 These heads enabled operation of both the 1” and 2” machines in Britain long after US spares supply ceased.In the early 1970s IVC entered into an arrangement with UK company Quantel for the design of a Digital Time Base Corrector (TBC) to enable the output of the 800 series VTRs to be synchronous with the studio drives, hence enabling mixing and switching as if the VTR was another studio live source.The result was the IVC2000 in NTSC, and the IVC2001 in PAL and SECAM.