The Public Records of the Colony of Connecticut, Prior to Union with New Haven Colony is a 15 volume set of records available for free at Internet Archive. Links to each volume are below:

Volume 1– The Public Records of the Colony of Connecticut, Prior to Union with New Haven Colony, April 1636-May 1665

Volume 2- The Public Records of the Colony of Connecticut, 1665-1678, with the Journal of the Council of War, 1675-1678

Volume 3- The Public Records of the Colony of Connecticut, May 1678-June 1689

Volume 4-The Public Records of the Colony of Connecticut, August 1689-May 1706

Volume 5-The Public Records of the Colony of Connecticut, October 1706-October 1716

Volume 6-The Public Records of the Colony of Connecticut, May 1717-April 1726

Volume 7-The Public Records of the Colony of Connecticut, May 1726-May 1735

Volume 8-The Public Records of the Colony of Connecticut, October 1735-October 1743

Volume 9-The Public Records of the Colony of Connecticut, May 1744-November 1750

Volume 10-The Public Records of the Colony of Connecticut, May 1751-February 1757

Volume 11-The Public Records of the Colony of Connecticut, May 1757-March 1762

Volume 12-The Public Records of the Colony of Connecticut, May 1762-October 1767

Volume 13-The Public Records of the Colony of Connecticut, May 1768-May 1772

Volume 14-The Public Records of the Colony of Connecticut, October 1772-April 1775

Volume 15-The Public Records of the Colony of Connecticut, May 1775-October 1776 and an appendix containing some council proceedings, 1663-1710