<PAGE>   1

                                                                   EXHIBIT 10.43

                                CLOSING AGREEMENT


        This CLOSING AGREEMENT (the "Agreement") is made as of August 4, 1997,
by and among BRISTOL RETAIL SOLUTIONS, INC., a Delaware corporation (formerly,
Bristol Technology Systems, Inc.) ("Bristol"), PACIFIC MERGER CORP., a Delaware
corporation ("Purchaser"), PACIFIC CASH REGISTER COMPANY, a California
corporation ("Company"), ROBERT FREANEY and ABBASS BARZGAR (individually, a
"Shareholder" and, collectively, the "Shareholders").

        WHEREAS, Bristol, the Purchaser, the Company and the Shareholders are
parties to that certain Agreement and Plan of Merger dated as of June 27, 1997
(the "Merger Agreement"), pursuant to which the Shareholders have agreed to
convert their respective Company Shares into the right to receive cash and
Restricted Stock of Bristol, and pursuant to which the Company shall be merged
with and into the Purchaser;

        WHEREAS, Bristol, the Purchaser, the Company and the Shareholders wish
to enter into this Agreement to address certain matters which have changed
subsequent to June 27, 1997.

        NOW, THEREFORE, for good and valuable consideration, receipt and
sufficiency of which is hereby aknowledged, the parties agree as follows:

        1. Reduction in Required Pre-Tax Earnings. The parties hereby agree that
the provisions of Section 1.5 of the Merger Agreement, including, without
limitation, Section 1.5(b) of the Merger Agreement, which state that a number of
the Additional Restricted Shares will be returned to Bristol if the Company's
Pre-Tax Earnings for the fiscal year ending December 31, 1997 are less than
Eighty Thousand Dollars ($80,000), are hereby amended to provide that a number
of the Additional Restricted Shares will be returned to Bristol if the Company's
Pre-Tax Earnings for the fiscal year ending December 31, 1997 are less than
Seventy Thousand Dollars ($70,000). In the event that the Company's Pre-Tax
Earnings for the fiscal year ending December 31, 1997 are less than Seventy
Thousand Dollars ($70,000), then Robert Freaney will return $4.6865 worth of the
Additional Restricted Shares to Bristol for each dollar by which Seventy
Thousand Dollars ($70,000) exceeds the Company's Pre-Tax Earnings for that
period. The remaining provisions of Section 1.5 of the Merger Agreement shall
remain in full force and effect.


        2. Reduction in Required Anticipated Closing Date Net Worth. The parties
hereto hereby agree that the provisions of Section 1.6 of the Merger Agreement,
which state that Escrowed Stock shall be held until such time as Bristol and the
Purchaser can verify that Company's Anticipated Closing Date Net Worth is at
least One Hundred Seventeen Thousand Dollars ($117,000), are here by amended to
provide that Escrowed Stock shall be held until such time as Bristol and the
Purchaser can verify that Company's Anticipated Closing Date Net Worth is at
least One Hundred Seven Thousand Dollars ($107,000). The remaining provisions of
Section 1.6 of the Merger Agreement shall remain in full force and effect.

        3. Amendment of Definition of Effective Bristol Share Price. The parties
hereto hereby agree that the definition of "Effective Bristol Share Price" set
forth in Article 0 of the Merger Agreement is hereby amended in full to read as
follows: "Effective Bristol Share Price means the closing price per share of
Bristol's publicly traded Common Stock on July 30, 1997. The closing price of
Bristol's publicly traded Common Stock on July 30, 1997, for purposes of this
definition shall be that day's last trade price as reported on NASDAQ."

        4. Definition of Terms. Unless otherwise defined herein, all capitalized
terms used herein shall have the meanings ascribed to them in the Merger
Agreement.

        5. Further Assurances. The parties hereto shall execute and deliver all
such other and further documents and perform all further acts that may be
reasonably necessary to effectuate the terms and provisions of this Agreement.



<PAGE>   2

        6. Incorporation by Reference/Conflicts. Except as amended by this
Agreement, the provisions of the Merger Agreement are incorporated herein by
reference. If there is any conflict between the provisions of this Agreement and
any provisions of the Merger Agreement, the provisions of this Agreement shall
prevail. Except as hereinabove set forth in this Agreement, the Merger Agreement
shall remain unchanged and in full force and effect.

        IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed by their respective officers thereunto duly authorized as of the date
first above stated.


"BRISTOL"                          Bristol Retail Solutions, Inc.,
                                   a Delaware corporation


                                   By: 
                                      -----------------------------
                                   Its: 
                                        ---------------------------


"PURCHASER"                        Pacific Merger Corp.,
                                   a Delaware corporation


                                   By: 
                                      -----------------------------
                                   Its: 
                                        ---------------------------


"COMPANY"                          Pacific Cash Register Company,
                                   a California corporation

                                   By: 
                                      -----------------------------
                                   Its: 
                                        ---------------------------

"SHAREHOLDERS"                    
                                   --------------------------------
                                   ROBERT FREANEY


 .                                  --------------------------------
                                   ABBASS BARZGAR



                                      -2-