diff --git a/src/mame/drivers/model2.c b/src/mame/drivers/model2.c
index 645e8b9a030..0fd53aab4a5 100644
--- a/src/mame/drivers/model2.c
+++ b/src/mame/drivers/model2.c
@@ -4035,9 +4035,9 @@ ROM_START( rchase2 ) /* Rail Chase 2 Revision A, Model 2B. Sega game ID# 833-118
 	ROM_LOAD("mpr-18029.32", 0x0000000, 0x200000, CRC(f6804150) SHA1(ef40c11008c75d04159772ad30f02cdb8c5464f3) )
 	ROM_LOAD("mpr-18030.34", 0x0400000, 0x200000, CRC(1167615d) SHA1(bae0060aec3c15f08342f11df665c05c5703523d) )
 
-	/* the Drive I/O clearly has a CPU on it (see above) */
-	ROM_REGION( 0x1000, "iocpu", 0 )
-	ROM_LOAD("epr-17895", 0x0000, 0x1000, NO_DUMP ) /* Z80 code, unknown rom size */
+	/* Z80 code located on the I/O board type 837-11694. Z80 @ 4Mhz with 8-way DSW & unknown SONY CXD10950 QFP64 chip */
+	ROM_REGION( 0x8000, "iocpu", 0 )
+	ROM_LOAD("epr-17895.ic8", 0x0000, 0x8000, CRC(8fd7003d) SHA1(b8b16e20e3ed07326330ba335ea1e701cc0bec17) )
 ROM_END