TAL Programmer's Guide

Declaring Simple Pointers in Structures
Using Structures
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Addresses Simple
Pointers Can Contain
The addressing mode and data type of a simple pointer determines the kind of address
the pointer can contain, as described in Table 8-4.
Table 8-4. Addresses in Simple Pointers
Addressing Mode Data Type Kind of Addresses
Standard STRING 16-bit byte address in the lower 32K-word area of the user data
segment.
Standard Any except
STRING
16-bit word address anywhere in the user data segment.
Extended STRING 32-bit byte address, normally in the automatic extended data
segment.
Extended Any except
STRING
32-bit even-byte address, normally in the automatic extended
data segment. (If you specify an odd-byte address, the results
are undefined.)
Allocating Simple
Pointers in Structures
The compiler allocates storage for simple pointers declared within structures when it
allocates the encompassing structure. It allocates one word for each standard pointer
and one doubleword for each extended pointer. The storage area depends on the
scope and addressing mode of the encompassing structure.
The compiler does not allocate space for the data to which the pointer points. You can
store addresses of previously declared items in pointers as described in “Assigning
Addresses to Pointers in Structures” later in this section. Otherwise, you must manage
the allocation of the data to which the pointer points, as described in Appendix B,
“Managing Addressing.”