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

6947ch04.fm

Channel spanning is supported for internal links (HiperSockets, and Internal Coupling (IC) links), and for some external links (FICON Express channels, OSA-Express, and coupling links). For a complete list of supported spanned channels, see Table 3-8, “Spanned and shared channels” on page 91.

Note: Spanning of ESCON channels, FICON converter (FCV) channels and receiver coupling links are not supported.

In Figure 4-4, CHPID 04 is spanned to LCSS0 and LCSS1. Since it is not an external channel link, there is no PCHID assigned. CHPID 06 is an external spanned channel and has a PCHID assigned.

Partition Partition

 

Partition Partition Partition

Partition

Partition

 

Partition

 

1

 

2

 

14

15

16

17

18

 

30

 

 

 

 

 

LCSS0

 

 

 

 

LCSS1

 

 

 

MIF-1 MIF-2

MIF-F

 

 

 

MIF-1 MIF-2

MIF-3

MIF-F

CHPID CHPID CHPID

CHPID

CHPID

CHPID

CHPID

CHPID CHPID

CHPID

CHPID CHPID

00

01

02

03

FF

00

01

05

22

FF

Share

04

 

06

Share

 

 

 

 

 

 

 

 

 

PCHID PCHID PCHID PCHID

PCHID

SPAN

SPAN

PCHID PCHID PCHID PCHID PCHID

10B

10C

10D

20E

20A

 

 

 

145

146

147

158

159

 

 

 

 

 

 

PCHID

 

 

 

 

 

 

 

 

 

 

 

120

 

 

 

 

 

Figure 4-4 z990 CSS - two Logical Channel Subsystems with channel spanning

4.2 LCSS configuration management

Tools are provided to maintain and optimize the I/O configuration of a z990.

IBM Configurator for e-business (e-Config)

The e-Config tool is available to your IBM representative. It is used to configure new configurations or upgrades of existing configuration, and maintains installed features of those configurations.

Hardware Configuration Dialog (HCD)

HCD supplies an interactive dialog to generate your I/O definition file (IODF) and subsequently your Input/Output Configuration Data Set (IOCDS). It is strongly recommended that HCDor HCM be used to generate your I/O configuration, as opposed to writing your own IOCP. The validation checking that HCD performs as you enter data helps eliminate errors before you implement your I/O configuration.

Chapter 4. Channel Subsystem 115

Page 129
Image 129
IBM 990 manual Lcss configuration management, IBM Configurator for e-business e-Config, Hardware Configuration Dialog HCD

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.