These computers run an MVS-ESA operating system, and use JES3 as the job scheduler. Up to 256 of each type DASD may be connected to the appropriate storage control unit, which in turn makes the storage devices available to the mainframes. Other data storage devices include the 3480 cartridge magnetic tapes, with an estimated 30,000 tapes in the library. There are twenty-four 3480 type cartridge tape drives in place to read these tapes. In addition, two Model 4400 Storage Tek Cartridge Tape Silos have been installed and house 5,500 cartridge tapes each.
Robotic arms handle the load and unload of tapes from the drives.
In addition to the mainframes, several mid-range computer systems are involved in the NS computer system. There are a large number of Unix-based systems at Norfolk Southern that support various OLTP applications as well as DSS environments. Network Devices People interact with the computer through a 3270 type terminal or a PC with some type of 3270 emulation capability. Most of these communication lines are considered remote, and do not provide the response time received by devices connected to the computer in the Atlanta office building. The Norfolk Southern network consists of various types of hardware, software and operating systems.