diff --git a/Makefile b/Makefile
index 33187583..236594a6 100644
--- a/Makefile
+++ b/Makefile
@@ -27,7 +27,7 @@ SRC = syseng sysen1 sysen2 sysen3 sysnet kshack dragon channa	\
       macsym lmcons dmcg hack hibou agb gt40 rug maeda ms kle aap common \
       fonts zork 11logo kmp info aplogo bkph bbn pdp11 chsncp sca music1 \
       moon teach ken lmio1 llogo a2deh chsgtv clib sys3 lmio turnip \
-      mits_s rab stan_k bs cstacy kp dcp2 -pics- victor imlac rjl mb
+      mits_s rab stan_k bs cstacy kp dcp2 -pics- victor imlac rjl mb lars
 DOC = info _info_ sysdoc sysnet syshst kshack _teco_ emacs emacs1 c kcc \
       chprog sail draw wl pc tj6 share _glpr_ _xgpr_ inquir mudman system \
       xfont maxout ucode moon acount alan channa fonts games graphs humor \
diff --git a/src/lars/3dcube.84 b/src/lars/3dcube.84
new file mode 100644
index 00000000..87525b4a
--- /dev/null
+++ b/src/lars/3dcube.84
@@ -0,0 +1,150 @@
+title 3DCUBE - Rotating 3D cube.
+a
+a=1
+b=2
+c=3
+d=4
+e=5
+t=6
+ptr=7
+x1=10
+y1=11
+x2=12
+y2=13
+p=17
+
+dstop==003000
+point==020000
+vecto==100000
+verti==200000
+
+define ssfix a,b
+	muli a,400
+	tsc a,a
+	ash a+1,-243+19.!b(a)
+termin
+
+define ifix a
+	push p,a+1
+	ssfix a,-19.
+	move a,a+1
+	pop p,a+1
+termin
+
+loc 42
+	;tsint
+
+loc 100
+
+start:	move p,[-pdllen,,pdl-1]
+
+	;Get the 340 started.
+	hrlzi a,dstop
+	movem a,dlist
+	.dstart [-dlen,,dlist-1]
+	 .lose
+
+loop:	movei a,3
+	.sleep a,
+	pushj p,draw
+	jrst loop
+
+draw:
+	move ptr,[442200,,dlist]
+	movei a,point+17	;Set intentity and scale, go to point mode.
+	idpb a,ptr
+
+	movei x1,512.
+	movei y1,512.
+
+	move a,[0.01]
+	fadrb a,angle
+	pushj p,cos
+	fmpr a,[500.0]
+	ifix a
+	movei x2,512.(a)
+
+	move a,angle
+	pushj p,sin
+	fmpr a,[300.0]
+	ifix a
+	movei y2,512.(a)
+	pushj p,line
+
+	movei a,400000
+	idpb a,ptr
+	movei a,dstop
+	idpb a,ptr
+	popj p,
+
+;Draw line from x1,y1 to x2,y2.
+;Expect point mode.  Clobber x1,x2,y1,y2.
+line:	sub x2,x1
+	sub y2,y1
+
+	caige x2,200
+	 camg x2,[-200]
+	  jrst divide
+	caige y2,200
+	 camg y2,[-200]
+	  jrst divide
+
+	tro x1,point			;Stay in point mode.
+	idpb x1,ptr			;Point mode, horizontal.
+	tro y1,verti+vecto
+	idpb y1,ptr			;Point mode, vertical.  Go to vector.
+	jumpge x2,line1
+	movns x2
+	tro x2,200			;Negate bit.
+line1:	jumpge y2,line2
+	movns y2
+	tro y2,200			;Negate bit.
+line2:	lsh y2,8.
+	ior x2,y2
+	tro x2,600000			;Escape bit, Intensify bit.
+	idpb x2,ptr
+	movei a,point
+	idpb a,ptr
+	popj p,
+
+divide:	push p,x1
+	push p,x2
+	push p,y1
+	push p,y2
+	ash x2,-1
+	ash y2,-1
+	addm x2,-3(p)
+	addm y2,-1(p)
+	subm x2,-2(p)
+	movns -2(p)
+	subm y2,(p)
+	movns (p)
+	add x2,x1
+	add y2,y1
+	pushj p,line
+	pop p,y2
+	pop p,y1
+	pop p,x2
+	pop p,x1
+	add x2,x1
+	add y2,y1
+	jrst line
+
+COS:	FADR A,[1.57079632679]
+SIN:	MOVM T,A
+	CAMG T,[.00017]
+	 POPJ P,
+	FDVRI A,(-3.0)
+	PUSHJ P,SIN
+	FMPR T,T
+	FSC T,2
+	FADRI T,(-3.0)
+	FMPRB A,T
+	POPJ P,
+
+angle:	0.0
+
+.vector pdl(pdllen==1000)
+.vector dlist(dlen==4000)	;Display list.
+
+end start