<In RT-11, full MSCP support post-dates even 5.1. 5.1 works with RQDX1/2, define full? <but not RQDX3, for example; because whoever wrote the DU: handler ignored Dont tell mine RT11 V5.01c system then as the RQDX3 runs just fine. To the best of my knowlege RQDXn are interchangeable (I have done that) with one exception... the drive must be formatted for the RQDX3 as it's apparently different from the 1/2. Allison