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                                                                  EXHIBIT 4.18.1

                              WAIVER AND AGREEMENT

        THIS Waiver and Agreement ("Agreement") is made as of September 24,
2001, by and between Swartz Private Equity, LLC ("Swartz" or the "Investor") and
Patriot Scientific Corporation ("Patriot" or the "Company"), a Delaware
corporation, with respect to the following:


                                    RECITALS:

        WHEREAS, the Company and Swartz entered into an Investment Agreement
(the "Investment Agreement") dated on or about May 2, 2000, whereby the Company
has the right to sell and Swartz has agreed to purchase, from time to time as
provided in the Investment Agreement, shares of the Company's Common Stock for a
maximum aggregate offering amount of Thirty Million Dollars ($30,000,000);

        WHEREAS, unless otherwise noted, capitalized terms herein shall have the
meanings ascribed to them in the Investment Agreement;

        WHEREAS, the Company desires to initiate a Put having a Put Date of
September 24, 2001 ("Put #10") under the terms set forth herein and in the Put
Notice dated September 24, 2001 attached hereto as Exhibit A;

        WHEREAS, Swartz has delivered to the Company several cash payments in
advance for application to Put #10 and to future Puts, as described herein;

        WHEREAS, Section 2.3.1(b) of the Investment Agreement provides, in
pertinent part, as follows:

        Notwithstanding the above, in no event shall the First Put Limit, the
        Second Put Limit, or the sum of the First Put Limit and the Second Put
        Limit . . . (ii) exceed 20% of the sum of the aggregate daily reported
        Trading Volumes in the outstanding Common Stock on the Company's
        Principal Market, excluding any block trades which exceed "X" (as
        defined above) shares of Common Stock made by persons other than the
        Investor or any affiliates of the Investor, for the twenty (20) Trading
        Days immediately preceding the Put Date. . .

        WHEREAS, the limitation in the immediately preceding recital shall be
referred to herein as the "Lookback Volume Limitation," and

        WHEREAS, the Company desires to define various terms for Put #10, as
described herein.


                                     TERMS:

        NOW, THEREFORE, in consideration of the mutual promises,
representations, warranties, covenants and conditions set forth in this
Agreement and for other good and valuable


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consideration, the receipt and sufficiency of which is hereby acknowledged, the
parties hereto agree as follows:

1.      In conjunction with the Put ("Put #9") having a Put Date of August 24,
2001, with Put #10 and potentially in conjunction with future Puts, Swartz has
delivered to the Company the sum of three hundred and fifty thousand dollars
($350,000) in three (3) cash payments, as follows: Swartz paid $100,000 to the
Company on or about 8/27/2001, paid $125,000 to the Company on or about
9/10/2001, and paid $125,000 to the Company on or about 9/24/2001. The above
payments shall be collectively referred to herein as the "Credit." Of this
$350,000, as of the date hereof $135,000 has been consumed by Put #9 leaving a
residual Credit of $215,000, which shall be referred to herein as the "Residual
Credit."

2.      The Second Put Limit for Put #10 is hereby redefined from its definition
in the Investment Agreement to the following: The "Second Put Limit" shall equal
zero (0) shares.

3.      The Second Pricing Period is hereby null and void with respect to Put
#10.

4.      The First Pricing Date for Put #10 is hereby redefined from its
definition in the Investment Agreement to the following: The "First Pricing
Date" shall mean the Last Evaluation Day (as defined below) for Put #10.

5.      The Lookback Volume Limitation shall not apply with respect to Put #10.

6.      The Total Dollar Amount for Put #10 is hereby redefined from its
definition in the Investment Agreement to the following: The "Total Dollar
Amount" shall equal the summation of the Daily Dollar Amounts (as defined below)
over the N Evaluation Days (where N is defined below) of the First Pricing
Period (as redefined herein). For each Evaluation Day of the First Pricing
Period (as redefined herein), the "Daily Dollar Amount" shall equal the product
of

        (I) the lesser of (a) the volume weighted average price ("VWAP") per
        share, as determined by Bloomberg L.P. for that Evaluation Day,
        multiplied by 0.70, or (b) the VWAP per share, for that Evaluation Day,
        minus $0.05 per share, multiplied by

        (II) the Daily Accrued Amount (as defined below) for that Evaluation
        Day.


        For purposes hereof, "N" shall be defined as the number of Evaluation
Days required to make up the First Pricing Period for Put #10 in order to cause
the Total Dollar Amount (as defined herein) to equal the Residual Credit (after
accounting for the Last Day Volume Cutback, as defined below). The date of the
last Evaluation Day in Put #10 shall re referred to herein as the "Last
Evaluation Day."

        For purposes hereof, the "Daily Accrued Amount" shall mean, with respect
to each of the N Evaluation Days of the First Pricing Period, (i) the daily
trading volume for that Evaluation Day less daily Excludable Block Trades (as
defined below) for that Evaluation Day, multiplied by (ii) 0.20.


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        For purposes hereof, "Excludable Block Trades" shall mean block trades
which exceed "X" shares of Common Stock made by persons other than the Investor
or any affiliates of the Investor, for all Evaluation Days (as defined in
Section 2.3.1(b) of the Investment Agreement) in the First Pricing Period (this
limitation is referred to herein and in the Investment Agreement as the "First
Volume Limitation"), where "X" shall equal the lesser of (x) 100,001 shares or
(y) 25% of that day's Trading Volume.

        If the sum of the Daily Dollar Amounts for all previous Evaluation Days
in the First Pricing Period for Put #10 together with the Daily Dollar Amount
for the Nth Evaluation Day exceeds the Residual Credit, then the Daily Accrued
Amount for the Nth Evaluation Day shall be reduced such that the sum of the
Daily Dollar Amounts for all previous Evaluation Days in the First Pricing
Period for Put #10 together with the Daily Dollar Amount for the Nth Evaluation
Day shall equal the Residual Credit (the "Last Day Volume Cutback").

7.      The First Put Limit for Put #10 is hereby redefined from its definition
in the Investment Agreement to the following: The "First Put Limit" shall mean
the sum of the Daily Accrued Amounts from each Evaluation Day in the First
Pricing Period.

        In the event that the First Put Limit exceeds the number of Remaining
Registered Put Shares (as defined below) under the effective Equity Line
Registration Statement (as defined below), then the difference between the First
Put Limit and the number of Remaining Registered Put Shares shall be issued to
Swartz as restricted shares (the "Restricted Shares"). Any such Restricted
Shares issued to Swartz shall have "piggyback" registration rights with regard
to the next registration statement filed by the Company.

        For purposes hereof, "Remaining Registered Put Shares" shall mean

        (I) the number of shares of the Company's common stock registered in the
    Equity Line Registration Statement to cover the resale of the Put Shares
    issued or issuable under the Equity Line, minus

        (II) the number of Put Shares that have been issued and sold to Swartz
    prior to the beginning of Put #10.

        For purposes hereof, "Equity Line Registration Statement" shall mean the
Company's registration statement on form S-3 filed on or about May 5, 2000 (File
#333-36418), and declared effective on or about June 23, 2000, which covers the
resale of the shares issuable under the Investment Agreement and the related
warrants.

8.      Notwithstanding the terms of Section 2.4.2 of the Investment Agreement,
the Purchase Warrant issued to Swartz by the Company for Put #10 shall be a
warrant to purchase a number of shares of common stock equal to 100% of the
total number of Put Shares purchased by Swartz in Put #10 at an Initial Exercise
Price calculated as follows: The Put #10 Purchase Warrant Initial Exercise Price
shall equal the aggregate purchase price of the Put Shares purchased by Swartz
in Put #10 divided by the total number of Put Shares purchased by Swartz in Put
#10. In the event that the number of Purchase Warrants to be issued pursuant to
this Agreement exceeds the number of Remaining Registered Purchase Warrant
Shares (as defined


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below) under the effective Equity Line Registration Statement, then a number of
warrants (the "Restricted Warrants") equal to the difference of (i) the number
of Purchase Warrants to be issued pursuant to this Agreement, minus (ii) the
number of Remaining Registered Purchase Warrant Shares, shall be issued to
Swartz without an effective registration statement covering the resale of the
underlying common stock. Any such Restricted Warrants issued to Swartz shall
have "piggyback" registration rights with regard to the next registration
statement filed by the Company. For purposes hereof, "Remaining Registered
Purchase Warrant Shares" shall mean

        (I) the number of shares of the Company's common stock registered in the
    Equity Line Registration Statement to cover the resale of the shares issued
    or issuable upon the exercise of Purchase Warrants that are issued or
    issuable to Swartz under the Equity Line, minus

        (II) the number of shares underlying Purchase Warrants that have been
    issued and sold to Swartz prior to the beginning of Put #10.


9.      The Restricted Shares and the Restricted Warrants shall be issued to
Swartz in a private placement (the "Private Placement"), separate from the
Investment Agreement. The purchase price of the Restricted Shares and the
Restricted Warrants shall be deemed paid by the applicable portion of the
Residual Credit. In conjunction with the Private Placement, Swartz shall provide
the Company with the customary representations regarding accredited and
sophisticated investor status.

10.     The Total Dollar Amount, as defined herein, shall be covered by the
Residual Credit and no additional amounts shall be due to the Company from
Swartz for the Put Shares and Purchase Warrants purchased in Put #10 and the
Restricted Shares and Restricted Warrants, if any, purchased by Swartz in the
Private Placement as required herein.

11.     The terms of this Agreement apply to Put #10 only, and shall have no
force or effect on any other past or future Puts.



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12.     Except as specifically set forth herein, all other terms of the
Investment Agreement shall remain in full force and effect.


        IN WITNESS WHEREOF, the undersigned have executed this Agreement as of
this 24th day of September, 2001.

                                        AGREED AND ACKNOWLEDGED:
SWARTZ PRIVATE EQUITY, LLC.             PATRIOT SCIENTIFIC CORPORATION



By: /S/ ERIC S. SWARTZ                  By: /S/ LOWELL W. GIFFHORN
   -------------------------------         -------------------------------
    Eric S. Swartz, Manager                 Lowell Giffhorn, CFO


300 Colonial Center Parkway             10989 Via Frontera
Suite 300                               San Diego, CA 92127
Roswell, GA  30076                      Telephone: (858) 674-5000
Telephone: (770) 640-8130               Facsimile:   (858) 674-5005
Facsimile:  (770) 640-7150


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