summaryrefslogtreecommitdiffstatshomepage
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/mame/drivers/namcos22.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/src/mame/drivers/namcos22.c b/src/mame/drivers/namcos22.c
index 802c0c93c59..a73a9bcf14b 100644
--- a/src/mame/drivers/namcos22.c
+++ b/src/mame/drivers/namcos22.c
@@ -1598,8 +1598,11 @@ READ16_MEMBER(namcos22_state::namcos22_keycus_r)
// It works in combination with keycus_w, but not yet understood how.
// printf("Hit keycus offs %x mask %x PC=%x\n", offset, mem_mask, space.device().safe_pc());
-
+
// protection (not used for all games)
+ // note: some games will XOR this register against a magic value, but that doesn't mean
+ // that the magic value is the keycus id. For example dirtdash XORs against $2c79, but its
+ // keycus id is $01a2 evident from a simple compare.
switch (m_gametype)
{
case NAMCOS22_RIDGE_RACER2:
@@ -5622,7 +5625,8 @@ DRIVER_INIT_MEMBER(namcos22_state,propcycl)
{
UINT32 *ROM = (UINT32 *)memregion("maincpu")->base();
- /* patch out strange routine (uninitialized-eprom related?) */
+ // patch out strange routine (uninitialized-eeprom related?)
+ // maybe needs more accurate 28C64 eeprom device emulation
ROM[0x1992C/4] = 0x4e754e75;
/**