pTAL Conversion Guide

pTAL Conversion Guide—527302-002
2-1
2 Program Structure
TAL and pTAL support BLOCK declarations with which, in any one compilation, you
can declare:
•
One unnamed block
•
One PRIVATE block
•
Any number of named blocks
BELOW
varies:
AT
varies:
For more information about blocks, see:
•
TAL Reference Manual
•
TAL Programmer’s Guide
TAL pTAL
Generates optimal TNS object code Ignored
TAL pTAL
Establishes a common global
communication area: for example,
between programs and separately
maintained run-time libraries
The native compilers report a warning if
you use an AT(0) clause and report an
error if you use an AT clause with a
parameter other than zero.
Cannot allocate variables at physical
location zero. The logical base of a native
process’s data can vary from one run to
the next such that AT(0) might not refer to
the same memory location each time you
run a program.
BLOCK identifier
PRIVATE
AT
BELOW
(0)
(64)
(256)
;
data-declaration ;
END BLOCK
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