diff --git a/src/mame/drivers/bzone.cpp b/src/mame/drivers/bzone.cpp
index f35d0a23888..e101e5182c1 100644
--- a/src/mame/drivers/bzone.cpp
+++ b/src/mame/drivers/bzone.cpp
@@ -669,7 +669,7 @@ ROM_START( bzone ) /* Analog Vec Gen A035742-02 */
 	ROM_LOAD( "036409-01.n1",  0x7800, 0x0800, CRC(1e14e919) SHA1(448fab30535e6fad7e0ab4427bc06bbbe075e797) )
 	/* Vector Generator ROMs */
 	ROM_LOAD( "036422-01.bc3", 0x3000, 0x0800, CRC(7414177b) SHA1(147d97a3b475e738ce00b1a7909bbd787ad06eda) )
-	ROM_LOAD( "036421-01.a3",  0x3800, 0x0800, CRC(8ea8f939) SHA1(b71e0ab0e220c3e64dc2b094c701fb1a960b64e4) )
+	ROM_LOAD( "036421-01.a3",  0x3800, 0x0800, CRC(8ea8f939) SHA1(b71e0ab0e220c3e64dc2b094c701fb1a960b64e4) )  // 036421-01e.a3 same contents
 
 	/* AVG PROM */
 	ROM_REGION( 0x100, "user1", 0 )
@@ -699,7 +699,7 @@ ROM_START( bzonea ) /* Analog Vec Gen A035742-02 */
 	ROM_LOAD( "036409-01.n1",  0x7800, 0x0800, CRC(1e14e919) SHA1(448fab30535e6fad7e0ab4427bc06bbbe075e797) )
 	/* Vector Generator ROMs */
 	ROM_LOAD( "036422-01.bc3", 0x3000, 0x0800, CRC(7414177b) SHA1(147d97a3b475e738ce00b1a7909bbd787ad06eda) )
-	ROM_LOAD( "036421-01.a3",  0x3800, 0x0800, CRC(8ea8f939) SHA1(b71e0ab0e220c3e64dc2b094c701fb1a960b64e4) )
+	ROM_LOAD( "036421-01.a3",  0x3800, 0x0800, CRC(8ea8f939) SHA1(b71e0ab0e220c3e64dc2b094c701fb1a960b64e4) )  // 036421-01e.a3 same contents
 
 	/* AVG PROM */
 	ROM_REGION( 0x100, "user1", 0 )