6947ch06.fm

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

Compatibility support NOT required

G5, G6, z800, or z900

 

 

OS/390

z/OS

z/OS

z/OS

z/VM

R10

1.2

1.3

1.4

 

 

 

 

 

ICF

Compatibility support required on all z990

logical partitions

z990

 

 

 

 

OS/390

z/OS

z/OS

z/OS

 

R10

V1R2

V1R3

V1R4

z/VM

Compat

Compat

Compat

Compat

Compat

 

 

 

 

ICF

 

 

 

 

LPAR id

 

 

 

 

<= F

CSS 0

z/OS 1.1 is not supported in the same Sysplex if any participating system is on a z990 Sysplex supports systems on z990 and non-z990 processors, with and without the compatibility support

CF

If z990 CF LPAR id is equal or less than x' F, then compatibility code is not required on OS partitions running on non-z990 processor

CF partition can be in any LCSS

OS partitions on z990 must be in LCSS 0 and have LPAR id equal or less than x'F'

Figure 6-1 Conditions where compatibility maintenance is not required

Figure 6-2 shows the situation where the compatibility support is required.

Compatibility support required on all

Compatibility support required on all

non-z990 OS logical partitions

z990 OS logical partitions

G5, G6, z800, or z900

 

OS/390

z/OS

z/OS

z/OS

z/VM

R10

1.2

1.2

1.2

Compat

Compat

Compat Compat

Compat

ICF

 

 

 

 

z990

 

 

 

 

OS/390

z/OS

z/OS

z/OS

z/VM

R10

1.2

1.3

1.4

Compat

Compat

Compat

Compat Compat

ICF

 

 

 

 

 

 

 

 

LPAR id

 

 

 

 

> F

 

 

 

CSS 0

 

If z990 CF LPAR id is greater than x'F'

CF

OS partitions on z990 must be in LCSS 0

 

then compatibility support is required on

 

and have LPAR id equal to or less than x'F'

all non-z990 system images participating

 

CF partition can be in any LCSS

in the SYSPLEX

 

 

Figure 6-2 Conditions where compatibility maintenance is required

Compatibility support restrictions

Compatibility support does not allow you to make full use of all the capabilities of the z990. Some restrictions that apply when running in this mode are:

￿z/OS with Compatibility support must be IPLed in a partition defined to LCSS 0. If it is IPLd in a partition in another LCSS, it will terminate with a 07C-01 wait state.

136IBM eServer zSeries 990 Technical Guide

Page 149 Page 151
Page 150
Image 150
IBM manual Compatibility support restrictions, Z990
Page 149 Page 151

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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