No, the OS did the drive assignments, and then prompted the operator to do the mount of the appropriate VolSer on a given drive. The label was of course checked as part of the OS/360 open process, and if there was a label, and it was not expired, one could not write over it, or, whether reading or writing, that the label matched the requested DSN.
(Remember that OS/360 never heard of the 3480 tapes and their autoloaders - things presumably changed then, along with tape library management software, but by then I had moved on from mainframes, and what little I did with them didn't involve tape). The operators I worked with almost never mismounted a tape. JRJ On 8/9/2015 1:13 PM, Chuck Guzis wrote: > On 08/09/2015 10:45 AM, Jay Jaeger wrote: > >> Seems dangerous to me: duplicate data set names on different tapes would >> confuse it (plus, if the DSN is long, the entire DSN does not actually >> appear in the tape label). I worked with OS/360 and MVS in my career >> and we never did anything like that with it. > > So you'd trust your job to a 9-5 operator who really didn't care what > the machine was doing to make tape assignments? > > Wow. Good thing that tapes have write-enable rings. > > --Chuck > >