6947ch03.fm

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

output ports to support the ICB-2 connections. The STI-2 card converts the 2.0 GByte/sec input into two 333 MB/sec ICB-2s. One ICB-2 feature is required for each end of the link. Each ICB-2 link at the z990 end has a PCHID number. ICB-2 only support connection to 9672 G5/G6 servers.

The ICB-2 cable (feature code 0226) is a unique 10 meter (33 feet) 333 MB copper cable to be used with ICB-2 links. Existing 10 meter 333 MB ICB-2 cables can be reused.

ICB-2 cables (feature code 0226) will be automatically ordered to match the quantity of ICB-2s (feature code 0992) on order. Order one cable per connection, not per feature. The quantity of ICB cables can be reduced, but cannot exceed the quantity of ICB features on order.

z990 ICB links summary

Table 3-12is showing a summary of all z990 Integrated Cluster Bus (ICB) link types, including some of their characteristics.

Table 3-12 z990 ICB links summary

ICB link type

Feature

IOCP definition

Bandwidth

Intended

Maximum

 

code

 

 

attachment

cable length

 

 

 

 

 

 

ICB-4

3393

CBP

2 GB/s

z990, z890

10 meters

 

 

 

 

 

 

ICB-3

0993

CBP

1 GB/s

z900, z800

10 meters

 

 

 

 

 

 

ICB-2

0992

CBS, CBR

333 MB/s

9672 G5/G6 only

10 meters

 

 

 

 

 

 

IC links

IC links are used when an ICF logical partition is on the same CPC as other system images participating in the sysplex. An IC link is the fastest Coupling link, using just memory-to- memory data transfers. IC links do not have PCHID number, but do require CHPIDs.

IC links require ICP channel path definition at the OS/390 or z/OS and the CF end of a channel connection to operate in peer mode. They are always defined and connected in pairs.

3.4.6 External Time Reference (ETR) feature

The External Time Reference (ETR), feature code 6154, is an optional z990 feature.

Each ETR feature consists of one ETR card and each card has one port. When a quantity of one is ordered, two features are shipped. The two ETR features are automatically ordered if any coupling link feature (ISC-3, ICB-2, ICB-3 or ICB-4) is ordered.

These cards provide attachment to the Sysplex Timer in the CPC cage. Each ETR card should connect to a different 9037 Sysplex Timer in an Expanded Availability configuration. Each feature has a single port supporting an MT-RJ fiber optic connector to provide the capability to attach to a Sysplex Timer Unit. The two ETR cards are supported in one CEC cage card slot in the rear and provide attachment to a 9037 Sysplex Timer; it can be either a 9037 Model 11 or 9037 Model 2. The 9037 Sysplex Timer provides the synchronization for the Time-of-Day (TOD) clocks of multiple CPCs, and thereby allows events started by different CPCs to be properly sequenced in time. When multiple CPCs update the same database and database reconstruction is necessary, all updates are required to be time-stamped in proper sequence.

1Note that 9037-1 goes End of Service on Dec. 31, 2003.

106IBM eServer zSeries 990 Technical Guide

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IBM manual External Time Reference ETR feature, IC links, Z990 ICB links summary
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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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