--- uae/src/serial.c	2018/04/24 16:38:39	1.1
+++ uae/src/serial.c	2018/04/24 16:38:56	1.1.1.2
@@ -3,7 +3,7 @@
   * 
   *  Serial Line Emulation
   *
-  * (c) 1996 Stefan Reinauer
+  * (c) 1996 Stefan Reinauer <stepan@matrix.kommune.schokola.de>
   */
 
 #include "sysconfig.h"
@@ -13,8 +13,13 @@
 #include "options.h"
 #include "memory.h"
 #include "custom.h"
+#include "readcpu.h"
 #include "newcpu.h"
 
+#ifndef O_NONBLOCK
+#define O_NONBLOCK O_NDELAY
+#endif
+
 void serial_init(void);
 void serial_exit(void);
 
@@ -86,7 +91,7 @@ UWORD SERDATR(void)
     char z;
 
     if (!use_serial)
-	return;
+	return 0;
 
     if ((read (sd, &z,1))==1) {
 	serdat=0x6100;