In Hera and Sung (1989), it is shown that for a SISO digital control system, sensitivity improvement is possible by a two-delay output controller. In this paper, it is shown that the result is restricted to a limited class of SISO plants only. To help circumvent the problem, the author provides an approach towards sensitivity improvement using a generalized sampled-data hold function (GSHF) based two-delay output controller. The proposed controller is able to attain the infimum of the H/sup /spl infin//-norm sensitivity optimization problem for a two-delay digital control system irrespective of whether the continuous-time plant has zeros at the origin or not. >