diff --git a/CMakeLists.txt b/CMakeLists.txt
index fb766ce..821b305 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -43,7 +43,7 @@ OPTION(MAIKO_DISPLAY_X11 "Use X11 for display." ON)
 IF(MAIKO_DISPLAY_X11)
   FIND_PACKAGE(X11 REQUIRED)
   SET(MAIKO_DISPLAY_X11_DEFINITIONS
-    "-DXWINDOW -DLOCK_X_UPDATES"
+    "-DXWINDOW"
   )
   SET(MAIKO_DISPLAY_X11_LIBRARIES X11::X11)
   SET(MAIKO_DISPLAY_X11_SRCS
diff --git a/bin/makefile-cygwin.x86_64-x b/bin/makefile-cygwin.x86_64-x
index 8129feb..f280cba 100644
--- a/bin/makefile-cygwin.x86_64-x
+++ b/bin/makefile-cygwin.x86_64-x
@@ -14,7 +14,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g3
diff --git a/bin/makefile-darwin.386-x b/bin/makefile-darwin.386-x
index 5125737..abd20e8 100644
--- a/bin/makefile-darwin.386-x
+++ b/bin/makefile-darwin.386-x
@@ -13,13 +13,13 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/opt/X11/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/opt/X11/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g
 DEBUGFLAGS = # -DDEBUG -DOPTRACE
 DFLAGS = $(DEBUGFLAGS) $(XFLAGS) \
-	-DRELEASE=351 -DSTACKCHECK -DFSBCHECK -DPCTRACE
+	-DRELEASE=351 # -DSTACKCHECK -DFSBCHECK -DPCTRACE
 
 LDFLAGS = -L/opt/X11/lib -lX11 -lm
 LDELDFLAGS =  -L/opt/X11/lib -lX11 -lm
diff --git a/bin/makefile-darwin.aarch64-x b/bin/makefile-darwin.aarch64-x
index f8f59e7..a92219f 100644
--- a/bin/makefile-darwin.aarch64-x
+++ b/bin/makefile-darwin.aarch64-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/opt/X11/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/opt/X11/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2
diff --git a/bin/makefile-darwin.ppc-x b/bin/makefile-darwin.ppc-x
index 8d35749..50db58f 100644
--- a/bin/makefile-darwin.ppc-x
+++ b/bin/makefile-darwin.ppc-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/usr/X11/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/usr/X11/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g
diff --git a/bin/makefile-darwin.x86_64-x b/bin/makefile-darwin.x86_64-x
index 0ac392b..e17f10b 100644
--- a/bin/makefile-darwin.x86_64-x
+++ b/bin/makefile-darwin.x86_64-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/opt/X11/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/opt/X11/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O1 -g
diff --git a/bin/makefile-freebsd.386-x b/bin/makefile-freebsd.386-x
index 69c113b..fa98c63 100644
--- a/bin/makefile-freebsd.386-x
+++ b/bin/makefile-freebsd.386-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/usr/local/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/usr/local/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS = -O2 -g
diff --git a/bin/makefile-freebsd.aarch64-x b/bin/makefile-freebsd.aarch64-x
index 6e263f8..7318c9a 100644
--- a/bin/makefile-freebsd.aarch64-x
+++ b/bin/makefile-freebsd.aarch64-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/usr/local/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/usr/local/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS = -O2 -g
diff --git a/bin/makefile-freebsd.x86_64-x b/bin/makefile-freebsd.x86_64-x
index 208bc2e..223ba40 100644
--- a/bin/makefile-freebsd.x86_64-x
+++ b/bin/makefile-freebsd.x86_64-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/usr/local/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/usr/local/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS = -O2 -g
diff --git a/bin/makefile-init-darwin.386 b/bin/makefile-init-darwin.386
index fbd168d..c7aaa62 100644
--- a/bin/makefile-init-darwin.386
+++ b/bin/makefile-init-darwin.386
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/opt/X11/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/opt/X11/include -DXWINDOW
 
 # OPTFLAGS is normally -O2, for INIT we want unoptimized in case we need to debug it
 OPTFLAGS =  -O0 -g
diff --git a/bin/makefile-init-darwin.aarch64 b/bin/makefile-init-darwin.aarch64
index c81744d..1314d4f 100644
--- a/bin/makefile-init-darwin.aarch64
+++ b/bin/makefile-init-darwin.aarch64
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
         $(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/opt/X11/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/opt/X11/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O0 -g3
diff --git a/bin/makefile-init-darwin.x86_64 b/bin/makefile-init-darwin.x86_64
index 943e903..322b4a8 100644
--- a/bin/makefile-init-darwin.x86_64
+++ b/bin/makefile-init-darwin.x86_64
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/opt/X11/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/opt/X11/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O0 -g
diff --git a/bin/makefile-init-freebsd.386 b/bin/makefile-init-freebsd.386
index 43ef0f6..ffb691b 100644
--- a/bin/makefile-init-freebsd.386
+++ b/bin/makefile-init-freebsd.386
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/usr/local/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/usr/local/include -DXWINDOW
 
 # OPTFLAGS is normally -O0 for init
 OPTFLAGS = -O0 -g
diff --git a/bin/makefile-init-freebsd.aarch64 b/bin/makefile-init-freebsd.aarch64
index e39644c..be70868 100644
--- a/bin/makefile-init-freebsd.aarch64
+++ b/bin/makefile-init-freebsd.aarch64
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/usr/local/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/usr/local/include -DXWINDOW
 
 # OPTFLAGS is normally -O0 for init
 OPTFLAGS = -O0 -g
diff --git a/bin/makefile-init-freebsd.x86_64 b/bin/makefile-init-freebsd.x86_64
index 2c3d9ce..8da5044 100644
--- a/bin/makefile-init-freebsd.x86_64
+++ b/bin/makefile-init-freebsd.x86_64
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/usr/local/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/usr/local/include -DXWINDOW
 
 # OPTFLAGS is normally -O0 for init
 OPTFLAGS = -O0 -g
diff --git a/bin/makefile-init-linux.x86_64 b/bin/makefile-init-linux.x86_64
index 3f64a50..8d696dd 100644
--- a/bin/makefile-init-linux.x86_64
+++ b/bin/makefile-init-linux.x86_64
@@ -14,7 +14,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2, for INIT we want unoptimized in case we need to debug it
 OPTFLAGS =  -O0 -g
diff --git a/bin/makefile-init-sunos5.sparc b/bin/makefile-init-sunos5.sparc
index 69f8997..b75871b 100644
--- a/bin/makefile-init-sunos5.sparc
+++ b/bin/makefile-init-sunos5.sparc
@@ -30,7 +30,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xrdopt.o \
 	$(OBJECTDIR)xwinman.o
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -g for MAKEINIT, as it needs debugging often.
 OPTFLAGS = -g3 -O0
@@ -41,7 +41,7 @@ OPTFLAGS = -g3 -O0
 
 DEBUGFLAGS = # -DSTACKCHECK -DFNSTKCHECK
 
-MACHINEFLAGS = -DOS5 -DUSE_DLPI -DLOCK_X_UPDATES
+MACHINEFLAGS = -DOS5 -DUSE_DLPI
 
 # The LDEINIT wants to have NOVERSION set, so we don't hang up on
 # any change-over in versions.
diff --git a/bin/makefile-linux.386-x b/bin/makefile-linux.386-x
index 37fb185..b25198d 100644
--- a/bin/makefile-linux.386-x
+++ b/bin/makefile-linux.386-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g3
diff --git a/bin/makefile-linux.aarch64-x b/bin/makefile-linux.aarch64-x
index c6db5f1..1f2f156 100644
--- a/bin/makefile-linux.aarch64-x
+++ b/bin/makefile-linux.aarch64-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xrdopt.o \
 	$(OBJECTDIR)xwinman.o
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g3
diff --git a/bin/makefile-linux.armv7l-x b/bin/makefile-linux.armv7l-x
index c6db5f1..1f2f156 100644
--- a/bin/makefile-linux.armv7l-x
+++ b/bin/makefile-linux.armv7l-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xrdopt.o \
 	$(OBJECTDIR)xwinman.o
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g3
diff --git a/bin/makefile-linux.x86_64-x b/bin/makefile-linux.x86_64-x
index 8129feb..f280cba 100644
--- a/bin/makefile-linux.x86_64-x
+++ b/bin/makefile-linux.x86_64-x
@@ -14,7 +14,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g3
diff --git a/bin/makefile-openbsd.x86_64-x b/bin/makefile-openbsd.x86_64-x
index 70a1798..b95e5f5 100644
--- a/bin/makefile-openbsd.x86_64-x
+++ b/bin/makefile-openbsd.x86_64-x
@@ -13,7 +13,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xwinman.o
 
 
-XFLAGS = -I/usr/X11R6/include -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -I/usr/X11R6/include -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g3
diff --git a/bin/makefile-sunos5.386-x b/bin/makefile-sunos5.386-x
index f1c7b78..22bedc6 100644
--- a/bin/makefile-sunos5.386-x
+++ b/bin/makefile-sunos5.386-x
@@ -22,7 +22,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xrdopt.o \
 	$(OBJECTDIR)xwinman.o
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g
@@ -36,7 +36,6 @@ DEBUGFLAGS = # -DSTACKCHECK -DFNSTKCHECK
 DFLAGS = $(XFLAGS) \
 	 $(DEBUGFLAGS) \
 	-DOS5 \
-	-DLOCK_X_UPDATES   \
 	-DRELEASE=351
 
 LDFLAGS = -L/usr/X11/lib -lX11 -lc -lm -lsocket -lnsl
diff --git a/bin/makefile-sunos5.i386-x b/bin/makefile-sunos5.i386-x
index 8831073..40005ea 100644
--- a/bin/makefile-sunos5.i386-x
+++ b/bin/makefile-sunos5.i386-x
@@ -22,7 +22,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xrdopt.o \
 	$(OBJECTDIR)xwinman.o
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g3
@@ -36,7 +36,6 @@ DEBUGFLAGS = # -DSTACKCHECK -DFNSTKCHECK
 DFLAGS = $(XFLAGS) \
 	$(DEBUGFLAGS) \
 	-DOS5 -DUSE_DLPI \
-	-DLOCK_X_UPDATES   \
 	-I$(OPENWINHOME)/include \
 	-DRELEASE=210
 
diff --git a/bin/makefile-sunos5.sparc-x b/bin/makefile-sunos5.sparc-x
index a9304cc..cca4965 100644
--- a/bin/makefile-sunos5.sparc-x
+++ b/bin/makefile-sunos5.sparc-x
@@ -29,7 +29,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xrdopt.o \
 	$(OBJECTDIR)xwinman.o
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g3
@@ -40,7 +40,7 @@ OPTFLAGS =  -O2 -g3
 
 DEBUGFLAGS = # -DSTACKCHECK -DFNSTKCHECK
 
-MACHINEFLAGS = -DOS5 -DUSE_DLPI -DLOCK_X_UPDATES
+MACHINEFLAGS = -DOS5 -DUSE_DLPI
 
 DFLAGS = $(XFLAGS) \
 	 $(DEBUGFLAGS) \
diff --git a/bin/makefile-sunos5.x86_64-x b/bin/makefile-sunos5.x86_64-x
index 3f8ab9f..8322b1b 100644
--- a/bin/makefile-sunos5.x86_64-x
+++ b/bin/makefile-sunos5.x86_64-x
@@ -22,7 +22,7 @@ XFILES = $(OBJECTDIR)xmkicon.o \
 	$(OBJECTDIR)xrdopt.o \
 	$(OBJECTDIR)xwinman.o
 
-XFLAGS = -DXWINDOW -DLOCK_X_UPDATES
+XFLAGS = -DXWINDOW
 
 # OPTFLAGS is normally -O2.
 OPTFLAGS =  -O2 -g
@@ -36,7 +36,6 @@ DEBUGFLAGS = # -DSTACKCHECK -DFNSTKCHECK
 DFLAGS = $(XFLAGS) \
 	 $(DEBUGFLAGS) \
 	-DOS5 \
-	-DLOCK_X_UPDATES   \
 	-DUSE_DLPI \
 	-DRELEASE=351
 
diff --git a/inc/keyeventdefs.h b/inc/keyeventdefs.h
index 69e69c3..b805988 100644
--- a/inc/keyeventdefs.h
+++ b/inc/keyeventdefs.h
@@ -1,7 +1,7 @@
 #ifndef KEYEVENTDEFS_H
 #define KEYEVENTDEFS_H 1
 #include <sys/types.h>
-void getsignaldata(int sig);
+void process_io_events();
 void kb_trans(u_short keycode, u_short upflg);
 void taking_mouse_down(void);
 void copy_cursor(int newx, int newy);
diff --git a/inc/version.h b/inc/version.h
index 869a2fa..63e883c 100644
--- a/inc/version.h
+++ b/inc/version.h
@@ -223,7 +223,6 @@ error Must specify RELEASE to build Medley.
 #ifdef OS5
 		/* Solaris, sort of SYSV-ish, but not really */
 #define MAIKO_ENABLE_ETHERNET
-#define LOCK_X_UPDATES 1
 #endif /* OS5 */
 
 
diff --git a/inc/xwinmandefs.h b/inc/xwinmandefs.h
index 4729897..b1ee029 100644
--- a/inc/xwinmandefs.h
+++ b/inc/xwinmandefs.h
@@ -8,5 +8,5 @@ void Set_BitGravity(XButtonEvent *event, DspInterface dsp, Window window, int gr
 void enable_Xkeyboard(DspInterface dsp);
 void disable_Xkeyboard(DspInterface dsp);
 void beep_Xkeyboard(DspInterface dsp);
-void getXsignaldata(DspInterface dsp);
+void process_Xevents(DspInterface dsp);
 #endif
diff --git a/src/keyevent.c b/src/keyevent.c
index 77e0eac..c7738ff 100644
--- a/src/keyevent.c
+++ b/src/keyevent.c
@@ -133,10 +133,6 @@ extern DLword *DisplayRegion68k;
 static struct timeval SelectTimeout = {0, 0};
 #endif /* DOS */
 
-#ifdef XWINDOW
-extern volatile sig_atomic_t Event_Req;
-#endif /* XWINDOW */
-
 extern MISCSTATS *MiscStats;
 LispPTR *LASTUSERACTION68k;
 LispPTR *CLastUserActionCell68k;
@@ -187,7 +183,7 @@ LispPTR *MOUSECHORDTICKS68k;
 /**NEW GLOBAL***-> will be moved***/
 LispPTR *KEYBOARDEVENTQUEUE68k;
 LispPTR *KEYBUFFERING68k;
-int KBDEventFlg = NIL;
+int KBDEventFlg = 0;
 DLword *CTopKeyevent;
 
 LispPTR DOBUFFEREDTRANSITION_index;
@@ -213,20 +209,12 @@ DLword ColorCursor_savebitmap[CURSORWIDTH / COLORPIXELS_IN_DLWORD * CURSORHEIGHT
 
 /************************************************************************/
 /*									*/
-/*			G E T S I G N A L D A T A			*/
-/*									*/
-/*	Handler for the SIGIO interrupt, which happens			*/
-/*		1. When a key transition happens			*/
-/*		2. On mouse moves					*/
-/*		3. When TCP input becomes available.			*/
-/*		4. When a NIT ethernet packet becomes available.	*/
-/*		5. When a console/log/stderr msg needs to be printed.	*/
-/*									*/
-/*									*/
-/*									*/
-/*									*/
-/*									*/
+/*			p r o c e s s _ i o _ e v e n t s		*/
 /*									*/
+/*	Periodically, or After a SIGIO interrupt which happens		*/
+/*		1. When TCP input becomes available.			*/
+/*		2. When a NIT ethernet packet becomes available.	*/
+/*		3. When a console/log/stderr msg needs to be printed.	*/
 /*									*/
 /*									*/
 /*	Statics:  LispReadFds	A 32-bit vector with a 1 for each	*/
@@ -256,49 +244,16 @@ DLword ColorCursor_savebitmap[CURSORWIDTH / COLORPIXELS_IN_DLWORD * CURSORHEIGHT
 /*									*/
 /************************************************************************/
 
-void getsignaldata(int sig)
+void process_io_events()
 {
 #ifndef DOS
-  fd_set rfds, efds;
+  fd_set rfds;
   u_int iflags;
   int i;
 
-#ifdef XWINDOW
-#if defined(sun)
-  if (Event_Req) {
-    if (!XLocked++)
-      getXsignaldata(currentdsp);
-    else
-      XNeedSignal = 1;
-    Event_Req = FALSE;
-    XLocked--;
-  }
-#endif
-#endif /* XWINDOW */
-
-  /* #ifndef KBINT */
-  /* FD_COPY would be preferred but uses deprecated bcopy() on macOS.  Why? */
   memcpy(&rfds, &LispReadFds, sizeof(rfds));
-  memcpy(&efds, &LispReadFds, sizeof(efds));
 
-/* label and ifs not needed if only keyboard on SIGIO */
-getmore:
-  if (select(32, &rfds, NULL, &efds, &SelectTimeout) >= 0)
-  {
-      /* need to print out fd sets...
-    DBPRINT(("SIGIO: fd mask(r/e) = 0x%x/0x%x.\n", rfds, efds));
-      */
-
-
-#ifdef XWINDOW
-    if (FD_ISSET(ConnectionNumber(currentdsp->display_id), &rfds)) {
-      if (!XLocked)
-        getXsignaldata(currentdsp);
-      else
-        XNeedSignal = 1;
-    }
-
-#endif /* XWINDOW */
+  if (select(32, &rfds, NULL, NULL, &SelectTimeout) > 0) {
 
 #ifdef MAIKO_ENABLE_ETHERNET
     if (ether_fd >= 0 && FD_ISSET(ether_fd, &rfds)) { /* Raw ethernet (NIT) I/O happened, so handle it. */
@@ -338,7 +293,7 @@ getmore:
   }
 /* #endif */
 #endif /* DOS */
-} /* end getsignaldata */
+} /* end process_io_events */
 
 
 /************************************************************************/
diff --git a/src/rs232c.c b/src/rs232c.c
index 0ceb13e..389e8a2 100644
--- a/src/rs232c.c
+++ b/src/rs232c.c
@@ -253,7 +253,7 @@ rs232c_read() {
       }
     } else {
       /*
-       * SIGIO handler getsignaldata and the successive
+       * SIGIO handler, process_io_events, and the successive
        * rs232c_read has been called before Lisp prepares
        * the next buffer.  Turn on RS232C_remain_data to
        * specify to read the remaining data after.
diff --git a/src/timer.c b/src/timer.c
index 7ae3132..5227c6a 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -87,9 +87,7 @@ extern DspInterface currentdsp;
 
 int TIMEOUT_TIME; /* For file system timeout */
 
-#ifdef XWINDOW
-volatile sig_atomic_t Event_Req = FALSE;
-#endif /* XWINDOW */
+volatile sig_atomic_t IO_Signalled = FALSE;
 
 static int gettime(int casep);
 
@@ -403,7 +401,7 @@ void update_timer() {
 /* TIMER_INTERVAL usec ~ 20  per second.  This should live in some
         machine-configuration
         file somewhere - it can be changed as the -t parameter to lisp*/
-int TIMER_INTERVAL = 25000;
+int TIMER_INTERVAL = 10000;
 
 extern int LispWindowFd;
 
@@ -423,10 +421,6 @@ static void int_timer_service(int sig)
 
   Irq_Stk_Check = 0;
   Irq_Stk_End = 0;
-
-#ifdef XWINDOW
-  Event_Req = TRUE;
-#endif
 }
 
 /************************************************************************/
@@ -466,7 +460,7 @@ static void int_timer_init()
 
   timer_action.sa_handler = int_timer_service;
   sigemptyset(&timer_action.sa_mask);
-  timer_action.sa_flags = 0;
+  timer_action.sa_flags = SA_RESTART;
 
   if (sigaction(SIGVTALRM, &timer_action, NULL) == -1) {
     perror("sigaction: SIGVTALRM");
@@ -496,15 +490,10 @@ void int_io_open(int fd)
 {
 #ifdef DOS
 /* would turn on DOS kbd signal handler here */
-#elif KBINT
-
+#elseif defined(O_ASYNC)
   DBPRINT(("int_io_opening %d\n", fd));
-  if (fcntl(fd, F_SETOWN, getpid()) == -1) {
-#ifdef DEBUG
-    perror("fcntl F_SETOWN ERROR");
-#endif
-  };
-  if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_ASYNC) == -1) perror("fcntl F_SETFL error");
+  if (fcntl(fd, F_SETOWN, getpid()) == -1) perror("fcntl F_SETOWN error");
+  if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_ASYNC) == -1) perror("fcntl F_SETFL on error");
 #endif
 }
 
@@ -512,11 +501,27 @@ void int_io_close(int fd)
 {
 #ifdef DOS
 /* Turn off signaller here */
-#elif KBINT
-  fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) & ~O_ASYNC);
+#elseif defined(O_ASYNC)
+  if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) & ~O_ASYNC) == -1) perror("fcntl_F_SETFL off error");
 #endif
 }
 
+/************************************************************************/
+/*									*/
+/*		    i n t _ i o _ s e r v i c e				*/
+/*									*/
+/*	Handle SIGIO							*/
+/*									*/
+/*									*/
+/************************************************************************/
+
+static void int_io_service(int sig)
+{
+  Irq_Stk_Check = 0;
+  Irq_Stk_End = 0;
+  IO_Signalled = TRUE;
+}
+
 /************************************************************************/
 /*									*/
 /*			i n t _ i o _ i n i t				*/
@@ -531,7 +536,7 @@ void int_io_close(int fd)
 static void int_io_init() {
 #ifndef DOS
   struct sigaction io_action;
-  io_action.sa_handler = getsignaldata;
+  io_action.sa_handler = int_io_service;
   sigemptyset(&io_action.sa_mask);
   io_action.sa_flags = 0;
 
@@ -541,11 +546,6 @@ static void int_io_init() {
     DBPRINT(("I/O interrupts enabled\n"));
   }
 
-#if defined(XWINDOW) && defined(I_SETSIG)
-  if (ioctl(ConnectionNumber(currentdsp->display_id), I_SETSIG, S_INPUT) < 0)
-    perror("ioctl on X fd - SETSIG for input handling failed");
-#endif
-
 #if defined(USE_DLPI)
   DBPRINT(("INIT ETHER:  Doing I_SETSIG.\n"));
   if (ether_fd > 0)
diff --git a/src/xc.c b/src/xc.c
index 8370243..c664c1a 100644
--- a/src/xc.c
+++ b/src/xc.c
@@ -99,6 +99,7 @@
 #include "ubf3defs.h"
 #include "unwinddefs.h"
 #include "vars3defs.h"
+#include "xwinmandefs.h"
 #include "z2defs.h"
 
 #ifdef DOS
@@ -108,6 +109,8 @@ extern IOPAGE *IOPage68K;
 extern KbdInterface currentkbd;
 extern DspInterface currentdsp;
 extern MouseInterface currentmouse;
+#else
+extern DspInterface currentdsp;
 #endif /* DOS */
 
 typedef struct conspage ConsPage;
@@ -141,11 +144,8 @@ register LispPTR tscache asm("bx");
 #define PVARL PVar
 #define IVARL IVar
 
-#ifdef XWINDOW
-extern volatile sig_atomic_t Event_Req;       /* != 0 when it's time to check X events
-                                                 on machines that don't get them reliably
-                                                 (e.g. Suns running OpenWindows) */
-#endif                /* XWINDOW */
+/* used by SIGIO signal handler to indicate I/O may be possible */
+extern volatile sig_atomic_t IO_Signalled;
 
 #ifdef PCTRACE
 /* For keeping a trace table (ring buffer) of 100 last PCs */
@@ -1112,17 +1112,22 @@ check_interrupt:
       Irq_Stk_End = (UNSIGNED)EndSTKP;
     }
 
-    /* Check for an IRQ request */
+    /* This is a good time to process keyboard/mouse and ethernet I/O
+     * X events are not managed in the async/SIGIO code while
+     * raw ethernet, serial port, and socket connections are.
+     * If the system is configured with SIGIO handling we have a hint
+     * that allows us to cheaply skip if there's nothing to do
+     */
+    process_Xevents(currentdsp);
+
+    if (IO_Signalled) {
+      IO_Signalled = FALSE;
+      process_io_events();
+    }
 
     if ((Irq_Stk_End <= 0) || (Irq_Stk_Check <= 0) || need_irq) {
       if (StkOffset_from_68K(CSTKPTR) > InterfacePage->stackbase) {
         /* Interrupts not Disabled */
-        /* XXX: what on earth is this code trying to accomplish by calling
-           getsignaldata
-        */
-#if !defined(KBINT) || defined(OS4)
-        getsignaldata(0);
-#endif
         EXT;
         update_timer();
 
diff --git a/src/xinit.c b/src/xinit.c
index d47c8d9..9d7d17b 100644
--- a/src/xinit.c
+++ b/src/xinit.c
@@ -30,6 +30,7 @@
 #include "adr68k.h"
 #include "xinitdefs.h"
 #include "dspifdefs.h"
+#include "timerdefs.h"
 #include "xbbtdefs.h"
 #include "xlspwindefs.h"
 #include "xwinmandefs.h"
@@ -65,7 +66,6 @@ Colormap Colors;
 
 volatile sig_atomic_t XLocked = 0; /* non-zero while doing X ops, to avoid signals */
 volatile sig_atomic_t XNeedSignal = 0; /* T if an X interrupt happened while XLOCK asserted */
-extern fd_set LispReadFds;
 
 /************************************************************************/
 /*									*/
@@ -108,10 +108,6 @@ void lisp_Xexit(DspInterface dsp)
 {
   assert(Lisp_Xinitialized);
 
-#if defined(I_SETSIG)
-  ioctl(ConnectionNumber(dsp->display_id), I_SETSIG, 0); /* so no interrupts happen during */
-#endif
-
   XLOCK;
   XDestroySubwindows(dsp->display_id, dsp->LispWindow);
   XDestroyWindow(dsp->display_id, dsp->LispWindow);
@@ -180,9 +176,6 @@ void Open_Display(DspInterface dsp)
 {
   assert(Lisp_Xinitialized == false);
 
-  FD_SET(ConnectionNumber(dsp->display_id), &LispReadFds);
-  fcntl(ConnectionNumber(dsp->display_id), F_SETOWN, getpid());
-
   /****************************************************/
   /* If debugging, set the X connection so that	*/
   /* we run synchronized--so a debugger can		*/
@@ -200,7 +193,7 @@ void Open_Display(DspInterface dsp)
 
   Create_LispWindow(dsp); /* Make the main window */
   Lisp_Xinitialized = true;
-  init_Xevent(dsp); /* Turn on the intrpts. */
+  init_Xevent(dsp); /* Turn on the event reporting */
 } /* end OpenDisplay */
 
 /*********************************************************************/
diff --git a/src/xlspwin.c b/src/xlspwin.c
index 55dddde..f4cc2b6 100644
--- a/src/xlspwin.c
+++ b/src/xlspwin.c
@@ -340,8 +340,8 @@ void DoRing() {
   KBEVENT *kbevent;
 
   TPRINT(("TRACE: DoRing()\n"));
-
 do_ring:
+  /* DEL is not generally present on a Mac X keyboard, Ctrl-shift-ESC would be 18496 */
   if (((*EmKbdAd268K) & 2113) == 0) { /*Ctrl-shift-NEXT*/
     error("******  EMERGENCY Interrupt ******");
     *EmKbdAd268K = KB_ALLUP;          /*reset*/
diff --git a/src/xwinman.c b/src/xwinman.c
index 39965b9..c88c29d 100644
--- a/src/xwinman.c
+++ b/src/xwinman.c
@@ -171,7 +171,7 @@ void beep_Xkeyboard(DspInterface dsp)
 
 /************************************************************************/
 /*									*/
-/*		    g e t X s i g n a l d a t a				*/
+/*		    p r o c e s s _ X e v e n t s			*/
 /*									*/
 /*  Take X key/mouse events and turn them into Lisp events		*/
 /*									*/
@@ -179,7 +179,7 @@ void beep_Xkeyboard(DspInterface dsp)
 
 extern int Current_Hot_X, Current_Hot_Y; /* Cursor hotspot */
 
-void getXsignaldata(DspInterface dsp)
+void process_Xevents(DspInterface dsp)
 {
   XEvent report;
 
@@ -193,8 +193,6 @@ void getXsignaldata(DspInterface dsp)
               (short)((report.xmotion.x + dsp->Visible.x) & 0xFFFF) - Current_Hot_X;
           *EmCursorY68K = (*((DLword *)EmMouseY68K)) =
               (short)((report.xmotion.y + dsp->Visible.y) & 0xFFFF) - Current_Hot_Y;
-          DoRing();
-          if ((KBDEventFlg) > 0) Irq_Stk_End = Irq_Stk_Check = 0;
           break;
         case KeyPress:
           kb_trans(SUNLispKeyMap[(report.xkey.keycode) - KEYCODE_OFFSET], FALSE);
@@ -342,4 +340,4 @@ void getXsignaldata(DspInterface dsp)
       Set_BitGravity(&report.xbutton, dsp, dsp->NWGrav, NorthWestGravity);
     XFlush(dsp->display_id);
   } /* end while */
-} /* end getXsignaldata() */
+} /* end process_Xevents */