6947ch02.fm

Draft Document for Review April 7, 2004 6:15 pm

A frame

As shown in Figure 2-9, the main components in the A-frame are:

1.Two Internal Battery Features (IBFs)

The optional Internal Battery Feature provides the function of a local uninterrupted power source.

The IBF further enhances the robustness of the power design, increasing Power Line Disturbance immunity. It provides battery power to preserve processor data in case of a loss of power on both of the AC feeders from the utility company. The IBF can hold power briefly over a “brownout”, or for orderly shutdown in case of a longer outage. The IBF provides up to 20 minutes of full power, depending on I/O configuration.

2.One or two Modular Refrigeration Units (MRUs) that are air-cooled by their own internal cooling fans.

3.The CEC cage, containing up to four books, each with two insulated refrigeration lines to an MRU.

4.I/O Cage 1, which can house all supported types of channel cards. An I/O cage accommodates up to 420 ESCON channels or up to 40 channels in the absence of any other card.

5.Air-moving devices (AMD) providing N+1 cooling for the MBAs, memory, and DCAs.

Z frame

As shown in Figure 2-9, the main components in the Z-frame are:

1.Two Internal Battery Features (IBFs) (see IBF in A frame for more information).

2.The Bulk Power Assemblies (BPAs).

3.I/O cage 2 (bottom), and I/O cage 3 (top).Note that both I/O cages are the same as the one in the A frame, and can house all supported types of channel card.

The Z frame holds: no cages; only the bottom cage (I/O cage 2); or both the bottom and top I/O cages (I/O cage 2 and I/O cage 3).

4.The Service Element (SE) tray, which is located in front of I/O cage 2, contains the two SEs.

I/O cages

There are 12 STI buses per book to transfer data, with a bi-directional bandwidth of

2.0GB/sec each. An STI is driven off an MBA. There are three MBAs per book, each driving four STIs, providing an aggregated bandwidth of 24 GB/sec per book.

The STIs connect to I/O cages that may contain a variety of channel, coupling link, OSA-Express and Cryptographic feature cards:

￿ESCON channels (16 port cards).

￿FICON channels (FICON or FCP modes, 2 port cards).

￿ISC-3 links (up to 4 coupling links, two links per daughter card (ISC-D). Two daughter cards plug into one mother card (ISC-M).

￿Integrated Cluster Bus (ICB) channels, both ICB-2 (333 MB/sec) and ICB-3 (1 GB/sec). Both ICB-2 and ICB-3 (compatibility mode ICBs) require an STI extender card in the I/O cage.

￿OSA-Express channels

–OSA-E Gb Ethernet

–Fast Ethernet

34IBM eServer zSeries 990 Technical Guide

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IBM 990 manual Cages, Frame
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990 specifications

The IBM 990 series, often referred to in the context of IBM's pioneering efforts in the realm of mainframe computing, represents a unique chapter in the history of information technology. Introduced in the late 1960s, the IBM 990 series was designed as a powerful tool for enterprise-level data processing and scientific calculations, showcasing the company's commitment to advancing computing capabilities.

One of the main features of the IBM 990 was its architecture, which was built to support a wide range of applications, from business processing to complex scientific computations. The system employed a 32-bit word length, which was advanced for its time, allowing for more flexible and efficient data handling. CPUs in the IBM 990 series supported multiple instructions per cycle, which contributed significantly to the overall efficiency and processing power of the machines.

The technology behind the IBM 990 was also notable for its use of solid-state technology. This provided a shift away from vacuum tube systems that were prevalent in earlier computing systems, enhancing the reliability and longevity of the hardware. The IBM 990 series utilized core memory, which was faster and more reliable than the magnetic drum memory systems that had been standard up to that point.

Another defining characteristic of the IBM 990 was its extensibility. Organizations could configure the machine to suit their specific needs by adding memory, storage, and peripheral devices as required. This modular approach facilitated the growth of systems alongside the technological and operational demands of the business environments they served.

In terms of software, the IBM 990 series was compatible with a variety of operating systems and programming environments, including FORTRAN and COBOL, enabling users to access a broader array of applications. This versatility was a significant advantage, making the IBM 990 an appealing choice for educational institutions, research facilities, and enterprises alike.

Moreover, the IBM 990 was engineered to support multiprocessing, which allowed multiple processes to run simultaneously, further increasing its effectiveness in tackling complex computing tasks.

In summary, the IBM 990 series represents a significant advancement in computing technology during the late 20th century. With a robust architecture, versatile configuration options, and a focus on solid-state technology, the IBM 990 facilitated substantial improvements in data processing capabilities, making it a cornerstone for many businesses and academic institutions of its time. Its impact can still be seen today in the continued evolution of mainframe computing.
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