diff --git a/src/mame/drivers/model3.c b/src/mame/drivers/model3.c
index 2f803fb75dd..7028483c87b 100644
--- a/src/mame/drivers/model3.c
+++ b/src/mame/drivers/model3.c
@@ -4607,7 +4607,7 @@ ROM_START( magtruck )	/* Step 2.1 */
 ROM_END
 
 ROM_START( oceanhun )	/* Step 2.0   317-0244-COM security chip (837-13666-com security board) */
-	ROM_REGION64_BE( 0x4800000, "user1", 0 ) /* program + data ROMs */
+	ROM_REGION64_BE( 0x8800000, "user1", 0 ) /* program + data ROMs */
 	// CROM
 	ROM_LOAD64_WORD_SWAP( "epr21114.17", 0x000006, 0x200000, CRC(3adfcb9d) SHA1(22307e36a48e59ab881d6df2fbf2864f6a8b239c) )
 	ROM_LOAD64_WORD_SWAP( "epr21115.18", 0x000004, 0x200000, CRC(0bb9c107) SHA1(9778b9d020669a5f5736c80e77f0fb1c7d0e1f1b) )
@@ -4615,22 +4615,22 @@ ROM_START( oceanhun )	/* Step 2.0   317-0244-COM security chip (837-13666-com se
 	ROM_LOAD64_WORD_SWAP( "epr21117.20", 0x000000, 0x200000, CRC(58d985f1) SHA1(1a3376906212a8a3bfb196ea29b5e4455a30e8f2) )
 
 	// CROM1
-	ROM_LOAD64_WORD_SWAP( "mpr21082.5",  0x1800006, 0x400000, CRC(5bfeaa64) SHA1(3aa9f0b10c17e999dc917e3ff888887f42c54d31) )
-	ROM_LOAD64_WORD_SWAP( "mpr21083.6",  0x1800004, 0x400000, CRC(667e236f) SHA1(a3354a72ba3f535cbe54af592eafda1a9816a6e6) )
-	ROM_LOAD64_WORD_SWAP( "mpr21084.7",  0x1800002, 0x400000, CRC(36d5c4c1) SHA1(827590934023313e006330c66fe69763559effae) )
-	ROM_LOAD64_WORD_SWAP( "mpr21085.8",  0x1800000, 0x400000, CRC(8d62406a) SHA1(d8be8a7bf6f8c48c07a5532f772101888e65f9d4) )
+	ROM_LOAD64_WORD_SWAP( "mpr21082.5",  0x1800006, 0x800000, CRC(5056ad33) SHA1(b8aa4edcf6ae78f23ee1c6c02a9d5aef9c4e2eda) )
+	ROM_LOAD64_WORD_SWAP( "mpr21083.6",  0x1800004, 0x800000, CRC(fdec6a23) SHA1(88abe005c7f5f8423aa62ebc741e0b132b3a1fef) )
+	ROM_LOAD64_WORD_SWAP( "mpr21084.7",  0x1800002, 0x800000, CRC(c1c6b554) SHA1(596059872c0bbe39a78425cefe8cd2e17aa4b1ee) )
+	ROM_LOAD64_WORD_SWAP( "mpr21085.8",  0x1800000, 0x800000, CRC(2b7224d3) SHA1(195fb6eeaef6f2c66e780cc844d3d69ea587269b) )
 
 	// CROM2
-	ROM_LOAD64_WORD_SWAP( "mpr21086.9",  0x2800006, 0x400000, CRC(1e704e51) SHA1(970f19521aea6802276f46a20b39d23f23e09b84) )
-	ROM_LOAD64_WORD_SWAP( "mpr21087.10", 0x2800004, 0x400000, CRC(5db59035) SHA1(6e511e1819a48ca4d437587f3c9a14dc530352fe) )
-	ROM_LOAD64_WORD_SWAP( "mpr21088.11", 0x2800002, 0x400000, CRC(7730742b) SHA1(267444812a07ff4cf69da8545d4a7a2de1a3ba29) )
-	ROM_LOAD64_WORD_SWAP( "mpr21089.12", 0x2800000, 0x400000, CRC(a74d2dcb) SHA1(449a188a7e5a21e2b51748cf7ceae84e2e3beab4) )
+	ROM_LOAD64_WORD_SWAP( "mpr21086.9",  0x2800006, 0x800000, CRC(3f12e1d0) SHA1(739347a6c51350b686124511be477cb5d643c0b9) )
+	ROM_LOAD64_WORD_SWAP( "mpr21087.10", 0x2800004, 0x800000, CRC(cff28641) SHA1(8982b39b71f95f8db0d599be41fb8592210be779) )
+	ROM_LOAD64_WORD_SWAP( "mpr21088.11", 0x2800002, 0x800000, CRC(7ed71c8c) SHA1(642b6e81f5e532afa972b47df3ba451829bfd591) )
+	ROM_LOAD64_WORD_SWAP( "mpr21089.12", 0x2800000, 0x800000, CRC(2e8f88bd) SHA1(468c5e1d6596c8247ba94c02f6e519a091a78506) )
 
 	// CROM3
-	ROM_LOAD64_WORD_SWAP( "mpr21090.13", 0x3800006, 0x400000, CRC(7a95c388) SHA1(9a0f8b4e3bf0670d4f838a6fb18f29f5e1b3721b) )
-	ROM_LOAD64_WORD_SWAP( "mpr21091.14", 0x3800004, 0x400000, CRC(4031b961) SHA1(0c663171f15dea67709e7ffc3f45b7571e745232) )
-	ROM_LOAD64_WORD_SWAP( "mpr21092.15", 0x3800002, 0x400000, CRC(0ce200d9) SHA1(dd27ee6754df1330544a61ca6ec1ec2e79d11284) )
-	ROM_LOAD64_WORD_SWAP( "mpr21093.16", 0x3800000, 0x400000, CRC(6eae1fc4) SHA1(e83671d1ba7bcc8c8a577c725b54b7caa2e3666e) )
+	ROM_LOAD64_WORD_SWAP( "mpr21090.13", 0x3800006, 0x800000, CRC(749d7979) SHA1(20e6d318cbdbefc84002111336cc336143c7b757) )
+	ROM_LOAD64_WORD_SWAP( "mpr21091.14", 0x3800004, 0x800000, CRC(10671951) SHA1(1eeb5cded07380c06aca29379f3683977679c22b) )
+	ROM_LOAD64_WORD_SWAP( "mpr21092.15", 0x3800002, 0x800000, CRC(5b1ced40) SHA1(d1946563215797df1e6e71ee1a92f70a59a60392) )
+	ROM_LOAD64_WORD_SWAP( "mpr21093.16", 0x3800000, 0x800000, CRC(bdfbf357) SHA1(e324bbbc0ad17f365879c8be085ccde365445dd9) )
 
 	ROM_REGION( 0x2000000, "user3", 0 )  /* Video ROMs Part 1 */
 	ROM_LOAD_VROM( "mpr21098.26",  0x000002, 0x400000, CRC(91e71855) SHA1(d3dcea5e983b3a9139e0091a13e3f4b2764417b8) )