Source file: /~heha/hs/vcall0.zip/VCALL0.C

#include "vcall0.h"
void far *VCall0_Entry;

/* Routine im Kernel-Mode rufen, sofern VCALL0.386 geladen, sonst direkt */
unsigned Call0(unsigned far (*routine)(void)){
 asm{	mov	ax,word ptr VCall0_Entry[0]
	or	ax,word ptr VCall0_Entry[2]
	jz	lbl1		/* NULL? */
	les	bx,[routine]
	mov	ah,1		/* Funktionsnummer */
	call	[VCall0_Entry]
	jmp	lbl2
 }lbl1: asm{
	call	[routine]
 }
lbl2:
 return _AX;
}

unsigned GetVCall0Ver(void){
 asm{	mov	ax,word ptr VCall0_Entry[0]
	or	ax,word ptr VCall0_Entry[2]
	jz	lbl1		/* NULL? */
	xor	ah,ah
	call	[VCall0_Entry]
 }
lbl1:
 return _AX;
}

char high_freq(long hz, void far (*routine)(void)) {
// liefert TRUE oder FALSE
 asm{	mov	cx,word ptr VCall0_Entry[2]
	stc
	jcxz	hf1		// NIL?
	db 0x66; mov dx,word ptr [hz]
	les	bx,[routine]
	mov	ah,2		// Funktionsnummer
	call	[VCall0_Entry]
 }hf1: asm{
	mov	al,0
	jc	hf2
	inc	al
 }hf2: return _AL;
}

void far *VXDLDR_Entry;
char VxDName[]="VCALL0.386";

/* Initialisierung: Pointer ermitteln und setzen */
unsigned Get_VCall0_Entry(void){
 asm{	mov	bx,VCall0_Device_ID
	xor	di,di
	mov	es,di				/* also mit Null laden */
	mov	ax,0x1684
	int	0x2f
	mov	ax,es
	mov	word ptr [VCall0_Entry],di
	mov	word ptr [VCall0_Entry+2],ax	/* Einsprungadresse zum VxD */
 }
 return _AX;
}

void VCall0_Init(void){
 if (!Get_VCall0_Entry()) {
 asm{	mov	bx,0x0027	// VXDLDR-Device-ID
	mov	ax,0x1684
	int	0x2F
	mov	ax,es
	or	ax,ax		// <>0?
	jz	e		// nein, wohl kein Windows95?
	mov	word ptr [VXDLDR_Entry],di
	mov	word ptr [VXDLDR_Entry+2],ax
	mov	dx,offset VxDName
	mov	ax,0x0001	// Load_VxD
	call	[VXDLDR_Entry]
	jc	e		// Fehler!
  }
 }
 Get_VCall0_Entry();	// Zweiter Versuch
e:
}

void VCall0_Exit(void) {
 asm{	mov	ax,0x0002	// Unload_VxD
	mov	bx,VCall0_Device_ID
	call	[VXDLDR_Entry]
 }
}