From 35cfe5d5c759e104803f4756a39e02f46a6829ad Mon Sep 17 00:00:00 2001
From: Sjoerd van der Berg <harekiet@users.sourceforge.net>
Date: Sat, 19 Oct 2002 17:27:28 +0000
Subject: [PATCH] Added a multiplex handler for 0x1680 for dos programs to give
 up their time slice

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@362
---
 src/dos/dos_misc.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/dos/dos_misc.cpp b/src/dos/dos_misc.cpp
index 9072d337..5280a529 100644
--- a/src/dos/dos_misc.cpp
+++ b/src/dos/dos_misc.cpp
@@ -54,6 +54,16 @@ static Bitu INT2A_Handler(void) {
 	return CBRET_NONE;
 };
 
+static bool DOS_MultiplexFunctions(void) {
+	switch (reg_ax) {
+	case 0x1680:	/*  RELEASE CURRENT VIRTUAL MACHINE TIME-SLICE */
+		//TODO Maybe do some idling but could screw up other systems :)
+		reg_al=0;	
+		return true;
+	}
+	return false;
+}
+
 
 void DOS_SetupMisc(void) {
 	/* Setup the dos multiplex interrupt */
@@ -61,6 +71,7 @@ void DOS_SetupMisc(void) {
 	call_int2f=CALLBACK_Allocate();
 	CALLBACK_Setup(call_int2f,&INT2F_Handler,CB_IRET);
 	RealSetVec(0x2f,CALLBACK_RealPointer(call_int2f));
+	DOS_AddMultiplexHandler(DOS_MultiplexFunctions);
 	/* Setup the dos network interrupt */
 	call_int2a=CALLBACK_Allocate();
 	CALLBACK_Setup(call_int2a,&INT2A_Handler,CB_IRET);