Using z/OS Assembler

Virtual Classroom Environment dates - click to book!

UK Start Times

What do I need?

• webcam
• headphones with microphone
• sufficient bandwidth, at least 1.5 Mb/s in each direction.

What you will learn

On successful completion of this course you will be able to:

• describe the format of machine instructions
• demonstrate an understanding of addressing and base registers
• explain how control sections and dummy sections are used
• describe how to use a working set of machine instructions
• explain the difference between machine and Assembler instructions
• define constants and storage
• code instructions which will perform: arithmetic, data manipulation, program control, file handling and table handling
• explain how condition codes and masks are used
• read dumps
• explain how module linkage works
• use BASSM and BSM instructions
• understand the concepts of 31 & 64 bit addressing and its effects on existing machine instructions.

Who Should Attend

Systems Programmers who will need to 'read, mend and modify' Assembler programs.

Prerequisites

Experience of using z/OS, including using TSO/ISPF and submitting batch jobs. For programmers it is an advantage to have a good knowledge of either a high level (e.g. COBOL or PL/I) or a procedural language (e.g. CLISTs or REXX).

Duration

5 days

Fee (per attendee)

£2350 (ex VAT)

This includes free online 24/7 access to course notes.

Hard copy course notes are available on request from rsmshop@rsm.co.uk

at £50.00 plus carriage per set.

Course Code

AS

Contents

Introduction to Assembler Programs

Programming languages; The Assembly process; The Linking process; Assembler program structure; Assembler directives; Macro instructions; Assembler instructions; Instruction formats; Storage locations and addresses; Machine instructions; Symbolic statements; Syntax; Statement format; The Operation & operand fields; Hexadecimal - a shorthand form of binary; Character Assignments.

Handling Character Data

Defining fields; Define Storage & Constants; Examples of DS & DC; Defining areas with zero repetition; Move instructions; Move Long instruction; Literals, constants and immediate data; Dummy Sections (DSECTs); Equates (EQU).

Comparisons, Branching & Structure

Comparison instructions; Branching Instructions; Branch Mnemonics (BC instruction); BCT/BCTR for looping; Program skeleton; Executable code; The location counter; Addressing; Register convention; Save area chaining; Relative addressing; Indexing; Declarative part; Instructions to the Assembler; Subroutines; Branch and Link Instructions; BASSM & BSM instructions; Branch Register instruction; BXH / BXLE For looping; Execute; Program linkage with BAKR; Linkage Stack; Linkage Stack operations - PICs

Binary Instructions

Signed binary arithmetic instructions; Types of Binary Instruction; Loading and Storing; Load and Store Instructions; The Binary Add Instructions; Binary Subtraction Instructions; Binary comparisons; Convert to Binary; Convert to Decimal; Multiplying Fullwords; Binary Division; Bit shifting instructions.

Macros & Input/Output

Macros; File handling; Building a control block; The DCB; DCB tied to File; The DCB explained; DCB parameters explained; The OPEN macro; The GET macro; The PUT macro; The CLOSE macro; Printed output data sets; Clearing the print line.

Packed Decimal Arithmetic

Summary of 'Decimal Manipulating Instructions'; Summary of decimal instructions; Packed Decimal; Add Packed instruction; SP and ZAP instructions; Pack and Unpack instructions; Move Zone Instruction; Move Numeric Instruction; Decimal Condition Codes; Editing Packed Decimal Data; Constructing patterns; EDIT example; EDMK instruction; Packed Decimal multiplication; Packed Decimal division.

Translations and Bit Manipulations

Summary of bit manipulating instructions; 'OR'ing; 'AND'ing; Exclusive 'OR'ing; Testing the bits; Translate instruction; Translation Tables + 'ORG'; TRT- Translate and Test instruction.

MVS Error Reporting, Dumps & Binder

System error reporting; MVS dumps; Stand-Alone Dump (SADUMP); SVC Dumps; User ABEND Dumps; Generating a User ABEND Dump; System Generated ABEND dump; Snap dumps; Symptom dumps; Program Interruption Codes (PICs); Explanations of the Assembler program listings; The External Symbol Dictionary (ESD); The Source and Object program listing; The Relocation Dictionary; The Symbol and Literal cross-reference (HLASM); The Diagnostic Cross Reference and Summary (HLASM); Options Summary (HLASM); Dump labs.

24, 31 & 64 Bit Programming

Impact of 31-bit addressing; Addressing Memory - when and where?; Extended Addressing; 31-bit Virtual Addressing; Dynamic Address Translation; Addressing-mode control; Instruction differences; ; different addressing; Setting the mode when branching; Branch-And-Save-and-Set-Mode (BASSM); Branch-and-Set-Mode (BSM); Coding examples; The z/Architecture differences; z/Architecture - the bottom line; Tri-modal addressing mode; Memory boundaries; Registers in a z/Architecture machine; 64-bit registers and instructions; z/Architecture PSW; The 64-bit virtual address; Changing to 64-bit mode; Setting the mode when branching; Indicating 64-bit mode in pointers; Branch-And-Save-and-Set-Mode (BASSM); A z/OS address space; Characteristics of Memory Objects.