IBM Version 4 manual Interface Instructions-Introduction, Machine

Chapter

7. Machine

Interface

Programming

This

chapter

is

for

programmers

interested

in

creating

machine

interf

grams. While

some

MI instructions are discussed within the context of

develop MI programs, this chapter makes no attempt to review the ful

instructions. The

goal

of this chapter is to provide a

sufficient ba

so

that

you

can

begin

to

use

the

MI

language. After

reading

this

should

be

able

to develop, create, run, and debug an

AS/400

MI

prog

reading

this

chapter,

you

will

need SystemaccessAPItoRefthe,rence

SC41-5801, and theMachine Interface Functional ,ReferenceSC41-5810, because

these

two

books

are

referred

to extensively.

Machine

Interface Instructions—Introduction

Programs and procedures are the two

basic

units of

execution

on

the

grams come in two flavors: the

original

program

model

(OPM)

and

the

Int

Language

Environment

(ILE). MI programs can be created only for the OP

ronment. If

you

require

ILE support

in

the

development

of your

appli

ILE

C

and

its built-in

MI

support.

In the OPM environment, a program is comprised of two basic components object definition table (ODT) and an instruction stream. In the case grams, the program is created using the Create Program (QPRCRTPG) API. API is documented inSystemthe API Reference.

	1					the	MI
The ODT is the means for defining thatall objarectsreferred to by
instruction stream. An ODT definition		of an object does not actually a
storage	for the object. It does,	however,	define when		and	how	muc
be allocated and also the attributes of the storage				(for		example,
object). The ODT is built from the		declare	(DCL) statements found				in
used to create a program. Because		DCL statements are actually instru
QPRCRTPG	API and not MI instructions,	they are	defined	in	the	QPRCRTPG

The types of objects that can be declared are:

Scalar

Pointer

Machine space pointer

Operand list

Instruction definition list

Exception description

Space

Constant

The instruction stream defines the set of operations to be performe program. The instruction stream is built from the MI instructions found source used to create a program. The various MI instructions that y

defined in Machinethe Interface Functional .Reference

1	The	term objectsin this	chapter refers to program	data elements and not OS/400 object types such as a *F
	and	so on.
	Copyright IBM Corp.		1997	7-1