Assembler courses.

We sometimes give classroom training. Ususally, however, we would train your people on the job, in your own office. This enables us to attune the contents of the course on the one hand to your knowledgeability on assembler, and on the other hand to your specific environment. Moreover, anything learned can immediately be checked and/or applied in your own real-life situation.

Topics to be treated have been classified into six categories, listed below. For each course you can make a selection from these standard lists of topics. Other topics that may be of special interest to you may be added.

Introduction and general principles
Assembler starter
Assembler for application programmers
Assembler for experienced programmers
Assembler - Macro Facility
Bixoft eXtended Assembler language

Whichever selection you make, we think at least the following topics need to be treated:

Architecture of the computer and the operating system.
Organization of virtual storage, address- and data-spaces, addressing modes and residency modes, calling mechanisms and the linkage stack.
Instructions.
All unprivileged instructions from IBM's 'Principles of Operation'. That is to say:
- General Instructions.
- Decimal Instructions.
- Floating-Point Instructions.
- Relevant Control Instructions.
The most relevant standard-macros from:
- Assembler Services Reference.
- Macro Instructions for Data Sets.
Coding techniques and structured programming.
Modularization, segmentation, CSECTS and DSECTS, subroutines, memory management, in-line and out-of-line error handling, exceptions, abends.
Reusability, reenterability, refreshability.
The differences between these kinds of programs, and their application. The consequences for the way one codes such programs.
Assembler directives.
Usage of CNOP for alignment, DROP and USING for addressability. LTORG, DC and DS for organizing storage areas, variables and constants. EQU for naming constants and addresses.
Use of macros and conditional assembly.
Conditional assembly in open code, optimising, debugging with SNAP-dumps. The application of macros in conjunction with access methods.
Design of macros.
Use of macros versus copy members. What lends itself for macrofication. Interface considerations. Documentation of macros. Directing expansion with parameters. Lists of parameters. Location of macro: in the source or in a macro library?

Introduction and general principles.

The topics for this course have been subdivided into four chapters:

Basic computing knowledge
Architectur of machine and operating system
Most important control blocks
Literature

Basic computing knowledge
- Components: processor, storage, peripherals
- Instruction processing
- Sequentially
- Conditionally
- Interrupts
  - Receipt
  - Return
  - Status information
- Boolean logic
  - Truth tables
  - AND, OR, XOR, NOT
  - Implication, equivalence
- Multi-tasking
  - Synchronisation
  - Serialisation
  - Semaphores
  - Lock-out
  - Deadlock
  - Dispatching
- Multi-processing
  - Tightly coupled (LPAR/MONOPLEX)
  - Loosely coupled (SYSPLEX)
Architecture of machine and operating system
- Mainframe
  - Processors
  - Main storage, expanded storage
  - Devices
  - Channels
  - Coupling Facility
  - Sysplex
- Historical overview
  - 360 and 370 - 24-bits
  - 370/XA - 31-bits
  - 390/ESA - ALETs
- Virtual storage concepts
  - Dynamic Address Translation
  - Pages, frames, slots
  - Segment tables, page tables
  - Address-spaces, data-spaces, hiper-spaces
    - Batch jobs, TSO-sessions, Started tasks
    - Paging
      - Page steal
      - Least Recently Used
      - Reference bit, change bit
    - Organisation
      - PSA, SYS, PVT, LSQA
      - SYS: CSA, LPA, SQA, Nucleus
      - ESYS: Extended Nucleus, ESQA, ELPA, ECSA
      - EPVT, ELSQA
  - V=R versus V=V
  - DAT-on versus DAT-off, TLB
  - Primary mode versus other modes, ALB
- Storage and addressing:
  - Absolute
  - Real and expanded
  - Virtual
    - Primary
    - Secondary
    - AR-specified
    - Home
  - Logical
  - Effective
  - Wrap-around
- Storge protection
  - Key-controlled protection
  - Fetch protection
  - Page protection
  - Low-address protection
- Registers:
  - Program Status Word
    - DAT mode
    - PSW key
    - Problem state versus Supervisor state
    - Address space control
    - Condition code
    - Program mask
    - Addressing mode
    - PER mode
  - Prefix register
    - Interrupts and interrupt classes
  - Control registers
  - Access registers
  - General purpose registers
    - Pairs of GPRs
  - Floating point registers
    - Pairs of FPRs
  - Floating point status register
  - Vector registers
  - Vector status register
- Addressing mode, residency mode, cross memory mode
  - Amode 24 versus 31, Amode any
  - Rmode 24, any
  - Cross memory mode
  - Addressing modes:
    - Primary mode
    - Secondary mode
    - Access Register mode
    - Home space mode
  - Using registers in instructions
    - With a base register only
    - With both a base and an index register
    - Using R0
    - Simple USING and DROP statements
- Units of work
  - Address spaces, tasks, and subtasks
  - Task mode versus SRB mode
  - Asynchronous exits
  - Swap-in, swap-out
  - Dispatching
- Overview of modes:
  - JOB/TSU/STC
  - Task/SRB
  - Non-reusable/reusable/reenterable/refreshable
  - Rmode 24/ANY
  - Amode 24/31/ANY
  - ASC mode primary/secondary/home/AR
  - SVC/Problem
  - Process-must-complete mode
Most important control blocks
- PSA
- CVT, SCVT, ASVT
- ASCB, ASSB, ASXB
- SRB
- TCB, STCB, JSCB, TIOT, JFCB
- RB (PRB, SVRB, IRB), CDE
- UCB
- Save area chain, Linkage stack
Literature
- z/Architecture Principles of Operation
- z/OS V1R1.0 MVS Extended Addressability Guide

Assembler starter.

The topics for this course have been subdivided into seven chapters:

Assembler
Architecture of machine and operating system
Instruction set
Most relevant standard macros
Coding techniques and structured programming
Assembler directives
Literature

Assembler
- Module formats
  - Source member
    - Label field
    - Opcode field
    - Operands field
      - Symbolics
      - Literals
    - Comment field
    - Continuation
  - Listing
    - Option summary
    - External symbol dictonary
    - Assembly
      - Title and using overview
      - Location and object code
      - Source code
      - Macro level and name
    - Relocation dictionary
    - Cross reference
    - Unreferenced symbols
    - Macro source summary
    - Macro cross reference
    - DSECT cross reference
    - Using map
    - Register cross reference
    - Summary
  - Object member
  - Load member
- Types of opcode
  - Executable instructions
  - Data instructions
    - DS versus DC
    - LTORG
    - CSECTs versus DSECTs
  - Assembler directives
  - Conditional assembly
- Linkage editor
- Loader
Architecture of machine and operating system
- Registers
  - GPRs and pairs of GPRs
  - Addressing and R0
- Calling conventions
  - Save areas and save area chaining
  - Usage of R13 as save-area pointer
  - Usage of R14 for return adress
  - Usage of R15 for entry-point / returncode (n*4)
  - Usage of R1 as parm-pointer / parmlist pointer / Reason code / result value
    - Lay-out of JCL-parm
    - Lay-out of parmlist, end-of-plist marker
  - Usage of R0 as extra parm / result value
- Calling mechanisms
  - SVC + LPSW --> FLIH+SLIH
  - BAL/BALR + BR --> obsolete
  - BAS/BASR + BSM/BR --> Fast
  - BASSM + BSM --> Glueing
  - PC/BAKR + PR --> Stack
Instruction set
- Data formats
  - Zoned data format, Sign, ASCII/EBCDIC
  - Binary data format
    - Signed / unsigned
    - Halfword / fullword / doubleword
  - Address format: 24-bit, 31-bit, Amode bit, ALETs
  - String formats
  - Alignment
- Unprivileged instructions
  - Arithmetic operations
    - Add: A, AR, AH, AHI, AL, ALR
    - Subtract: S, SR, SH, SL, SLR
    - Multiply: M, MR, MH, MHI, MS, MSR
    - Divide: D, DR
  - Logical operations
    - Compare: C, CR, CH, CHI, CL, CLR, CLI, CLC, CLM, CLCL, CLCLE, TM, TMH, TML, CLST, CUSE
    - And: N, NR, NI, NC
    - Or: O, OR, OI, OC
    - Exclusive or: X, XR, XI, XC
  - Moving data
    - Register to register: LR, LTR, LCR, LNR, LPR
    - Storage to register: L, LH, LHI, LM, IC, ICM
    - Register to storage: ST, STH, STM, STC, STCM
    - Storage to storage: MVC, MVI, MVCIN, MVCL, MVCLE
    - Other: LA
  - Program flow control
    - Branching: BC, BCR, BAL, BALR, BAS, BASR, BASSM, BSM, SVC + BRAS, BRC
    - Extended mnemonics: B, BE, BNE, BL, BNL, BH, BNH, BM, BNM, BZ, BNZ, BO, BNO, BP, BNP, BR, BER, BNER, BLR, BNLR, BHR, BNHR, BMR, BNMR, BZR, BNZR, BOR, BNOR, BPR, BNPR
Most relevant standard macros
- Program control
  - Standard linkage: SAVE and RETURN
  - Abort program: ABEND
  - Invoke sub-program statically: CALL
  - Invoke sub-program dynamically: IDENTIFY and LINK/LINKX or LOAD and DELETE with BR/BASR/BASSM
  - Program transfer: XCTL/XCTLX
- Time
  - Determine current time: TIME or CONVTOD, STCKCONV
  - Used CPU-time in task-mode: TIMEUSED
- Other services
  - Directing code generation: SPLEVEL, SYSSTATE
- Macro Instructions for QSAM move mode
  - OPEN, CLOSE
  - GET, PUT
  - DCB, EODAD
  - Record formats
    - Fixed / Fixed Blocked
    - Variable / Variable Blocked
Coding techniques and structured programming
- Modularisation, segmention, CSECTs, subroutines, and location counters
- Comments regarding design
- Comments
  - Blocks
  - On source lines
- Lay-out
- Awful coding techniques
  - Missing or erroneous comments
  - Useless comments
  - Self-modifying code:
    - Changing condition of a branch instruction
    - Changing target of a branch instruction, S-con
    - Changing opcode
  - Misuse of location counter:
    - *-offset
    - Same for label + or - offset
  - 'Magical' numbers
  - Too many base registers
  - Unlogical EQUates
Assembler directives
- Assembly control
  - *PROCESS
  - START
  - END
  - ICTL
  - ISEQ
  - COPY
  - OPSYN
  - EXITCTL
- Object control
  - AMODE
  - RMODE
  - CATTR
  - ALIAS
  - ENTRY
  - EXTRN
  - PUNCH
  - REPRO
  - WXTRN
- Listing control
  - TITLE
  - SPACE
  - EJECT
  - CEJECT
  - ASPACE
  - AEJECT
  - PRINT
  - PUSH PRINT
  - POP PRINT
- Generating data
  - DC
    - Duplication, alignment
    - Type, Attribute
    - Modifier
    - Value
  - DS
  - EQU, EQU *, EQU *+..., EQU *-...
  - LTORG
  - CNOP
- Controlling addressability
  - CSECT
  - RSECT
  - DSECT
  - USING
    - Ordinary
    - Labeled
    - Dependent
    - Labeled dependent
  - DROP
    - Register
    - Label
  - PUSH USING
  - POP USING
  - ORG
Literature
- High Level Assembler Programmer's Guide
- High Level Assembler Language Reference
- z/OS V1R1.0 MVS Assembler Services Guide
- z/OS V1R1.0 MVS Assembler Services Reference (2 delen)
- z/OS V1R1.0 DFSMS Using Data Sets
- z/OS V1R1.0 DFSMS Macro Instructions for Data Sets
- z/OS V1R1.0 DFSMS Program Management
- z/OS V1R1.0 MVS System Codes
- z/OS V1R1.0 MVS System Messages (10 delen)

Assembler for application programmers.

The topics for this course have been subdivided into eight chapters:

Assembler
Architecture of machine and operating system
Instruction set
Most relevant standard macros
Coding techniques and structured programming
Reusability
Assembler directives
Literature

Assembler
- Module formats
  - Load module attributes: RF, RN, RU, NX, SC
- Assembler function
  - Assembly parameters
    - SYSPARM
  - Run-time logic
    - SYSABEND, SYSUDUMP, SYSMDUMP
    - Tracing
    - SNAP-dumps
    - IPCS
    - Other debugging tools: IDF, XDC, ???
Architecture of machine and operating system
- Calling conventions
  - Linkage stack, F1SA-pointer
  - Usage of R15 for returncode (n*4)
    - Jump tables
  - Usage of R1 as parmlist pointer
    - Lay-out of parmlist, end-of-plist marker in access register mode
- Calling mechanisms and the linkage stack:
  - SVC/MC + LPSW --> FLIH+SLIH
  - PC + PT/LPSW
  - BAKR + PR --> Overhead
  - Glue modules
    - Static call using a Vcon
    - Dynamic call using LOAD and DELETE macros
Instruction set
- Data formats
  - Packed decimal format, Sign
  - Floating point format
    - Short format (32-bit E/D)
    - Long long format (64-bit D/W)
    - Extended format (128-bit X)
- Unprivileged instructies
  - Arithmetic operations
    - Conversion: CVB, CVD, PACK, UNPK
  - Logical operations
    - Shifting: SLA, SLL, SLDA, SLDL, SRA, SRL, SRDA, SRDL
  - Moving data
    - Register to register: CPYA, EAR, SAR
    - Storage to register: LAM
    - Register to storage: STAM
    - Storage to storage: MVPG (1), MVN, MVZ, MVO, TR, TRT, MVST
    - Other: LAE, SRST
  - Program flow control
    - Branching: MC
    - Loop control: BCT, BCTR, BRCT, BXH, BRXH, BXLE, BRXLE
    - Other: EX
      - all instructions except EX
      - length field in: MVC, CLC, TR, TRT
      - mask field in: TM, BC, BCR
  - Other general instructions
    - Checksum: CKSM
    - Sorting: CFC, UPT
    - Serialisation: TS, CS, CDS, PLO
    - Timing: STCK
    - Program mask: IPM, SPM
- Decimal Instructions
  - Arithmetic operations
    - Add: AP, ZAP
    - Subtract: SP
    - Multiply: MP, SRP
    - Divide: DP, SRP, rounding
  - Logical operations
    - Compare: CP
  - Moving data
    - Storage to storage: ED, EDMK
- Floating-Point Instructions
  - Arithmetic operations
    - Add: AE, AER, AD, ADR, AXR, AU, AUR, AW, AWR
    - Subtract: SE, SER, SD, SDR, SXR, SU, SUR, SW, SWR
    - Multiply: ME, MER, MD, MDR, MXD, MXDR, MXR
    - Divide: DE, DER, DD, DDR, DXR, HER, HDR
    - Square root: SQDR, SQER
  - Logical operations
    - Compare: CE, CER, CD, CDR
  - Moving data
    - Register to register: LER, LDR, LTER, LTDR, LCER, LCDR, LNER, LNDR, LPER, LPDR, LRER, LRDR
    - Storage to register: LE, LD
    - Register to storage: STE, STD
- Control instructions
  - Program flow control
    - Branching: BAKR, PC, PR, PT
  - Moving data
    - Storage to register: EREG, ESTA
    - Register to storage: MSTA
  - Controlling the PSW
    - Addressing mode: IAC, SAC, SACF
  - Other control instructions
    - Storage: IVSK
    - Testing addresses: TAR
Most relevant standard macros
- Program control - advanced:
  - Program interruption exits: SPIE and ESPIE
- Controlling storage
  - Storage: FREEMAIN en GETMAIN
  - Storage: STORAGE
  - Structures: CPOOL and subpools
- Communication:
  - Inserting messages in the system log: WTL
- Other services
  - Debugging: SNAP/SNAPX, IEATDUMP
  - Data-in-Virtual: DIV
- Macro Instructions for Data Sets
  - OPEN, CLOSE
  - READ, WRITE, GET, PUT, ERASE
  - CHECK
  - DCB, DCBD, DCBE
    - Exits, EODAD, SYNAD
  - ACB, RPL
  - Record formats
    - Fixed / Fixed Blocked
    - Variable / Variable Blocked
    - Spanned
    - Undefined
  - Access methods: BSAM, QSAM-locate, QSAM-move, QSAM-data, BPAM, BISAM, QISAM, BDAM, EXCP/EXCPVR, VSAM-ESDS, VSAM-KSDS, VSAM-RRDS, VSAM-LDS, IMS, DB2
  - CHKPOINT
  - NOTE, POINT
  - XLATE
Coding techniques and structured programming
- Controlling storage, paging
- In-line and out-of-line error handling
- Loops with BCT/BCTR
- Loops with BXLE/BXH
- Locality of reference and caching
- Exceptions and SPIE/ESPIE
- Abends and STAE/ESTAE
Reusability
- Non-reusable programs
- Serially reusable programs
- Reenterable programs
- Refreshable programs
  - Performance considerations
- Consequences for programming techniques
  - Macro-variants: MF=S, MF=L, MF=(E,addr), MF=(G,addr)
  - Generating executable code "on the flight"
Assembler directives
- Output control
  - ADATA
- Generating data
  - CCW, CCW0, CCW1
- Controlling addressability
  - LOCTR
  - COM
  - CXD
  - DXD
Literature
- z/OS V1R1.0 DFSMSdfp Advanced Services
- z/OS V1R1.0 DFSMSdfp Checkpoint/Restart
- z/OS V1R1.0 DFSMSdfp Storage Administration Reference
- MVS Programming: Batch Local Shared Resources
- Debug Tool User's Guide and Reference
- HLASM V1R4 Toolkit Feature Interactive Debug Facility User's Guide
- HLASM V1R3 Toolkit Feature Interactive Debug Facility Reference Summary
- Don Nielsen (DonN@cmscms.com): 'Redesigning Assembler Language Development'

Assembler for experienced programmers.

The topics for this course have been subdivided into seven chapters:

Authorisation
Instruction set
Most relevant standard macros
Coding techniques and structured programming
Parallellisation
Introduction dump reading
Literature

Authorisation
- APF-authorisation
  - Link
  - Library
  - Only at job-step level
- Supervisor state
  - Through SVC
  - Through PC
- PSW key
Instruction set
- Unprivileged instructions
  - Moving data
    - Storage to storage: MVPG (1)
- Control instructions
  - Program flow control
    - Branching: BSA, BSG
  - Moving data
    - Register to register: EPAR, ESAR, SSAR
    - Storage to register: LASP, LCTL, LURA
    - Register to storage: STCTL, STURA
    - Storage to storage: MVCP, MVCS, MVCK, MVCDK, MVCSK, MVPG (2)
    - Other: LRA
  - Controlling the PSW
    - PSW-key: IPK, SPKA
    - System mask: STNSM, STOSM
    - Other: LPSW, SSM
  - Other control instructions
    - Storage: ISKE, IPTE, RRBE, SSKE
    - DAT: PALB, PTLB
    - Clock: SCK, SCKC, SPT, STCKC, STPT
    - Prefix: SPX, STPX
    - Testing addresses: TB, TPROT
    - Tracing: TRACE
    - Other: Diagnose, SIGP, STAP, STIDP
- I/O instructions
- Vector instructions
- Custom instructions
Most relevant standard macros
- Program control
  - Invoking a sub-program dynamically: SYNCH/SYNCHX
- Program control - advanced:
  - Subtask management: ATTACH/ATTACHX, DETACH, STATUS, CHAP
  - Catching abends: STAE, ESTAE/ESTAEX, SETRP
  - Linkage stack management: IEALSQRY, LSEXPAND
- Storage control
  - Subpool types
  - Cross memory: DSPSERV dataspace with ALESERV and TESTART
  - Cross memory: DSPSERV hiperspace with HSPSERV
  - Paging: PGSER or PGLOAD, PGOUT, and PGRLSE
- Serialisation
  - Resources: ENQ, DEQ, GQSCAN
  - Synchronisation: WAIT/POST and EVENTS
  - Named tokens: IEANTCR, IEANTRT, IEANTDL
- Communication:
  - Console info: CONVCON
  - Message to console: WTO, WTOR, DOM
- Time
  - Timer interrupts: STIMER, STIMERM, CPUTIMER, TTIMER
- Other services
  - Resource Management: RESMGR
  - Load module info: CSVAPF, CSVINFO, CSVQUERY, CSVRTLS
  - Unique identification of a task: TCBTOKEN
  - Parmlib members: IEFPRMLB
- Macro Instructions for Data Sets
  - DYNALLOC
    - Datasets
    - Output descriptors
Coding techniques and structured programming
- Abends, STAI, STAE, ESTAE/ESTAEX, FESTAE, FRR, Percolation
- Resource management
Parallellisation
- Lock-out, dead-lock
- Proving correctness
- Serialisation
  - ENQ/DEQ
  - Latches
  - CS/CDS/PLO
  - Local lock, CML lock, CPU lock
  - Hierarchy
- Synchronisation
  - ECB
  - Post/Wait/Events
Introduction dump reading
- Symptom dump
  - PSW and ILC
  - Load module identification
  - PSW data
  - GPRs and ARs
  - Locating error instruction
    - Determine loadmod offset
    - Find correct CSECT and offset
    - Locate error instruction
- SYSUDUMP / SYSABEND
  - TCB c.a.
  - Virtual storage map
  - ENQ/DEQ CBs
  - Data Management CBs
  - IOS CBs
  - RTM CBs
  - Stacks and Save Areas
  - Subsystem Area
  - LSQA
  - Subpools 229 and 230
  - Registers
  - Summary storage
  - Modules
  - User Subpools
  - Trace Table
    - Trace entry formats
Literature
- OS/390 V2R6.0 MVS Programming: Resource Recovery
- z/OS V1R1.0 MVS Authorized Assembler Services Guide
- z/OS V1R1.0 MVS Authorized Assembler Services Reference (4 volumes)
- z/OS V1R1.0 DFSMS Access Method Services for Catalogs
- z/OS V1R1.0 JES2 Macros
- z/OS V1R1.0 RACF Macros and Interfaces
- z/OS V1R1.0 RACROUTE Macro Reference
- z/OS V1R1.0 MVS Using the Functional Subsystem Interface
- z/OS V1R1.0 MVS Using the Subsystem Interface
- z/OS V1R1.0 MVS IPCS User's Guide
- z/OS V1R1.0 MVS IPCS Commands
- z/OS V1R1.0 MVS Dump Output Messages
- z/OS V1R1.0 JES2 Messages
- z/OS V1R1.0 RACF Messages and Codes
- z/OS V1R1.0 MVS Data Areas (5 volumes)
- z/OS V1R1.0 JES2 Data Areas (3 volumes)
- z/OS V1R1.0 RACF Data Areas

Assembler - Macro facility.

The topics for this course have been subdivided into six chapters:

Assembler
Assembler directives
Using macros and conditional assembly
Designing macros
OO-techniques in assembler
Literature

Assembler
- Assembler function
  - Pre-assembly logic
    - MNOTE, MHELP
    - MCALL/NOMCALL
  - Assembly logic
    - Two passes
Assembler directives
- Macro definitions
  - MACRO
    - Prototype statement
    - Positional parameters
    - Keyword parameters
  - MEND
  - Comments
  - MNOTE, severity levels
  - AREAD
  - AINSERT
- Pre-assembly variables
  - LCLA, GBLA
  - LCLB, GBLB
  - LCLC, GBLC
  - SETA
    - Built-in functions: AND, OR, XOR, NOT, SLA, SLL, SRA, SRL
    - SETAF
  - SETB
    - Built-in functions: NOT, AND, AND NOT, OR, OR, NOT
    - Logical terms: EQ, NE, GT, GE, LT, LE
  - SETC
    - Built-in functions: DOUBLE, FIND, INDEX, LOWER, UPPER
    - SETCF
    - Substring notation
  - Extended SET
  - Arrays
  - Created set symbols
- Pre-assembly control
  - Labels, ANOP
  - AIF
  - AGO
  - ACTR
  - MHELP
- System variables
  - &SYSDATE, &SYSDATC, &SYSTIME
  - &SYSECT, &SYSSTYP
  - &SYSLIST
  - &SYSNDX, &SYSNEST
  - &SYSPARM
Using macros and conditional assembly
- Using macros versus COPY
- DSECT-macros
- CSECT-macros
- Conditional assembly in open code
- Optimisation
- Replacing standard macros
- replacing opcodes by macros
Designing macros
- What lends itself for macrofication
- Documentation of macros
  - Pre-assembly logic
  - Assembly logic
  - Run-time logic
- Interface considerations
  - Assembly interface
  - Run-time interface
- Directing expansion using parameters
  - Lists of parameters
- Location of macro: in the source or in a library?
- Replacing opcodes
- replacing standard macros
OO-techniques in assembler
- Encapsulation
- Designing a class
- Designing methods
- Implementation in macros
Literature
- High Level Assembler Programmer's Guide
- High Level Assembler Language Reference
- John Ehrman (ehrman@vnet.ibm.com): 'Macros and Conditional Assembly Techniques, SHARE 94, Winter Conference 2000'

Bixoft eXtended Assembler language.

The topics for this course have been subdivided into four chapters:

Extended mnemonics
Assembler Directives
Macros for structured programming
Mapping macros

Extended mnemonics
- Conditional subroutine invocation
  - BALC, BALE, BALH, BALL, BALM, BALO, BALP, BALZ
    BALNE, BALNH, BALNL, BALNM, BALNO, BALNP, BALNZ
  - BASC, BASE, BASH, BASL, BASM, BASO, BASP, BASZ
    BASNE, BASNH, BASNL, BASNM, BASNO, BASNP, BASNZ
- Manipulating data
  - CLEAR
  - CPY
  - DEC, INC
  - LC, LT, LTA24, LTC, LTH, LTHU, STA24
  - MVPL
  - SET, SETOF, SETON
- Execute instructions
  - EXQ, EXCLC, EXMVC, EXTR, EXTRT, EXXC
- Extended type checking
  - GEN
  - IPK, LA, LR, TRT
- Other
  - EPSW
Assembler Directives
- Checking variables
  - CHKLIT, CHKMAP, CHKNUM, CHKREG
  - DISSECT, SPLIT
- Defining data
  - CMDTXT, TRTAB
  - DCL, DC, DCOVR, DS, DSOVR, NESTCB
  - EQU, EQUOVR, EQUREG
  - EXTRN, EXTRNOVR
  - LABEL
  - LTORG, RDATA, RLTORG
- Addressing
  - DROP
  - POP, PUSH
  - USE, USEDREGS, USING
- Other
  - EJECT, EJECTOVR, SPACE
  - END
  - GENMAPS
  - OPSYSNS
  - SYSPARM
Macros for structured programming
- Programs and subroutines
  - PGM, RETRN
  - ABND, ABNDPGM
  - BEGSR, ENDSR, EXSR
- Conditional expressions
  - IF, ELSE, ENDIF
  - CASE, ELSE, ENDCASE
  - DO, LOOP, LEAVE, ENDDO
  - GOTO
  - IF$, IF$ALC, IF$Ls, IF$LU
- Various
  - DBG, SNAPHDR, SNAPNTRY
  - GLUE
  - NTCR, NTRT, NTDL
  - RWTO
  - SETMODE
Mapping macros
- Assigned field types - a, b, c, f, g, j, p, v, 0
- Using MAP-macros in combination with GENMAPS
- Using MAP-macros in combination with DCL
- Using declared bits
- Using declared values
- Using defined registers
- Using conditional expressions
- Relation with DC, DS, EXTRN macros
- Function of DCOVR, DSOVR, EXTRNOVR macros
- MAPEQU, MAPBITS, MAPREGS
- MAPSAVE
- MAP control blocks

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