Address subtypes

    Symbol subtypes describe whether the symbol represents the address of
    a byte, a word, and so forth. The following tables show the simple and
    complex address subtypes that Turbo Assembler provides:


  Simple address subtypes

    Type expression     Meaning
    ───────────────────────────────────────────────────────────────────
    UNKNOWN             Unknown or undetermined address subtype
    BYTE                Address describes a byte
    WORD                Address describes a word
    DWORD               Address describes a 4-byte quantity
    PWORD or FWORD      Address describes a 6-byte quantity
    QWORD               Address describes an 8-byte quantity
    TBYTE               Address describes a 10-byte quantity
    SHORT               Address describes a short label/procedure address
    NEAR                Address describes a near label/procedure address
    FAR                 Address describes a far label/procedure address
    PROC                Address describes either a near or far label/
                        procedure address, depending on the currently
                        selected programming model (memory model)
    DATAPTR             Address describes either a word, dword, or pword
                        quantity, depending on the currently selected
                        programming model
    CODEPTR             Address describes either a word, dword, or pword
                        quantity, depending on the currently selected
                        programming model
    strucname/unionname Address describes an instance of the named structure
                        or union
    tablename           Address describes an instance of the named table
    recordname          Address describes an instance of the named record;
                        either a byte, word, or dword quantity
    enumname            Address describes an instance of the named enumerated
                        data type; either a byte, word, or dword quantity
    typename            Address describes an instance of the named type
                        (cf. TYPEDEF directive)
    TYPE expression     Address describes an item whose subtype is the
                        address subtype of the expression (Ideal mode only)
    proctypename        Address describes procedure of proctype (cf. PROCTYPE
                        directive)

  ───────────────────────────────────────────────────────────────────────────
  Complex address subtypes

    Several directives (e.g. ARG, LOCAL) let you declare and use complex
    address subtypes. These type expressions are similar to C in that they
    can represent multiple levels of pointer indirection, for example, the
    complex type expression

        PTR WORD

    represents a pointer to a word. (The size of the pointer depends on
    the segmentation model you selected with the MODEL directive.) The
    following table shows a syntax summary of complex address subtypes:

    Syntax                                    Meaning
    ───────────────────────────────────────────────────────────────────────
    simple_address_subtype                    The specified address subtype

    [distance] PTR [complex_address_subtype]  A pointer to the specified
                                              complex address subtype, the
                                              size of which is determined
                                              by the current MODEL or by
                                              the specified distance, if
                                              present


    You can describe the optional distance parameter in the following ways:

    Syntax              Meaning
    ───────────────────────────────────────────────────────────────────────
    NEAR                Use a near pointer; can be either 16 or 32 bits,
                        depending on the current MODEL
    FAR                 Use a far pointer; can be either 32 or 48 bits,
                        depending on the current MODEL
    SMALL NEAR          Use a 16-bit pointer; ≥80386 only
    LARGE NEAR          Use a 32-bit near pointer; ≥80386 only
    SMALL FAR           Use a 32-bit far pointer; ≥80386 only
    LARGE FAR           Use a 48-bit far pointer; ≥80386 only

    The type of the object being pointed to is not strictly required in
    complex pointer types; Turbo Assembler only needs to know the size of
    the type. Therefore, forward references are permitted in complex pointer
    types (but not in simple types).