diff --git a/src/sysen1/crock.1009 b/src/sysen1/crock.1010
old mode 100755
new mode 100644
similarity index 96%
rename from src/sysen1/crock.1009
rename to src/sysen1/crock.1010
index b6a90a4c..045d24fd
--- a/src/sysen1/crock.1009
+++ b/src/sysen1/crock.1010
@@ -64,6 +64,13 @@ ifn 20x,{
 
 ifn tnx,	oldmod:	0
 
+ifn its,{
+zz==.
+loc 42
+	tsint
+loc zz
+}
+
 pdl:	-40,,pdl
 	block 40
 
@@ -127,6 +134,8 @@ ifn tnx,[
 	MOVE T,[HPOSH,,HPOSH+1]
 	BLT T,EPOS
 
+ifn its, .suset [.smask,,[%pidwn]]	; Request interrupt when ITS revived.
+
 	; Start a new clock picture here
 LOOP:
 ifn its,[		; Get ITS time into H,M,S
@@ -239,6 +248,25 @@ ifn t%vt52, hrroi 2,[asciz "Y7 K"]
 	haltf
 	jrst crock
 ]
+
+ifn its,{
+tsint:	0
+	0
+	push p,a
+	.dietim a,
+	jumpl a,restart		; -1 means ITS revived.
+	pop p,a
+	.dismis tsint+1
+
+restart:
+	movei a,60.		; Short sleep to let DDT print ITS Revived!
+	.sleep a,
+	move a,[^P]   	; Clear screen.
+	.iot ttyc,a
+	move a,["C]
+	.iot ttyc,a
+	jrst crock		; Redraw.
+}
 
 ; Super hairy hand drawer.
 ; Inputs are: