diff --git a/src/mame/drivers/rbmk.cpp b/src/mame/drivers/rbmk.cpp
index e462f197e72..b310919023e 100644
--- a/src/mame/drivers/rbmk.cpp
+++ b/src/mame/drivers/rbmk.cpp
@@ -607,8 +607,6 @@ void rbmk_state::rbspm(machine_config &config)
 	rbmk(config);
 	m_maincpu->set_addrmap(AS_PROGRAM, &rbmk_state::rbspm_mem);
 
-	m_mcu->set_disable(); // until decapped
-
 	// PIC16F84 but no CPU core available
 }
 
@@ -648,7 +646,7 @@ ROM_START( rbspm )
 	ROM_LOAD( "mj-dfmj-p1.bin", 0x00000, 0x80000, CRC(8f81f154) SHA1(50a9a373dec96b0265907f053d068d636bdabd61) )
 
 	ROM_REGION( 0x1000, "mcu", 0 ) /* protected MCU */
-	ROM_LOAD( "89c51.bin", 0x0000, 0x1000, NO_DUMP ) // reads as all 0xff
+	ROM_LOAD( "mj-dfmj_at89c51.bin", 0x0000, 0x1000, CRC(c6c48161) SHA1(c3ecf998820d758286b18896ff7860221dd0cf43) ) // decapped
 
 	ROM_REGION( 0x880, "pic", 0 ) /* pic was populated on this board */
 	ROM_LOAD( "c016_pic16f84_code.bin", 0x000, 0x800, CRC(1eb5cd2b) SHA1(9e747235e39eaea337f9325fa55fbfec1c03168d) )