Exhibit 3.a
 FILEDARTICLES OF INCORPORATION
    
    In the Office of theOF 
INTERPHASE CORPORATION
    
    Secretary of State of TexasMAR 07 1977Lorna SalzmanDeputy Director, Corporation Division




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WILLIS E. KUHN, II
    
    28th Floor
Republic National Bank Tower
Dallas, Texas 75201MICHAEL E. COPE
    
    619 Newberry
Richardson, Texas 75080TOM S. THAWLEY
    
    2024 Chestnut
Carrollton, Texas 75007
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RODNEY D. MOORE
    
    28th Floor, Republic National Bank Tower
Dallas, Texas 75201WILLIS E. KUHN, II
    
    28th Floor, Republic National Bank Tower
Dallas, Texas 75201EDWARD A. PETERSON
    
    28th Floor, Republic National Bank Tower
Dallas, Texas 75201
 nd
 /s/ Rodney D. Moore

RODNEY D. MOORE/s/ Willis E. Kuhn, II

WILLIS E. KUHN, II/s/ Edward A. Peterson

EDWARD A. PETERSON
 THE STATE OF TEXAS
    
    §COUNTY OF DALLAS
    
    §
  /s/ Marsha EubankNotary Public in and forDallas County, Texas
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FILEDARTICLES OF AMENDMENT
    
    In the Office of theTO THE
    
    Secretary of State of TexasARTICLES OF INCORPORATION
    
    JUN 26 1981CLERK II HCorporation Division




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INTERPHASE CORPORATIONBy:
    
    /s/ Michael Cope

Michael Cope, PresidentBy:
    
    /s/ Samuel T. Thawley

Samuel T. Thawley, Secretary




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STATE OF TEXAS
    
    §COUNTY OF DALLAS
    
    §
   (Seal)
    
    /s/ Suzan E. Fenner

Notary Public in and forthe State of TexasMy commission expires: 2-2-85
 STATE OF TEXAS
    
    §COUNTY OF DALLAS
    
    §
   (Seal)
    
    /s/ Suzan E. Fenner

Notary Public in and forthe State of TexasMy commission expires: 2-2-85




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FILEDARTICLES OF AMENDMENT TO THE ARTICLES OF INCORPORATION
    
    In the Office of theOF INTERPHASE CORPORATION
    
    Secretary of State of TexasMAR 28 1988Corporations Section




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INTERPHASE CORPORATIONBy:
    
    /s/ Michael E. Cope

Michael E. CopeIts: President
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ARTICLES OF AMENDMENT
    
    FILEDTO THE ARTICLES OF INCORPORATION
    
    In the Office of theOF INTERPHASE CORPORATION
    
    Secretary of State of TexasAPR 19 1994Corporations Section
      (a)
    
    a breach of the directors duty
of loyalty to the corporation or its shareholders;(b)
    
    an act or omission not in good
faith that constitutes a breach of duty of the director
to the corporation or an act or omission that involves
intentional misconduct or a knowing violation of the
law;(c)
    
    a transaction from which the
director received an improper benefit, whether or not
the benefit resulted from an action taken with the scope
of the directors office; or(d)
    
    an act or omission for which the
liability of the director is expressly provided for by
an applicable statute.




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INTERPHASE CORPORATIONBy:
    
    /s/ Michael E. Cope

Michael E. Cope,Chief Executive Officer
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ARTICLES OF AMENDMENT
    
    FILEDTO THE ARTICLES OF INCORPORATION
    
    In the Office of theOF
    
    Secretary of State of TexasINTERPHASE CORPORATION
    
    MAY 03
2000Corporations Section




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INTERPHASE CORPORATIONBy:
    
    /s/ Gregory B. Kalush

Gregory B. Kalush, President
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