2008-now   Berkeley Quantitative, LLC, Chairman

1998-now   Space Computer Corporation

1992-now   A K Peters, Ltd

1984-1990 + 1995-2002  Cylink (NSDQ: CYLK; now Safenet)
      Audit Committee

1982-1993 IC Designs (became Cypress Timing Technology)

1989-1991 Axcom Trading Advisors, President (now Renaissance Technologies)

1986-1989 Kodak Federal Systems Division

1974-1989 Cyclotomics, President, (became Kodak Berkeley Research)