HP Vectra Technical Reference Manual page 404

APPENDIX E
E. SYSTEM EQUATE FILE
This appendix contains the Macro Assembler (MASM) listing of the system equate file,
EQUATES.ASM.
Equates are assembly language (MASM) directives. The term equate as used here includes the
MASM directives: EQU,
'= "
STHUC, RECORD, and MACRO. They allow the programmer to
assign ASCII strings (names) to numeric constants, data structures, data records and macros. The
name can then be used in programs to define data structures, code structures, or record
structures. When the program is assembled, MASM substitutes the value associated with the
name for every occurance of the name in the source code.
~
The MASM directive 'INCLUDE' is used
by
programs to define constants, data structures or code
structures commonly used by different programs. When a particular equate or group of equates
is needed in a program, the programmer does not have to either define a new equate name for
the variable or type it into the program. The programmer can use the 'INCLUDE' statement to
define the equate. At assembly time the INCLUDE directive causes the assembler to read a
specified file and process it as if its contents were actually in the orignal source code file. See the
HP
Vectra MS-DOS Macro Assembler manual for more information on include files.
E.1 The Equate File
The equate file supports prograrnmer's access to both the STD-BIOS and EX-BIOS. Support is
provided for software interrupt numbers, interrupt function and subfunction codes, and data
structures associated with the various fUrlctions. Commonly used MACROS are also defined.
System Equate File 395