Declaring a Communal Variable of a Record Type

• Microsoft Macro Assembler for MS-DOS, versions 5.0, 5.1, 5.1a, 6.0, 6.0a, and 6.0b
• Microsoft Macro Assembler for OS/2, versions 5.1, 5.1a, 6.0, 6.0a, and 6.0b

SUMMARY

In order to declare a communal variable of a record type, declare the variable whose size matches the size of the record type. There is no need to specify that the variable is of the record type.

MORE INFORMATION

The following sample program demonstrates this information:

Sample Code

;Assemble options needed: none

; module 1

        .model small
        DOSSEG

EXTRN   proc2:proc
        .stack 100h

        .data
color   RECORD   blink:1, back:3, intense:1, fore:3
        COMM     near pixel:byte     ; use "byte" because
                                     ; color has size byte.
        .code

        MOV ds, ax

        MOV pixel, color <1,2,1,3> ; now the variable pixel
                                   ; should contain abh (1 010 1 011)
        CALL proc2
        MOV ax, 4c00h
        INT 21h

        END start

        .model small
        DOSSEG

        .stack 100h

        .data
color   RECORD   blink:1, back:3, intense:1, fore:3
        COMM     near pixel:byte

        .code

proc2   PROC
        MOV ah, 0
        MOV ah, pixel  ; ah should contain abh (1 010 1 011)
        RET
proc2   ENDP

        END