diff --git a/src/mess/layout/snmath.lay b/src/mess/layout/snmath.lay
index e84c2e9fdfb..ca1eb371aea 100644
--- a/src/mess/layout/snmath.lay
+++ b/src/mess/layout/snmath.lay
@@ -3,19 +3,18 @@
 
 <!-- define elements -->
 
-<!-- note: the TI Speak & Spell 14seg digits look different from MAME's default, most notably the right half is wider -->
-
 	<element name="digit" defstate="0">
 		<led14seg><color red="0.2" green="1.0" blue="0.85" /></led14seg>
 	</element>
 
-<!-- add our own for DP(display point) and the custom AP(apostrophe) segments -->
+<!-- add our own for DP(display point) and the CT(comma tail) segments -->
+<!-- MAME led16segsc won't do, since Speak & Math has them on the left side -->
 
 	<element name="lamp_dp" defstate="0">
 		<disk state="0"><color red="0.0235" green="0.1255" blue="0.1059" /></disk>
 		<disk state="1"><color red="0.2" green="1.0" blue="0.85" /></disk>
 	</element>
-	<element name="lamp_ap" defstate="0">
+	<element name="lamp_ct" defstate="0">
 		<rect state="0"><color red="0.0235" green="0.1255" blue="0.1059" /></rect>
 		<rect state="1"><color red="0.2" green="1.0" blue="0.85" /></rect>
 	</element>
@@ -25,41 +24,45 @@
 <!-- build screen -->
 
 	<view name="Internal Layout">
-		<bounds left="0" right="89" top="0" bottom="15" />
+		<bounds left="-1.5" right="99" top="0" bottom="15" />
 
-	<!-- 8 digits -->
+	<!-- 9 digits -->
 
 		<bezel name="digit0" element="digit"><bounds x="0" y="0" width="10" height="15" /></bezel>
-		<bezel name="lamp14" element="lamp_dp"><bounds x="9" y="13.5" width="1.5" height="1.5" /></bezel>
-		<bezel name="lamp15" element="lamp_ap"><bounds x="10.5" y="0" width="0.5" height="3.5" /></bezel>
+		<bezel name="lamp14" element="lamp_dp"><bounds x="-1.5" y="11" width="1.5" height="1.5" /></bezel>
+		<bezel name="lamp15" element="lamp_ct"><bounds x="-0.8" y="13.5" width="0.75" height="1.5" /></bezel>
 
 		<bezel name="digit1" element="digit"><bounds x="11" y="0" width="10" height="15" /></bezel>
-		<bezel name="lamp114" element="lamp_dp"><bounds x="20" y="13.5" width="1.5" height="1.5" /></bezel>
-		<bezel name="lamp115" element="lamp_ap"><bounds x="21.5" y="0" width="0.5" height="3.5" /></bezel>
+		<bezel name="lamp114" element="lamp_dp"><bounds x="9.5" y="11" width="1.5" height="1.5" /></bezel>
+		<bezel name="lamp115" element="lamp_ct"><bounds x="10.2" y="13.5" width="0.75" height="1.5" /></bezel>
 
 		<bezel name="digit2" element="digit"><bounds x="22" y="0" width="10" height="15" /></bezel>
-		<bezel name="lamp214" element="lamp_dp"><bounds x="31" y="13.5" width="1.5" height="1.5" /></bezel>
-		<bezel name="lamp215" element="lamp_ap"><bounds x="32.5" y="0" width="0.5" height="3.5" /></bezel>
+		<bezel name="lamp214" element="lamp_dp"><bounds x="20.5" y="11" width="1.5" height="1.5" /></bezel>
+		<bezel name="lamp215" element="lamp_ct"><bounds x="21.2" y="13.5" width="0.75" height="1.5" /></bezel>
 
 		<bezel name="digit3" element="digit"><bounds x="33" y="0" width="10" height="15" /></bezel>
-		<bezel name="lamp314" element="lamp_dp"><bounds x="42" y="13.5" width="1.5" height="1.5" /></bezel>
-		<bezel name="lamp315" element="lamp_ap"><bounds x="43.5" y="0" width="0.5" height="3.5" /></bezel>
+		<bezel name="lamp314" element="lamp_dp"><bounds x="31.5" y="11" width="1.5" height="1.5" /></bezel>
+		<bezel name="lamp315" element="lamp_ct"><bounds x="32.2" y="13.5" width="0.75" height="1.5" /></bezel>
 
 		<bezel name="digit4" element="digit"><bounds x="44" y="0" width="10" height="15" /></bezel>
-		<bezel name="lamp414" element="lamp_dp"><bounds x="53" y="13.5" width="1.5" height="1.5" /></bezel>
-		<bezel name="lamp415" element="lamp_ap"><bounds x="54.5" y="0" width="0.5" height="3.5" /></bezel>
+		<bezel name="lamp414" element="lamp_dp"><bounds x="42.5" y="11" width="1.5" height="1.5" /></bezel>
+		<bezel name="lamp415" element="lamp_ct"><bounds x="43.2" y="13.5" width="0.75" height="1.5" /></bezel>
 
 		<bezel name="digit5" element="digit"><bounds x="55" y="0" width="10" height="15" /></bezel>
-		<bezel name="lamp514" element="lamp_dp"><bounds x="64" y="13.5" width="1.5" height="1.5" /></bezel>
-		<bezel name="lamp515" element="lamp_ap"><bounds x="65.5" y="0" width="0.5" height="3.5" /></bezel>
+		<bezel name="lamp514" element="lamp_dp"><bounds x="53.5" y="11" width="1.5" height="1.5" /></bezel>
+		<bezel name="lamp515" element="lamp_ct"><bounds x="54.2" y="13.5" width="0.75" height="1.5" /></bezel>
 
 		<bezel name="digit6" element="digit"><bounds x="66" y="0" width="10" height="15" /></bezel>
-		<bezel name="lamp614" element="lamp_dp"><bounds x="75" y="13.5" width="1.5" height="1.5" /></bezel>
-		<bezel name="lamp615" element="lamp_ap"><bounds x="76.5" y="0" width="0.5" height="3.5" /></bezel>
+		<bezel name="lamp614" element="lamp_dp"><bounds x="64.5" y="11" width="1.5" height="1.5" /></bezel>
+		<bezel name="lamp615" element="lamp_ct"><bounds x="65.2" y="13.5" width="0.75" height="1.5" /></bezel>
 
 		<bezel name="digit7" element="digit"><bounds x="77" y="0" width="10" height="15" /></bezel>
-		<bezel name="lamp714" element="lamp_dp"><bounds x="86" y="13.5" width="1.5" height="1.5" /></bezel>
-		<bezel name="lamp715" element="lamp_ap"><bounds x="87.5" y="0" width="0.5" height="3.5" /></bezel>
+		<bezel name="lamp714" element="lamp_dp"><bounds x="75.5" y="11" width="1.5" height="1.5" /></bezel>
+		<bezel name="lamp715" element="lamp_ct"><bounds x="76.2" y="13.5" width="0.75" height="1.5" /></bezel>
+
+		<bezel name="digit8" element="digit"><bounds x="88" y="0" width="10" height="15" /></bezel>
+		<bezel name="lamp814" element="lamp_dp"><bounds x="86.5" y="11" width="1.5" height="1.5" /></bezel>
+		<bezel name="lamp815" element="lamp_ct"><bounds x="87.2" y="13.5" width="0.75" height="1.5" /></bezel>
 
 	</view>
 </mamelayout>