Instead of TAIT circuit, try to use externally powered DL4YHF circuit.
i can send you an artwork for homebrewing a pcb.
it needs external regulated 12V or unregulated 15 or 16V DC as input.
if 12V is given , you need not mount the regulator and associated components on the programmer board.
This design helps Vpp first facility as 5V is derived from 12V. you might need that facility of Vpp first in 16F628A under a specific condition of Internal clock and Mclr off.