All, The enclosed document describes an addition to BIRD 122 that allows the IC Vendor to define an ISS template to be used when generating the the Impulse Response of a channel. I accept that the following two questions need to be clarified, but they are the same question whether the ISS subckt is specified using this method, or the method proposed by Arpad in BIRDS 116-118. 1. When describing a driver, what's the exact nature of the signal delivered to the die ports? 2. When describing a receiver, how, exactly, are the die-side ports loaded and measured? Walter Walter Katz wkatz@xxxxxxxxxx Phone 303.449-2308 Mobile 303.883-2120