SECTION 1.    Section 89A of chapter 276 of the General Laws, as appearing in the 2000 Official Edition, shall hereby be amended by inserting at the end thereof the following paragraph: --   Subject to the provisions and limitations of sections one to twenty-eight, inclusive, of chapter thirty-two, any member in service of a retirement system established under said sections, shall be credited with all service rendered by him as a deputy probation officer under this section; provided that before any retirement allowance becomes effective for him, he pays into the annuity savings fund of such system, with buyback interest as defined in said sections, in one sum, or in installments, upon such terms and conditions as the board managing such system may prescribe, an amount equal to that which would have been withheld as regular deductions from the minimum annual salary payable to a probation officer of said court during the period that such member in service or person so retired served as such deputy probation officer.