IBM 3088 - Dummy questions

Gerold Pauler wrote: they were a crosspoint switch for channels. The use for them could be channel to channel, or you could also use them to reassign cabling if you had a disaster plan or emergency plan. They had the unique capability to actually function with the power off of them with the last selected configuration. I do know we tried it with the unit we had. We could switch 3880's between a 4381 and a 9221 when we needed to for testing in our case. My understanding is they were developed for airline res center use and a lot of their capability was put in for that use. There was the capability to configure them to have two switch capabilities set up in their "firmware" whatever that was, and if the power was present to them, but not necessarily any CPUs functional, you could hit a switch on the front to select between configurations directly on the 3088. In that mode you could perhaps have a large comm setup like a Res center would have connected to alternate mainframes, and on the other side you could configure up switchable dasd farms so you could switch between those if need be. I don't know of a lot of systems which would work with the shared DASD, so it had limited use on that side outside of test switching, as most applications would want to drive redundant dasd if need be. I know that Brian Knittel on this list at one time had some mainframe as does Patrick Finnegan, but Patrick may have all Escon now, and not have the interest in the 3088 parallel channel stuff anymore. Jim