Visão Geral

O Curso Mainframe Assembler fornece uma introdução à linguagem Assembler de mainframe. O Curso Mainframe Assembler é projetado para desenvolver as habilidades adequadas para escrever e/ou manter programas e rotinas escritas em Linguagem Assembler. A ênfase é colocada no aprimoramento de habilidades na resolução de problemas por meio de análise de interrupção de verificação de programa e leitura de dump.

Objetivo

Ao participar do Curso Mainframe Assembler, os participantes aprenderão a:

• Reconhecer características arquitetônicas, como formatos de instruções, representação de dados, endereçamento de armazenamento e assim por diante, que são importantes para a análise de programas
• Identifique o ponto de interrupção do programa, usando o dump do sistema formatado e elementos de informações como a palavra de status do programa (PSW), o código de comprimento de instrução (ILC), o(s) registro(s) base(s) do programa e assim por diante
• Identificar padrões apropriados para programas assembler em termos de organização de programas, convenções de registro, práticas de codificação, documentação e assim por diante
• Codifique e depure programas em linguagem assembler que:
• Em conformidade com as convenções de ligação padrão usando o encadeamento de áreas salvas
• Definir e usar vários tipos de definições de dados, incluindo binário de ponto fixo, caractere, hexadecimal e decimal compactado
• Empregue macros padrão como CALL, SAVE, RETURN
• Use várias instruções da linguagem Assembler, como CSECT, EQU, COPY, END
• Use formas de notação simbólica e explícita para instruções
• Use literais de dados adequadamente e explique o uso de LTORG para direcionar o posicionamento do conjunto literal
• Crie e use padrões apropriados para instruções de EDIÇÃO

Publico Alvo

O Curso Mainframe Assembler é ideal para programadores de aplicativos e/ou programadores de sistemas iniciantes que codificam, mantêm e/ou depuram programas ou sub-rotinas de suporte a aplicativos escritos em linguagem Assembler.

Pre-Requisitos

• Experiência com Mainframes.

Materiais

Conteúdo Programatico

Introduction to Assembler Language

1. Types of Assembler Statements
2. Number systems
3. Decimal number system
4. Hexadecimal number system
5. Conversion Formats
6. Addition of Binary And Hexadecimal Numbers
7. Bytes, Word And Halfword
8. Representation of Negative Binary Numbers
9. How Numbers are Stored in Different Formats
10. General Assembly Process

JCL for running an Assembly language program

1. Using IBM Supplied Procedures
2. System Library Names and their Usage
3. Assembly time Options

Assembly Language Format

1. (Label, Operation Code, Operand Fields, Comments, Continuation Column, Sequence Numbers)
2. Registers, Memory and its Usage
3. YREGS Macro
4. Defining Storage in Memory (DC and DS instructions)
5. Load (L instruction)
6. Add and Subtract (A and S instructions)
7. Store (ST instruction)
8. Halting Execution
9. Literal constants – F, H, C, P, D, A, V, X, B

Addressing

1. Base register, Index register, Displacement
2. Types of Instructions - RX, RR, RS, SS, SI
3. Two byte, four byte and six byte instruction formats
4. RR Type Instruction (AR, SR, MR, DR, LR instructions)
5. RX Type Instruction (A,S,M,D,L,ST instructions)
6. Effective Addresses
7. BALR/BASR and USING Statement
8. Analyzing Program Object Listing
9. (Identifying Location Counter, Op-Code, Operands, Data)
10. Putting an Address into a Memory Location
11. Load Address (LA instruction)
12. More Notes on Addressing
13. IBM System 370 Instruction Formats
14. Putting together concepts such as (Self-Defining Terms, Location Counter,
15. Literals, Absolute versus Re-locatable Expressions; USING, DROP, START, CSECT,
16. ENTRY; EQU, DC, DS, DSECT, ORG, LTORG, CNOP, END), Condition Code
17. Other Assembler directives such as TITLE, EJECT, SPACE, PRINT, END
18. Addressing Long Programs

QSAM File Handling

1. Macros used for QSAM file handling
2. DCB, MACRF, OPEN, CLOSE, PUT, GET

Character String Manipulation

1. Declaration Of Character Strings
2. Move Character (MVC instruction)
3. Logical Comparisons (CLC instruction)
4. Character Literals
5. Immediate Instruction (MVI and CLI instructions)

Arithmetic Instructions

1. LPR, LNR and LCR Instruction
2. Halfword Instructions (AH, SH, LH ….instructions)
3. Multiply Instruction (M, MR instruction)
4. Divide Instruction (D, DR instruction)

Compare and Branch Instructions

1. Condition Code And Branching
2. Arithmetic And Condition Code
3. Branch Instruction (BC And BCR)
4. More Complicated Masks
5. Extended Mnemonics And Arithmetic Instruction
6. Load And Test Register (LTR)
7. Compare Instruction (C instruction)
8. Compare And Compare Register (CR instruction)
9. Compare Halfword (CH instruction)
10. List of Extended Mnemonics After Compare Instruction

Testing and Debugging Errors In An Assembler Program

1. Reading / Analyzing Dump

Passing Parameter Data from JCL to Program

1. EX Instruction

Character Strings Revisited

1. Array Of Character Strings
2. Arrays Of Heterogeneous Data
3. Looping Through A Character String
4. MVCL, CLCL Instructions
5. TR, TRT Instructions (Validating Data, Translating Data Strings)

Packed Decimal Numbers

1. Declaration (Definition) of Packed Decimal Numbers
2. Packed Decimal Operations And Formats
3. Add Packed (AP instruction)
4. Subtract Packed (SP instruction)
5. Zero And Add Packed (ZAP instruction)
6. Multiplication Of Packed Decimal Numbers (MP instruction)
7. Divide Packed (DP instruction)
8. Compare Packed (CP instruction)
9. Arrays Of Packed Decimal Numbers
10. Converting Number Data From One Format to Another
11. (PACK, UNPK, CVB and CVD instructions)
12. ED and EDMK Instructions

Table Handling & Table Lookup Techniques

1. BCT and BCTR Instructions
2. Multi-level Tables/Arrays – Defining And Searching
3. Address Modification
4. Index Register Modification
5. Using An Index Register with An Explicit Base Register
6. Base Register Modification
7. BXLE and BXH Instruction

Characteristics Of A Good Assembler Language Program

Subprograms

1. Control Sections
2. Branching To And Returning From A Subprogram
3. Linkage conventions
4. Branch & Link (BAL), And Branch & Link Register (BALR)
5. Branch & Save (BAS), And Branch & Save Register (BASR)
6. Load Multiple And Store Multiple (LM and STM)
7. Passing Parameters
8. Saving Register Contents
9. Establishing Addressability
10. Returning A Value From A Function

Bit and Byte Manipulation

1. Shift Operations
2. Logical Shifts (SLL, SRL, SLDL, SRDL instructions)
3. Arithmetic Shifts (SLA, SRA, SLDA, SRDA instructions)
4. Logical Operations
5. The AND Operations (N instruction)
6. The OR Operations (O instruction)
7. The Exclusive OR Operations (X instruction)
8. Test Under Mask (TM instruction)
9. ICM, STCM, AND CLM Instructions
10. Walk Thru Of Machine Instruction Summary Of All Instructions

Macros

1. Simple macro
2. Symbolic parameters
3. System Variable Symbols
4. A look at code of IBM supplied macros such as SAVE, RETURN etc.

Reading / Analyzing Existing Program From Maintenance View Point

1. Assembler Documentation Hints -- DO'S and DON'TS