WRITE Macro

 

 

 

 

KEY

 

 

VSE

WRITE

filename

,

ID

 

 

 

 

(1)

 

RZERO

 

 

 

 

 

 

AFTER

 

 

 

 

 

 

AFTER,EOF

 

 

 

 

 

 

 

MVS

WRITE

decbname,type,

dcbaddress

,

area address,

 

 

 

 

(2-12)

 

(2-12)

 

 

length

 

key address

 

′ S′

 

 

 

 

 

 

 

(2-12)

,

(2-12)

,

block address

 

 

′ S′

 

′ S′

 

(2-12)

 

 

 

 

0

 

 

 

 

 

 

 

 

 

Notes:

1.TYPE = DA, DAF, DI, DIF, DIX, DK, DKF, or DKX.

2.S- system supplies the operand if you specify S′.

3.If the key is not written or used as a search argument, zero is specified instead of keyaddress.

CNTRL Macro

There is no equivalent in MVS BDAM to the VSE CNTRL macro. The MVS CNTRL macro does not support DASD devices.

WAITF, OPEN and CLOSE Macros

VSE

WAITF

 

filename

 

 

 

 

 

(r1)

 

 

 

 

 

MVS

WAIT

number of events,

ECB = address

 

 

 

 

ECBLIST = address

 

CHECK

dcbaddress

,DSORG = IS

 

 

 

(1-12)

 

ALL

 

 

 

 

 

 

 

 

 

 

 

VSE

OPEN(R)

filename

,...

 

 

 

(r1)

 

 

 

 

 

 

 

 

 

MVS

OPEN

dcbaddress

 

INPUT

 

 

 

(2-12)

,

OUTPUT

 

 

 

 

 

UPDAT

 

 

 

 

 

 

 

 

 

 

 

 

 

VSE

CLOSE(R)

filename

 

 

 

 

 

(r1l)

 

 

 

 

 

 

 

 

 

MVS

CLOSE

dcbaddress

,

FREE

,...

 

 

(2-12)

 

DISP

 

 

 

 

 

 

 

Notes:

1.DISP is assumed when no positioning option is specified in the CLOSE macro. The volume is then positioned according to the position implied by the DISP parameter of the DD statement.

2.Any number of dcbaddresses may be specified in the OPEN and CLOSE macros.

314VSE to OS/390 Migration Workbook

Page 338
Image 338
IBM OS/390 manual Write Macro, WAITF, Open and Close Macros

OS/390 specifications

IBM OS/390, a versatile operating system, was a cornerstone in enterprise environments and played a pivotal role in mainframe computing. Released in the mid-1990s, OS/390 combined the strengths of IBM's MVS (Multiple Virtual Storage) with new features and enhancements, targeting scalability, reliability, and performance in demanding business applications.

One of the key features of OS/390 was its robust support for multiple users and processes. The system allowed thousands of concurrent users to access applications and data, ensuring high availability and minimizing downtime—a critical requirement for many large organizations. This scalability was supported through various enhancements in memory management and processor scheduling, enabling optimal resource allocation across diverse workloads.

OS/390 was known for its superior workload management capabilities. The Workload Manager (WLM) component allowed administrators to define service policies, specifying how system resources would be allocated according to the priority of tasks. This ensured that critical business processes received the necessary resources while less critical tasks were managed more flexibly.

Another significant characteristic of OS/390 was its commitment to security. The operating system provided comprehensive security features, including user authentication, data encryption, and auditing capabilities. This focus on security was vital for organizations handling sensitive data, ensuring compliance with regulations and safeguarding against unauthorized access.

OS/390 also supported advanced technologies that facilitated integration and development. The system included features like the IBM CICS (Customer Information Control System) for transaction processing and IMS (Information Management System) for database management. These technologies allowed organizations to build robust, high-performance applications tailored to specific business needs.

The ease of network integration was another strength of OS/390. With the advent of the Internet and global connectivity, OS/390 systems could easily interface with various network protocols, enabling businesses to operate in a connected world. This inclusion paved the way for many organizations to expand their capabilities and offer new services, driving digital transformation.

In conclusion, IBM OS/390 represented a significant advancement in mainframe technology, combining scalability, security, and robust workload management. Its rich feature set and support for critical enterprise applications solidified its role as a vital component of many organizations' IT infrastructures, ensuring they could meet their operational challenges head-on while supporting future growth. As technology continues to evolve, the legacy of OS/390 remains influential in the realm of computing.