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                                                           EXHIBIT 10.3
                                                           ------------

                               FIRST AMENDMENT TO
                          LOAN AND SECURITY AGREEMENT

          THIS FIRST AMENDMENT TO LOAN AND SECURITY AGREEMENT this "First
Amendment") is dated as of May 31, 1996 and is entered into between SCIENTIFIC
TECHNOLOGIES INCORPORATED, an Oregon corporation doing business in California as
Oregon Scientific Technologies (the "Borrower"), and BANK OF THE WEST, a
California banking corporation (the "Bank").

                                   RECITALS:
                                   ---------
                                        
          A.  Borrower and Bank have entered into that certain Loan and Security
Agreement dated November 29, 1995 4 (the "Loan Agreement") and that certain
Equipment Purchase Line Note dated December 6, 1995 (the "Equipment Purchase
Line Note");

                                 B.  Borrower and Bank intend to further amend
the Loan Agreement as provided by this First Amendment.

                                  AMENDMENT:
                                  ----------

          NOW, THEREFORE, Borrower and Bank hereby agree as follows:

          1.   This First Amendment shall modify and, to the extent inconsistent
with, amend the Loan Agreement and/or the Equipment Purchase line Note.  Any
capitalized term not specifically defined herein shall have the meaning ascribed
to it in the Loan Agreement.

          2.   The last sentence of Section 3.1(a) of the Loan Agreement is
hereby deleted in its entirety and is replaced with the following:

          For the purpose of this Agreement, "Draw Period" shall mean the period
          between the date of this Loan and Security Agreement and the earlier
          of: (i) May 31, 1996 or (ii) the date on which the aggregate of all
          advances made pursuant to this Section 3.1 equals Five Hundred
          Thousand and 00/100 Dollars ($500,000.00).

          3.   The last sentence of Section 3.3(c) of the Loan Agreement is
hereby deleted in its entirety and is replaced with the following:

          For the purpose of this Agreement, the "Term Maturity Date" shall mean
May 31, 1996.

          4.   The second sentence of the first paragraph of Section 4.1 of the
Loan Agreement is hereby deleted in its entirety and is replaced with the
following:

          Borrower's right to obtain advances under Section 2.1 and to enter
          into foreign exchange contracts under the FX Facility provided by
          Section 14.1 shall remain in full force and effect until May 31, 1996,
          and shall continue on a month-to-month basis thereafter until
          terminated by either party on thirty (30) days prior written notice to
          the other.

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          5.   Section 10.11 of the Loan Agreement is hereby deleted in its
entirety and is replaced with the following:

          10.11 FINANCIAL STATEMENTS. Borrower agrees to deliver to Bank the
          following reports, statements, certificates, or other materials, which
          materials will be in a form acceptable to Bank and will be delivered
          within the time periods specified in this section 10.11: within forty-
          five (45) days after the end of each of Borrower's fiscal quarters, a
          balance sheet, and a profit and loss statement, which financial
          information shall cover Borrower's operations during such period;
          within ninety (90) days after the end of each of Borrower's fiscal
          years, a statement of the financial condition of Borrower for each
          such fiscal year (including, but not limited to, a long-form balance
          sheet and profit and loss statement, audited by certified public
          accountants acceptable to Bank); upon Bank's request, a statement of
          all accounts receivable and accounts payable as of the end of the
          immediately preceding fiscal quarter; and any other report requested
          by Bank relating to the Collateral and the financial condition of
          Borrower. If Borrower is required hereunder to deliver fiscal year-end
          statements of Borrower's financial condition which are prepared on an
          audited basis by independent certified public accountants, then,
          contemporaneously therewith, Borrower shall also deliver to Bank an
          unqualified opinion thereon by said accountants. Borrower shall comply
          with any request and shall treat and written request as a continuing
          obligation until expressly modified or terminated in writing.

          6.   The last sentence of the fifth paragraph of the Equipment
Purchase Line Note is hereby deleted in its entirety and is replaced with the
following:

          For the purpose of this Note, the "Term Maturity Date" shall mean May
31, 1996.

          7.   Concurrently with the execution of this First Amendment, Borrower
shall pay to Bank a fee in an annual amount equal to Six Thousand Five Hundred
Dollars ($6,500.00), which fee shall represent an unconditional and
nonrefundable payment to Bank in consideration of Bank's agreement to enter into
this First Amendment.

          8.   Bank's duties to extend and renew the Obligations and to make
advances in accordance with this First Amendment shall be subject to (i) there
being no outstanding and uncured details under the Loan Agreement and (ii) the
satisfaction of each of the conditions precedent set forth in Article 6 of the
Loan Agreement, each of which is incorporated herein by this reference.

          9.   Except as amended by this First Amendment, all of the terms and
conditions of the Loan Agreement (and each and every document or instrument
executed and delivered in connection therewith) is and shall remain in full
force and effect.

         10.   Borrower hereby ratifies, reaffirms, and remakes as of the date
hereof each and every representation and warranty contained in the Loan
Agreement or in any document incident thereto connected therewith as amended by
this First Amendment.

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     IN WITNESS WHEREOF, Borrower has executed and delivered this First
Amendment to Bank on the date first above written at Walnut Creek, California.

                         "BORROWER"

                         SCIENTIFIC TECHNOLOGIES INCORPORATED,
                         an Oregon corporation doing business in California as
                         Oregon Scientific Technologies

                         By: s/l Joseph J. Lazzara
                             ---------------------

                         Its: President & CEO
                              ---------------

     IN WITNESS WHEREOF, Bank hereby accepts this First Amendment to be
effective as of the date first above written in Walnut Creek, California.

                         "BANK"

                         BANK OF THE WEST,
                         a California banking corporation

                         By: s/l R. W. Hansen
                             ----------------

                         Its: Vice President
                              --------------

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