SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G
                                  Rule 13d-102

                   Under the Securities Exchange Act of 1934
                               (Amendment No. 1)*

                               Simtek Corporation
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                                (Name of Issuer)

                                  Common Stock
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                         (Title of Class of Securities)

                                   829204106
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                                 (CUSIP Number)

                                   12/31/2007
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            (Date of Event which Requires Filing of this Statement)

      Check the appropriate box to designate the rule pursuant to which
this Schedule is filed:
                               |_| Rule 13d-1 (b)
                               |_| Rule 13d-1 (c)
                               |X| Rule 13d-1 (d)

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      * The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which
would alter disclosures provided in a prior cover page.

      The information required on the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).

Page 1 of 7 Pages


CUSIP No. 829204106
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(1) Names of reporting persons.

    RENAISSANCE US GROWTH INVESTMENT TRUST PLC
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(2) Check the appropriate box if a member of a group (see instructions)   (a)|_|
                                                                          (b)|_|
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(3) SEC use only.

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(4) Citizenship or place of organization.

    UNITED KINGDOM
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Number of shares beneficially owned by each reporting person with:

    (5) Sole voting power:
        0

    (6) Shared voting power:
        1,107,936 (1)

    (7) Sole dispositive power:
        0

    (8) Shared dispositive power:
        1,107,936 (2)

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(9) Aggregate amount beneficially owned by each reporting person.

    1,107,936
--------------------------------------------------------------------------------
(10) Check if the aggregate amount in Row (9) excludes certain shares       |_|
     (see instructions).
--------------------------------------------------------------------------------
(11) Percent of class represented by amount in Row 9.

     6.6%
--------------------------------------------------------------------------------
(12) Type of reporting person (see instructions).

     IV
--------------------------------------------------------------------------------

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(1)     Renaissance US Growth Investment Trust PLC ("R US") is the owner of
        record of the shares and shares voting power over the shares with RENN
        Capital Group, Inc., its investment adviser ("RENN").

(2)     R US shares dispositive power over the shares with RENN.

Page 2 of 7 Pages


CUSIP No. 829204106
--------------------------------------------------------------------------------
(1) Names of reporting persons.

    US SPECIAL OPPORTUNITIES TRUST PLC
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(2) Check the appropriate box if a member of a group (see instructions)   (a)|_|
                                                                          (b)|_|
--------------------------------------------------------------------------------
(3) SEC use only.

--------------------------------------------------------------------------------
(4) Citizenship or place of organization.

    UNITED KINGDOM
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Number of shares beneficially owned by each reporting person with:

    (5) Sole voting power:
        0

    (6) Shared voting power:
        1,007,173 (1)

    (7) Sole dispositive power:
        0

    (8) Shared dispositive power:
        1,007,173 (2)

--------------------------------------------------------------------------------
(9) Aggregate amount beneficially owned by each reporting person.

    1,007,173
--------------------------------------------------------------------------------
(10) Check if the aggregate amount in Row (9) excludes certain shares       |_|
     (see instructions).
--------------------------------------------------------------------------------
(11) Percent of class represented by amount in Row 9.

     6.0%
--------------------------------------------------------------------------------
(12) Type of reporting person (see instructions).

     IV
--------------------------------------------------------------------------------

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(1)     US Special Opportunities Trust PLC (formerly BFS US Special
        Opportunities Trust PLC) ("USO") is the owner of record of the shares
        and shares voting power over the shares with RENN Capital Group, Inc.,
        its investment adviser ("RENN").

(2)     USO shares dispositive power over the shares with RENN.

Page 3 of 7 Pages


CUSIP No. 829204106
--------------------------------------------------------------------------------
(1) Names of reporting persons.

    RENN Capital Group, Inc.
--------------------------------------------------------------------------------
(2) Check the appropriate box if a member of a group (see instructions)   (a)|_|
                                                                          (b)|_|
--------------------------------------------------------------------------------
(3) SEC use only.

--------------------------------------------------------------------------------
(4) Citizenship or place of organization.

    TEXAS
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Number of shares beneficially owned by each reporting person with:

    (5) Sole voting power:
        14,082

    (6) Shared voting power:
        2,115,109 (1)

    (7) Sole dispositive power:
        14,082

    (8) Shared dispositive power:
        2,115,109 (2)

--------------------------------------------------------------------------------
(9) Aggregate amount beneficially owned by each reporting person.

    2,129,191
--------------------------------------------------------------------------------
(10) Check if the aggregate amount in Row (9) excludes certain shares       |_|
     (see instructions).
--------------------------------------------------------------------------------
(11) Percent of class represented by amount in Row 9.

     12.3%
--------------------------------------------------------------------------------
(12) Type of reporting person (see instructions).

     IA
--------------------------------------------------------------------------------

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(1)     RENN is investment adviser to USO and investment manager to R US.  R US
        and USO share voting power over their shares with RENN.

(2)     R US and USO share dispositive power over their shares with RENN.

Page 4 of 7 Pages


CUSIP No. 829204106
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(1) Names of reporting persons.

    Cleveland, Russell
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(2) Check the appropriate box if a member of a group (see instructions)   (a)|_|
                                                                          (b)|_|
--------------------------------------------------------------------------------
(3) SEC use only.

--------------------------------------------------------------------------------
(4) Citizenship or place of organization.

    US
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Number of shares beneficially owned by each reporting person with:

    (5) Sole voting power:
        14,082

    (6) Shared voting power:
        2,115,109 (1)

    (7) Sole dispositive power:
        14,082

    (8) Shared dispositive power:
        2,115,109

--------------------------------------------------------------------------------
(9) Aggregate amount beneficially owned by each reporting person.

    2,129,191
--------------------------------------------------------------------------------
(10) Check if the aggregate amount in Row (9) excludes certain shares       |_|
     (see instructions).
--------------------------------------------------------------------------------
(11) Percent of class represented by amount in Row 9.

     12.3%
--------------------------------------------------------------------------------
(12) Type of reporting person (see instructions).

     IN
--------------------------------------------------------------------------------

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(1)     Mr. Cleveland is President and Chief Executive Officer of RENN which is
        investment adviser to USO and R US. R US and USO share voting power over
        their shares with RENN.

Page 5 of 7 Pages


Item 1(a). Name of Issuer:

           Simtek Corporation

Item 1(b). Address of Issuer's Principal Executive Offices:

           4250 Buckingham Drive, #100
           Colorado Springs, CO  80907


Item 2(a). Name of Person Filing:

           RENAISSANCE US GROWTH INVESTMENT TRUST PLC
           US SPECIAL OPPORTUNITIES TRUST PLC
           RENN Capital Group, Inc.
           Cleveland, Russell

Item 2(b). Address or Principal Business Office or, If None, Residence:

           c/o RENN Capital Group, Inc., 8080 N. Central Expressway, Suite 210,
           LB-59, Dallas, TX  75026

Item 2(c). Citizenship:

           UNITED KINGDOM, TEXAS, US

Item 2(d). Title of Class of Securities:

           Common Stock

Item 2(e). CUSIP No.:

           829204106

Item 3. If This Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or
        (c), Check Whether the Person Filing is a:

        (a) |_| Broker or dealer registered under section 15 of the Act
                (15 U.S.C. 78o).

        (b) |_| Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

        (c) |_| Insurance company as defined in section 3(a)(19) of the Act
                (15 U.S.C. 78c).

        (d) |_| Investment company registered under section 8 of the Investment
                Company Act of 1940 (15 U.S.C 80a-8).

        (e) |_| An investment adviser in accordance with
                ss. 240.13d-1(b)(1)(ii)(E);

        (f) |_| An employee benefit plan or endowment fund in accordance with
                ss.240.13d-1(b)(1)(ii)(F);

        (g) |_| A parent holding company or control person in accordance with
                ss.240.13d- 1(b)(1)(ii)(G);

        (h) |_| A savings associations as defined in Section 3(b) of the
                Federal Deposit Insurance Act (12 U.S.C. 1813);

        (i) |_| A church plan that is excluded from the definition of an
                investment company under section 3(c)(14) of the Investment
                Company Act of 1940 (15 U.S.C. 80a-3);

        (j) |_| Group, in accordance with ss. 240.13d-1(b)(1)(ii)(J).

        If this statement is filed pursuant to Rule 13d-1(c),
        check this box. |_|

Item 4. Ownership

    (a) Amount beneficially owned:
        USO - 1,007,173
        RUG - 1,107,936
        RENN - 2,129,191
        Russell Cleveland - 2,129,191 (1)

    (b) Percent of class:
        USO - 6.6%
        RUG - 6.0%
        RENN - 12.3%
        Russell Cleveland - 12.3%

    (c) Number of shares as to which such person has:
        (i)   Sole power to direct the vote
              USO - 0
              RUG - 0
              RENN - 14,082
              Russell Cleveland - 14,082

        (ii)  Shared power to direct the vote
              USO - 1,007,173
              RUG - 1,107,936
              RENN - 2,115,109
              Russell Cleveland - 2,115,109

               (2)

        (iii) Sole power to dispose or direct the disposition of
              USO - 0
              RUG - 0
              RENN - 14,082
              Russell Cleveland - 14,082

        (iv)  Shared power to dispose or direct the disposition of
              USO - 1,007,173
              RUG - 1,107,936
              RENN - 2,115,109
              Russell Cleveland - 2,115,109 (3)

Item 5. Ownership of 5 Percent or Less of a Class.

        If this statement is being filed to report the fact that as of the date
        hereof the reporting person has ceased to be the  beneficial owner of
        more than 5 percent of the class of  securities, check the following |_|

Item 6. Ownership of More than 5 Percent on Behalf of Another Person.

        N/A

Item 7. Identification and Classification of the Subsidiary Which Acquired the
        Security Being Reported on by the Parent Holding Company or Control
        Person.

        N/A

Item 8. Identification and Classification of Members of the Group.

        N/A

Item 9. Notice of Dissolution of Group.

        N/A

Item 10. Certifications

         N/A


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1. The shares held by each of RENN and Russell Cleveland include the shares
   held by each of R US and USO, as well as options to purchase 14,082 shares of
   the Issuer's common stock held by RENN.


2. RENN is the investment adviser/manager to USO and R US and shares power
   pursuant to an investment advisory agreement.


3. RENN is the investment adviser/manager to USO and
   R US and shares dispository power pursuant to an investment advisory
   agreement.



Page 6 of 7 Pages


After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

                                      Renaissance US Growth Investment Trust PLC

Date: 02/14/2008                      /s/ Russell Cleveland
                                      Name:  Russell Cleveland
                                      Title: President, RENN Capital
                                             Group, Inc., Investment Adviser


                                      US Special Opportunities Trust PLC

Date: 02/14/2008                      /s/ Russell Cleveland
                                      Name:  Russell Cleveland
                                      Title: President, RENN Capital
                                             Group, Inc., Investment Manager


                                      RENN Capital Group, Inc.

Date: 02/14/2008                      /s/ Russell Cleveland
                                      Name:  Russell Cleveland
                                      Title: President


                                      Russell Cleveland

Date: 02/14/2008                      /s/ Russell Cleveland
                                      Name:  Russell Cleveland

The original statement shall be signed by each person on whose behalf the
statement is filed or his authorized representative. If the statement is signed
on behalf of a person by his authorized representative other than an executive
officer or general partner of the filing person, evidence of the
representative's authority to sign on behalf of such person shall be filed with
the statement, Provided, however, That a power of attorney for this purpose
which is already on file with the Commission may be incor porated by reference.
The name and any title of each person who signs the statement shall be typed or
printed beneath his signature.

ATTENTION: Intentional misstatements or omissions of fact constitute Federal
criminal violations (see 18 U.S.C. 1001). (Secs. 3(b), 13(d)(1), 13(d)(2),
13(d)(5),  13(d)(6), 13(g)(1), 13(g)(2), 13(g)(5), 23, 48 Stat. 882, 894, 901;
sec. 203(a),  49 Stat. 704; sec. 8, 49 Stat. 1379; sec. 10, 78 Stat. 88a; sec.
2, 82 Stat. 454;  secs. 1, 2, 84 Stat. 1497; secs. 3, 10, 18, 89 Stat. 97, 119,
155; secs. 202, 203,  91 Stat. 1494, 1498, 1499; (15 U.S.C. 78c(b), 78m(d)(1),
78m(d)(2), 78m(d)(5),  78m(d)(6), 78m(g)(1), 78m(g)(2), 78m(g)(5), 78w)) [43 FR
18499, Apr. 28, 1978,  as amended at 43 FR 55756, Nov. 29, 1978; 44 FR 2148,
Jan. 9, 1979; 44 FR 11751,  Mar. 2, 1979; 61 FR 49959, Sept. 24, 1996; 62 FR
35340, July 1, 1997; 63 FR 2867,  Jan. 16, 1998; 63 FR 15287, Mar. 31, 1998]

Page 7 of 7 Pages