- 2.2.12.3. -
Table of Contents
2. TMT Pascal Language Description
2.2. Pascal Language Structure
2.2.12. Procedures and Functions
2.2.12.3. External Declaration
2.2.12.3. External
Declaration
The External clause is used to define a procedure
that is linked in from an assembly object.
Example:
;----------------- [vga.asm] ----------------
IDEAL
P386
MODEL FLAT,PASCAL
CODESEG
GLOBAL SETVIDEOMODE: PROC
PROC SETVIDEOMODE USES EAX, MODE: WORD
MOV AX, [MODE]
INT 10H
RET
ENDP SETVIDEOMODE
GLOBAL CLEARVGA: PROC
PROC CLEARVGA USES ECX, COLOR: BYTE
MOV EDI, 0A0000H
MOV AL, [COLOR]
MOV AH, AL
MOV ECX, EAX
SHL EAX, 16
MOV AX, CX
MOV ECX, 64000/4
CLD
REP STOSD
RET
ENDP CLEARVGA
END
;--------------------------------------------
///////////////// [Test.pas] ////////////////
program Test;
{$ifndef __DOS__}
This program can not be compiled for OS/2 or Win32
{$endif}
uses
CRT;
{$l vga}; // include vga.obj file
procedure SetVideoMode(Mode: Word); external;
procedure ClearVGA(Color: Byte); external;
begin
SetVideoMode($13); // setup VGA/MCGA mode 320x200
ClearVGA(10); // fill screen with green color
ReadKey; // wait for key hit
ClearVGA(15); // fill screen with white color
ReadKey; // wait for key hit
ClearVGA(0); // fill screen with black color
ReadKey; // wait for key hit
SetVideoMode($03); // setup VGA text mode 80x25
end.
See also:
Dynamic-Link Libraries (DLL’s)
- 2.2.12.3. -
