|An IBM 9370 system in an office environment with rack mounted CPU and disks.|
In 1986, IBM announced the IBM 9370 family of mid-sized systems. The 9370 was designed to operate in an office environment and introduced a new form factor for mainframes. The 9370 was packaged for standard 19-inch racks. Four models were included in the initial announcement. Main memory ranged from 4 to 16 MB. In addition to the CPU itself, new rack mounted FBA disk (IBM 9332 and 9335) and tape (IBM 9347) products were introduced as well.
Slowly and deliberately, DOS/VSE transformed into VSE/Systems Package (VSE/SP). VSE/SP consisted of an integrated, pre-packaged VSE system. The metamorphosis began with the ‘SIPO’ concept. SIPO originated in IBM Canada and was a visionary attempt to provide a pre-configured system. SSX/VSE took integration even further and added a set of systems management dialogs. SSX ultimately proved to be too rigid for most customers. However, the basic approach proved sound. VSE/SP V1 and V2 refined the concept and made it more generally acceptable. The Fast Service Upgrade (FSU) process made release-to-release migration simpler.
By 1987, VSE/SP V3 implemented a packaging concept that remains visible to this day in z/VSE. The structure consists of base and optional products. The ‘base’ is an integrated package containing key, commonly used products. It is designed, developed, tested, delivered, and serviced as an integrated whole. ‘Optional’ products are coordinated so that the list contains the correct level of each product. Installation procedures and dialogs are provided. Following an order, base and optional products are stacked together on the delivery media. Service is coordinated for both base and optional products and appropriate prerequisite and corequisite levels and service are identified.
The goal of the packaging was a system with better quality and more stability, and one that was easier to install and service than before. VSE customers approved and the structure survives today. For example, z/VSE V3.1 base components include the supervisor, dialogs, POWER, VSAM, ICCF, LE, utilities, VSE connectors, HLASM, CICS TS VSE/ESA, ACF/VTAM, TCP/IP for VSE/ESA, DITTO, and DB2. Indeed, MVS adopted a similar approach to transform itself into OS/390 (now z/OS).
VSE/SP V3 also offered major enhancements, including some first introduced in VSE/SP V2. For example, VSE/SP V3 included a new librarian, conditional JCL, and Virtual Address Extensions (VAE). VAE was an attempt to extend the capacity of VSE. It provided up to 3 address spaces, each with no more that 16 MB. Each address space contained all common and shared space. During this period, IBM moved toward a capacity-based software pricing model.
|Compact tape cartridges begin to replace traditional reel-to-reel tapes.|
In 1987, an imaginary VSE/SP V3 customer might have an IBM 9370 Model 60 with 8 MB of main memory, 6-8 IBM 9332 (185 MB per actuator) disk drives, and a 9347 tape unit.
Tape processing declined. Tapes were largely used for backup, archiving, and data interchange. With the IBM 3480, self-contained, easy-to-handle, cartridges (‘square’ tape) replaced traditional reel-to-reel (‘round’ tape) media.
During the 1980s, some customer applications began to bump up against the limitations of the S/370 24-bit (16 MB) architecture. S/370-XA (eXtended Architecture) extensions added 31-bit (2GB) real and virtual addressing in response to customer needs. Because VSE/SP did not implement 370-XA architecture, it began to look as if VSE might be left behind.
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