diff --git a/libguile/ChangeLog b/libguile/ChangeLog
index f8a627cf8..38bc30167 100644
--- a/libguile/ChangeLog
+++ b/libguile/ChangeLog
@@ -1,3 +1,24 @@
+Mon Apr 28 06:10:14 1997  Gary Houston  <ghouston@actrix.gen.nz>
+
+	* async.c (scm_sys_tick_async_thunk): commented out.  I'm not
+	sure how this was supposed to work.
+	(scm_async_click): don't send SCM_TICK_SIGNAL.
+	(scm_init_async): don't initialize %tick-thunk.
+
+	* the following change doesn't affect the Scheme interface:
+ 	gc-thunk is called at the end of garbage collection.  however it's
+ 	no longer implemented by pretending it's a signal.
+	
+	* gc.c (scm_gc_end): don't call scm_take_signal.  instead mark the
+	system async corresponding to scm_gc_thunk.
+	* async.h: declare scm_gc_async.
+	* async.c (scm_sys_gc_async_thunk): apply the thunk named by
+	gc-thunk directly, instead of going through a signal handler.
+	(scm_gc_async): new variable, points to the GC system-async.
+	(scm_init_async): save the GC async as scm_gc_async instead
+	of using system_signal_asyncs.
+	(scm_gc_vcell): new variable, stores the gc-thunk vcell.
+
 Mon Apr 28 19:14:44 1997  Jim Blandy  <jimb@floss.cyclic.com>
 
 	* Makefile.am (libpath.h, cpp_err_symbols.c, cpp_sig_symbols.c):
diff --git a/libguile/async.c b/libguile/async.c
index 115cc8c2f..d49755c43 100644
--- a/libguile/async.c
+++ b/libguile/async.c
@@ -142,7 +142,15 @@ asyncs_pending ()
   return 0;
 }
 
-
+#if 0
+static SCM scm_sys_tick_async_thunk SCM_P ((void));
+static SCM
+scm_sys_tick_async_thunk ()
+{
+  scm_deliver_signal (SCM_TICK_SIGNAL);
+  return SCM_BOOL_F;
+}
+#endif
 
 void
 scm_async_click ()
@@ -221,8 +229,10 @@ scm_async_click ()
 	}
     }
 
-  if (owe_tick)
-    scm_async_mark (system_signal_asyncs[SCM_SIG_ORD(SCM_TICK_SIGNAL)]);
+  /* 
+     if (owe_tick)
+       scm_async_mark (system_signal_asyncs[SCM_SIG_ORD(SCM_TICK_SIGNAL)]);
+     */
 
   SCM_DEFER_INTS;
   if (scm_tick_rate && scm_switch_rate)
@@ -564,31 +574,29 @@ scm_sys_alrm_async_thunk ()
   return SCM_BOOL_F;
 }
 
+/* points to the GC system-async, so that scm_gc_end can find it.  */
+SCM scm_gc_async;
 
-static SCM scm_sys_gc_async_thunk SCM_P ((void));
+/* the vcell for gc-thunk.  */
+static SCM scm_gc_vcell;
 
+/* the thunk installed in the GC system-async, which is marked at the
+   end of garbage collection.  */
 static SCM
-scm_sys_gc_async_thunk ()
+scm_sys_gc_async_thunk (void)
 {
-  scm_deliver_signal (SCM_GC_SIGNAL);
-  return SCM_BOOL_F;
+  if (SCM_NFALSEP (scm_gc_vcell))
+    {
+      SCM proc = SCM_CDR (scm_gc_vcell);
+
+      if (SCM_NFALSEP (proc) && !SCM_UNBNDP (proc))
+	scm_apply (proc, SCM_EOL, SCM_EOL);
+    }
+  return SCM_UNSPECIFIED;
 }
 
-
-static SCM scm_sys_tick_async_thunk SCM_P ((void));
-
-static SCM
-scm_sys_tick_async_thunk ()
-{
-  scm_deliver_signal (SCM_TICK_SIGNAL);
-  return SCM_BOOL_F;
-}
-
-
-
 
 
-
 SCM
 scm_take_signal (n)
      int n;
@@ -636,7 +644,6 @@ scm_mask_signals ()
 
 
 
-
 void
 scm_init_async ()
 {
@@ -660,13 +667,16 @@ scm_init_async ()
   a_thunk = scm_make_gsubr ("%segv-thunk", 0, 0, 0, scm_sys_segv_async_thunk);
   system_signal_asyncs[SCM_SIG_ORD(SCM_SEGV_SIGNAL)] = scm_system_async (a_thunk);
 
-
+  scm_gc_vcell = scm_sysintern ("gc-thunk", SCM_BOOL_F);
   a_thunk = scm_make_gsubr ("%gc-thunk", 0, 0, 0, scm_sys_gc_async_thunk);
-  system_signal_asyncs[SCM_SIG_ORD(SCM_GC_SIGNAL)] = scm_system_async (a_thunk);
+  scm_gc_async = scm_system_async (a_thunk);
 
   /* Clock and PC driven conditions are given highest priority. */
-  a_thunk = scm_make_gsubr ("%tick-thunk", 0, 0, 0, scm_sys_tick_async_thunk);
-  system_signal_asyncs[SCM_SIG_ORD(SCM_TICK_SIGNAL)] = scm_system_async (a_thunk);
+  /*
+    a_thunk = scm_make_gsubr ("%tick-thunk", 0, 0, 0, scm_sys_tick_async_thunk);
+    system_signal_asyncs[SCM_SIG_ORD(SCM_TICK_SIGNAL)] = scm_system_async (a_thunk);
+    */
+
   a_thunk = scm_make_gsubr ("%alrm-thunk", 0, 0, 0, scm_sys_alrm_async_thunk);
   system_signal_asyncs[SCM_SIG_ORD(SCM_ALRM_SIGNAL)] = scm_system_async (a_thunk);
 
diff --git a/libguile/async.h b/libguile/async.h
index 217603ba6..80c02401d 100644
--- a/libguile/async.h
+++ b/libguile/async.h
@@ -50,7 +50,7 @@
 
 
 extern unsigned int scm_mask_ints;
-
+extern SCM scm_gc_async;
 
 
 extern void scm_async_click SCM_P ((void));
diff --git a/libguile/gc.c b/libguile/gc.c
index 9d434f33e..84d94b83d 100644
--- a/libguile/gc.c
+++ b/libguile/gc.c
@@ -377,7 +377,7 @@ scm_gc_end ()
 {
   scm_gc_rt = SCM_INUM (scm_get_internal_run_time ()) - scm_gc_rt;
   scm_gc_time_taken = scm_gc_time_taken + scm_gc_rt;
-  scm_take_signal (SCM_GC_SIGNAL);
+  scm_system_async_mark (scm_gc_async);
 }