REVOLVING PROMISSORY NOTE

Exhibit 10.2

REVOLVING PROMISSORY NOTE

This Revolving Promissory Note (the “Note”) is executed pursuant to that certain Loan Agreement (as amended, modified, restated or replaced from time to time, the “Loan Agreement”) dated March 10, 2005, by and between Staktek Holdings, Inc ., a Delaware corporation (the “Borrower”) and Guaranty Bank (the “Bank”). Advances to be made hereunder by Bank shall be made in reliance upon each and all of the terms, conditions, representations, warranties, covenants and agreements of the Loan Agreement. In no event will Bank have any obligation to advance any proceeds of this Note unless Borrower fully satisfies all conditions thereto set forth in the Loan Agreement.

For value received, Borrower promises to pay to the order of Bank, at the office of Bank at 8333 Douglas Avenue, Dallas, Dallas County, Texas 75225 (or at such other place as Bank may hereafter direct Borrower), the principal sum of TWENTY MILLION AND 00/100 DOLLARS ($20,000,000.00) , or the aggregate amount of all unpaid advances made hereunder, whichever is the lesser, together with interest on the outstanding portion thereof for the period such sums are unpaid, as hereinafter provided, on or before the Maturity Date.

1. Definitions . Capitalized terms which are used in this Note and are not otherwise defined are used with the meanings provided for them in the Loan Agreement, unless the context clearly requires otherwise. As used in this Note, the following terms shall have the meanings indicated opposite them:

“ Additional Costs ” — Any costs, losses or expenses incurred by Bank which it determines are attributable to its making or maintaining the Loan, or its obligation to make any Loan advances, or any reduction in any amount receivable by Bank under the Loan or this Note.

“ Applicable Margin ” — The following percentages per annum, based upon the Borrower’s Deposit/Sweep Balances:

Any increase or decrease in the Applicable Margin resulting from a change in Borrower’s

Deposit/Sweep Balances shall become effective as of the first Business Day following the date a change in Borrower’s Deposit/Sweep Balances occurs that effects such a change in the Applicable Margin.

“ Applicable Rate ” — The Commercial Based Rate as to that portion of the Principal Amount bearing interest at the Commercial Based Rate and the LIBOR Based Rate as to each LIBOR Amount.

“ Commercial Based Rate ” — The Base Rate, minus the Applicable Margin per annum. The Borrower understands that the Commercial Based Rate may not be the lowest rate of interest charged to or paid by customers of Bank or of any other financial institution, that the Commercial Based Rate is not necessarily more favorable than another rate or index, and that rates on other loans or credit facilities may be based on indices other than the Commercial Based Rate.

“ Interest Period ” — The period during which interest at the LIBOR Based Rate, determined as provided in this Note, shall be applicable to the LIBOR Rate Request Amount in question, provided, however, that each such period shall be either one (1) month, two (2) months or three (3) months which shall be measured from the date specified by Borrower in each LIBOR Rate Request for the commencement of the computation of interest at the LIBOR Based Rate, to the numerically corresponding day in the calendar month in which such period terminates (or, if there be no numerical correspondent in such month, or if the date selected by Borrower for such commencement is the last LIBOR Business Day of a calendar month, then the last LIBOR Business Day of the calendar month in which such period terminates, or if the numerically corresponding day is not a LIBOR Business Day then the next succeeding LIBOR Business Day, unless such next succeeding LIBOR Business Day enters a new calendar month, in which case such period shall end on the next preceding LIBOR Business Day); in no event shall any such period be selected which extends beyond the Maturity Date.

“ LIBOR Amount ” — Each portion of the Principal Amount bearing interest at an applicable LIBOR Based Rate pursuant to a LIBOR Rate Request.

“ LIBOR Based Rate ” — With respect to any LIBOR Amount, the LIBOR Rate plus the Applicable Margin.

“ LIBOR Business Day ” — Any day on which commercial banks are open for domestic and international business (including dealings in U.S. Dollar deposits) in New York City, New York and Dallas, Texas.

“ LIBOR Rate ” — The rate per annum determined by Bank (rounded upward, if necessary, to the nearest 1/16 of 1%) equal to the offered rate (and not the bid rate) for deposits in U.S. Dollars of amounts comparable to the LIBOR Rate Request Amount for the same period of time as the Interest Period selected by Borrower in the LIBOR Rate Request, as set forth on the LIBOR Reference Source at approximately 10:00 a.m. (Dallas, Texas time) on the first day of the applicable Interest Period.

“ LIBOR Rate Request ” — Borrower’s telephonic notice (to be promptly confirmed in writing by Borrower which must be received by Bank before such LIBOR Rate Request will be put into effect by Bank), to be received by Bank by 12:00 o’clock Noon (Dallas, Texas time) three (3) LIBOR Business Days prior to the LIBOR Business Day specified in the LIBOR Rate Request for the commencement of the Interest Period, evidencing (i) Borrower=s election to have (a) all or any portion of the Principal Amount which is not then the subject of an Interest Period (other than an Interest Period which is terminating on such LIBOR Business Day), and/or (b) all or any portion of any advance of Loan proceeds which is to be made on such LIBOR Business Day, bear interest at the LIBOR Based Rate, and (iii) specifying the Interest Period desired by Borrower in respect of the amount specified.

“ LIBOR Rate Request Amount ” — The amount, to be specified by Borrower in each LIBOR Rate Request, which Borrower desires to bear interest at the LIBOR Based Rate and which shall in no event be less than $100,000.00 and, at Bank’s option, incremental amounts of $100,000.00 each.

“ LIBOR Reference Source ” — The display for LIBOR rates appearing on Telerate Page 3750 (or any successor page) as the London interbank offered rate for deposits in U.S. Dollars at approximately 11:00 a.m. (London Time), for a term comparable to such Interest Period.

“ Loan ” — The revolving loan to be made to Borrower by Bank pursuant to Section 1(a) of the Loan Agreement and evidenced hereby.

“ Loan Agreement ” — The Loan Agreement dated March 10, 2005, between Bank and Borrower pursuant to which the Loan is being made, and any amendments, modifications, restatements, or replacements thereof.

“ Loan Documents ” — The Loan Agreement, this Note, and all other documents, agreements, and certificates executed and delivered by any person or entity in connection with any thereof, and any and all amendments thereto and modifications thereof.

“ Maturity Date ” — March 9, 2006, being the date this Note becomes due and payable in its entirety.

“ Note ” — This Revolving Promissory Note in the original principal amount of $20,000,000.00 executed by Borrower and payable to the order of Bank and any and all renewals, extensions and rearrangements thereof.

“ Obligated Parties ” — Borrower and any endorser, guarantor, surety or other person liable for the payment of this Note.

“ Principal Amount ” — That portion of the Loan evidenced hereby as is from time to time unpaid and outstanding.

“ Regulation D ” — Regulation D of the Board of Governors of the Federal Reserve System, as from time to time amended or supplemented.

“ Regulation ” — With respect to the charging and collecting of interest at the LIBOR Based Rate, any United States federal, state or foreign laws, treaties, rules or regulations whether now in effect or hereinafter enacted or promulgated (including Regulation D) or any interpretations, directives or requests applying to a class of depository institutions including Bank under any United States federal, state or foreign laws or regulations by any court or governmental or monetary authority charged with the interpretation or administration thereof.

“ Reserve Requirement ” — The average maximum rate at which reserves (including any marginal, supplemental or emergency reserves) are required to be maintained under Regulation D by member banks of the Federal Reserve System in New York City with deposits exceeding one billion U.S. Dollars against “Eurocurrency Liabilities,” as such quoted term is used in Regulation D. Without limiting the effect of the foregoing, the Reserve Requirement shall reflect any other reserves required to be maintained by such member banks by reason of any Regulation against (i) any category of liabilities which includes deposits by reference to which the LIBOR Rate is to be determined as provided in this Note, or (ii) any category of extensions of credit or other assets which includes loans the interest rates on which is determined on the basis of rates referred to in the definition of “LIBOR Rate” set forth above.

2. Interest .

2.1 As herein provided, the unpaid Principal Amount of this Note (or portions thereof) from time to time outstanding shall bear interest prior to maturity at the Commercial Based Rate and/or one or more applicable LIBOR Based Rates (as elected in the manner specified in this Note), provided that in no event shall the Applicable Rate exceed the Maximum Lawful Rate. The foregoing notwithstanding, if at any time the Applicable Rate exceeds the Maximum Lawful Rate, the rate of interest payable under this Note shall be limited to the Maximum Lawful Rate, but any subsequent reductions in the Commercial Based Rate or the LIBOR Based Rate, as the case may be, shall not reduce the Applicable Rate below the Maximum Lawful Rate until the total amount of interest accrued on this Note equals the total amount of interest which would have accrued at the Applicable Rate if the Applicable Rate had at all times been in effect. Interest prior to maturity on this Note shall be calculated at a daily rate based on a year of 360 days, with the daily rate so determined being applied for the actual number of days elapsed, provided that in no event shall the amount or rate of interest payable hereunder exceed the Maximum Lawful Amount. Interest on the Principal Amount (whether computed at the Commercial Based Rate or at the LIBOR Based Rate) shall be payable monthly on the last day of each month beginning the last day of April, 2005, and the remaining Principal Amount and all accrued and unpaid interest shall be due and payable in full on the Maturity Date. Any Principal Amount owing hereunder may be paid in full or in part prior to maturity without penalty or premium, except as otherwise provided in Section 2.9 as to any Principal Amount bearing interest at the LIBOR Based Rate.

2.2 Borrower shall have the option, subject to the terms and conditions hereinafter set forth, of paying interest on the Principal Amount or portions thereof at the Commercial Based Rate or the LIBOR Based Rate as herein provided. Except as to that portion or portions of the Principal Amount bearing interest at the LIBOR Based Rate, the Principal Amount, from time to time

outstanding, shall bear interest at the Commercial Based Rate. If Borrower desires the application of the LIBOR Based Rate, it shall submit a LIBOR Rate Request to Bank. Such LIBOR Rate Request shall be irrevocable, subject to Borrower’s right to convert the rate of interest payable hereunder with respect to any LIBOR Amount from the LIBOR Based Rate to the Commercial Based Rate as hereinafter provided. In the event that Borrower fails to submit a LIBOR Rate Request with respect to an existing LIBOR Amount not later than 12 o’clock Noon (Dallas, Texas time) three (3) LIBOR Business Days prior to the LIBOR Business Day specified in the LIBOR Rate Request for the commencement of the applicable Interest Period, the LIBOR Amount in question shall bear interest, commencing at the end of such Interest Period, at the Commercial Based Rate.

2.3 Bank, at its option, may honor a LIBOR Rate Request which is submitted less than three (3) LIBOR Business Days prior to the LIBOR Business Day specified in the LIBOR Rate Request for the commencement of the applicable Interest Period; provided, however, Bank is not and shall not thereafter be bound to honor such a request.

2.4 Any language to the contrary hereinabove notwithstanding, there may be no