory Stock Option Plan, adopted February 22, 1989, and as amended
               April 30, 1994 and September 28, 1994, authorizing 1,200,000 shares of Common Stock for issuance
               pursuant to the combined Plan.
 
    10.5.1(b) Industrial Lease, dated January 28, 1992, by and between the Teachers Insurance and Annuity
               Association of America, as landlord, and the Company, as tenant.
 
    10.5.2(c) Industrial Leases, dated July 9, 1994, by and between Teachers Insurance and Annuity Association
               of America, as landlord, and the Company, as tenant.
 
    10.5.3(c) Amendment to Industrial Leases, dated February 15, 1994, by and between Teachers and Annuity
               Association of America, as landlord, and the Company, as tenant.
 
    10.5.4(d) Industrial Lease, dated March 9, 1995, by and between I-90 Lake Place II Limited Partnership, as
               landlord, and the Company, as tenant.
 
    10.6.1(b) Software License Agreement, dated June 4, 1994, by and between Music Technology Associates and the
               Company.
 
    10.6.2(b) Software Rights Purchase Agreement, dated May 5, 1994, by and between Music Technology Associates
               and the Company.
 
    10.6.3(c) Software License Agreement, dated August 6, 1994 by and between Dennis McMahon d/b/a Asystem, and
               the Company.
 
    10.6.4(a) Software Purchase Agreement, dated April 15, 1994 by and between Dennis McMahon d/b/a Asystem, and
               the Company.
</TABLE>
 
                                       38
<PAGE>
<TABLE>
<CAPTION>
EXHIBIT NO.  DESCRIPTION
-----------  --------------------------------------------------------------------------------------------------
<C>          <S>
    10.6.5(d) Software Purchase Agreement, dated November 10, 1994 by and between Dennis McMahon d/b/a Asystem,
               and the Company.
 
    10.6.6(d) Software Purchase Agreement, dated December 22, 1994 by and between Dennis McMahon d/b/a Asystem,
               and the Company.
 
    10.7.1(b) Reseller Agreement, dated January 3, 1992, by and between WestPoint Creative Ltd. and the Company.
 
    10.7.2(b) Reseller Agreement, dated December 31, 1991, by and between CPS Computer Distribution GmbH and the
               Company.
 
    10.7.3(b) Reseller Agreement, dated February 13, 1992, by and between Walop Electronics B.V. and the
               Company.
 
    10.8.1(b) Distribution Agreement, dated August 26, 1992, by and between Merisel, Inc. and the Company.
 
    10.8.2(b) Distribution Agreement, dated July 14, 1992, by and between Ingram Micro Inc. and the Company.
 
    10.9.1(b) OEM License Agreement, dated August 26, 1992, by and between MPC (Distribution) Ltd. and the
               Company.
 
    10.9.2(b) OEM License Agreement, dated January 8, 1994, by and between Ad Lib Multimedia Inc. and the
               Company.
 
    10.9.3(b) OEM License Agreement, dated October 26, 1994 by and between Media Vision Corporation
 
    10.9.4(b) Form of OEM License Agreement between various OEM licensees and the Company.
 
    10.9.5(a) OEM License Agreement, dated May 10, 1994, by and between International Business Machines and the
               Company.
 
    10.9.6(a) OEM License Agreement, dated May 17, 1994, by and between Gateway 2000 and the Company.
 
    10.9.7(a) OEM License Agreement, dated May 20, 1994, by and between ASCII Corporation and the Company.
 
    10.9.8(a) OEM License Agreement, dated May 20, 1994, by and between I-O Data Devices and the Company.
 
    10.9.9(e) OEM License Agreement, dated March 6, 1995, by and between Genoa Systems Corporation and the
               Company.
 
   10.9.10(e) OEM License Agreement, dated June 2, 1995, by and between Acer America Corporation and the
               Company.
 
   10.9.11(e) OEM License Agreement, dated June 5, 1995, by and between NEC Technologies, Inc. and the Company.
 
   10.10.1(b) Founders' Buy-Sell Agreement, dated February 22, 1989, by and among Mark R. McCulley, Raymond Bily
               and the Company.
 
   10.10.2(b) Addendum to Founder's Buy-Sell Agreement, dated April 30, 1994, by and among Mark R. McCulley,
               Raymond Bily and the Company.
</TABLE>
 
                                       39
<PAGE>
<TABLE>
<CAPTION>
EXHIBIT NO.  DESCRIPTION
-----------  --------------------------------------------------------------------------------------------------
<C>          <S>
   10.10.3(b) Shareholder Agreement, dated December 9, 1991, by and among Raymond Bily, Mark R. McCulley and
               certain shareholders of the Company, on the one hand, and the Company, on the other hand.
 
   10.10.4(e) Asset Purchase Agreement Among Midisoft Corporation, Knowledge Engineering, Inc. and certain
               shareholders of Knowledge Engineering, Inc. dated January 18, 1995.
 
   10.10.5(e) Asset Purchase and Sale Agreement by and among Midisoft Corporation, Ask Me Multimedia, Inc. and
               Michael O'Donnell dated April 14, 1995.
 
   10.11.1(c) U.S. Bank of Washington and the Company.
 
   10.11.2(b) Loan and Security Agreement, dated June 1, 1994, by and between Silicon Valley Bank and the
               Company.
 
   10.12.1(e) Severance letter, dated July 24, 1995.
 
      16.1(i) Letter of Price Waterhouse LLP, dated January 9, 1997 concerning change in certifying accountants
 
      16.2(j) Letter of Ernst & Young LLP, dated October 31, 1997 concerning change in certifying accountants
 
      23.1   Consent of Ernst & Young LLP
 
      23.2   Consent of Price Waterhouse LLP
</TABLE>
 
------------------------
 
(a) Incorporated by reference from the Company's Registration Statement on Form
    SB-2
    (S.E.C. File No. 33-80064).
 
(b) Incorporated by reference from the Company's Registration Statement on Form
    SB-2
    (S.E.C. File No. 33-62468-5).
 
(c) Incorporated by reference from the Company's Form 10-KSB filed March 30,
    1994
    (S.E.C. File No. 000-22172).
 
(d) Incorporated by reference from the Company's Form 10-KSB filed April 13,
    1995
    (S.E.C. File No. 000-22172).
 
(e) Incorporated by reference from the Company's Form 10-KSB/A filed August 4,
    1995
    (S.E.C. File No. 000-22172).
 
(f) Incorporated by reference from the Company's Form 10-KSB filed April 15,
    1997.
    (S.E.C. File No. 000-22172).
 
(g) Incorporated by reference from the Company's Form 10-KSB/A filed June 20,
    1997
    (S.E.C. File No. 000-22172).
 
(h) Incorporated by reference from the Company's Form 10-QSB filed November 12,
    1997
    (S.E.C. File No. 000-22172).
 
(i) Incorporated by reference from the Company's Form 8-K filed January 9, 1997
    (S.E.C. File No. 000-22172).
 
(j) Incorporated by reference from the Company's Form 8-K filed November 3, 1997
    (S.E.C. File No. 000-22172).
 
(k) Incorporated by reference from the Company's Form 10-KSB filed April 15,
    1998
    (S.E.C. File No. 000-22172).
 
                                       40

<PAGE>
                                   SIGNATURES
 
    In accordance with Section 13 or 15(d) of the Exchange Act, the registrant
caused this report to be signed on its behalf by the undersigned, thereunto duly
authorized.
 
                                MIDISOFT CORPORATION
                                (Registrant)
 
                                By:               /s/ LARRY FOSTER
                                     -----------------------------------------
                                                   Larry Foster,
                                               CHAIRMAN OF THE BOARD,
                                       PRESIDENT AND CHIEF EXECUTIVE OFFICER
 
Date: April 17, 1998
 
    In accordance with the Exchange Act, this report has been signed below by
the following persons on behalf of the registrant and in the capacities and on
the dates indicated.
 
          SIGNATURE                        TITLE                    DATE
------------------------------  ---------------------------  -------------------
 
       /s/ LARRY FOSTER         Chairman of the Board,
------------------------------    President and Chief          April 17, 1998
         Larry Foster             Executive Officer
 
                                Vice President, Finance and
      /s/ GARY M. CULLY           and Chief Financial
------------------------------    Officer (Principal           April 17, 1998
        Gary M. Cully             Accounting Officer)
 
        /s/ JOHN BAUER
------------------------------  Director                       April 17, 1998
          John Bauer
 
       /s/ MARSHA MURRY
------------------------------  Director                       April 17, 1998
         Marsha Murry
 
     /s/ A. PETER PARSONS
------------------------------  Director                       April 17, 1998
       A. Peter Parsons
 
      /s/ J. LARRY SMART
------------------------------  Director                       April 17, 1998
        J. Larry Smart
 
                                       41