30 ILCS 390/9
To provide for the manner of repayment of the Bonds, the Governor shall include an appropriation in each annual State Budget of monies in such amount as shall be necessary and sufficient, for the period covered by such budget, to pay the interest, as it shall accrue, on all Bonds issued under this Act and also to pay and discharge the principal of the Bonds as shall by their terms fall due during such period. A separate fund in the State Treasury called the "School Construction Bond Retirement and Interest Fund" is hereby created. The General Assembly shall make appropriations to pay the principal of and interest on the Bonds from the School Construction Bond Retirement and Interest Fund. If for any reason the General Assembly fails to make appropriations of amounts sufficient for the State to pay the principal of and interest on the Bonds as the same shall by the terms of the Bonds become due, this Act shall constitute an irrevocable and continuing appropriation of all amounts necessary for that purpose, and the irrevocable and continuing authority for and direction to the Comptroller and to the Treasurer of the State to make the necessary transfers out of and disbursements from the revenues and funds of the State available for that purpose.
30 ILCS 390/9