diff --git a/src/mame/drivers/ampex.cpp b/src/mame/drivers/ampex.cpp
index 2be5e8424bf..a3c1889053d 100644
--- a/src/mame/drivers/ampex.cpp
+++ b/src/mame/drivers/ampex.cpp
@@ -88,7 +88,7 @@ ROM_START( dialog80 )
 
 	ROM_REGION( 0x0200, "proms", 0 ) // unknown TI 16-pin DIPs
 	ROM_LOAD( "417129-010.u16",  0x0000, 0x0100, NO_DUMP )
-	ROM_LOAD( "417129-010.u87",  0x0100, 0x0200, NO_DUMP )
+	ROM_LOAD( "417129-010.u87",  0x0100, 0x0100, NO_DUMP )
 ROM_END
 
 COMP( 1980, dialog80, 0, 0, ampex, ampex, ampex_state, 0, "Ampex", "Dialogue 80", MACHINE_IS_SKELETON )