From ccb85b19f91b59d22475d4b8ab2225ff819c3e53 Mon Sep 17 00:00:00 2001
From: Olivier Galibert <galibert@pobox.com>
Date: Sat, 12 Dec 2020 11:00:36 +0100
Subject: [PATCH] marble: The slapstic seems to trigger on more than the
 banking zone.

---
 src/mame/drivers/atarisy1.cpp |  5 +++++
 src/mame/machine/slapstic.cpp | 10 +++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/mame/drivers/atarisy1.cpp b/src/mame/drivers/atarisy1.cpp
index cf99a47a4e0..4fdde89a957 100644
--- a/src/mame/drivers/atarisy1.cpp
+++ b/src/mame/drivers/atarisy1.cpp
@@ -2491,6 +2491,11 @@ void atarisy1_state::init_slapstic()
 	m_maincpu->space(AS_PROGRAM).install_readwrite_tap(0x80000, 0x87fff, 0, "slapstic",
 													   [this](offs_t offset, u16 &data, u16 mem_mask) { m_slapstic->tweak(offset >> 1); },
 													   [this](offs_t offset, u16 &data, u16 mem_mask) { m_slapstic->tweak(offset >> 1); });
+
+	// The slaptic seems to trigger on the whole rom, but that slows things down too much.  limit to the range marble madness actually needs
+	m_maincpu->space(AS_PROGRAM).install_readwrite_tap(0x2ff5a, 0x2ff5b, 0, "slapstic",
+													   [this](offs_t offset, u16 &data, u16 mem_mask) { logerror("!! %x\n", offset); m_slapstic->tweak(offset >> 1); },
+													   [this](offs_t offset, u16 &data, u16 mem_mask) { m_slapstic->tweak(offset >> 1); });
 }
 
 void atarisy1_state::init_marble()
diff --git a/src/mame/machine/slapstic.cpp b/src/mame/machine/slapstic.cpp
index 314769b5879..e090721248c 100644
--- a/src/mame/machine/slapstic.cpp
+++ b/src/mame/machine/slapstic.cpp
@@ -867,11 +867,16 @@ int atari_slapstic_device::tweak(offs_t offset)
 				break;
 
 			/* ALTERNATE1 state: look for alternate2 offset, or else fall back to ENABLED */
+			/* Can also go to ADDITIVE1.  Not a hack, it's real. */
 			case ALTERNATE1:
 				if (MATCHES_MASK_VALUE(offset, slapstic.alt2))
 				{
 					state = ALTERNATE2;
 				}
+				else if (MATCHES_MASK_VALUE(offset, slapstic.add1))
+				{
+					state = ADDITIVE1;
+				}
 				else
 				{
 					state = ENABLED;
@@ -994,10 +999,9 @@ int atari_slapstic_device::tweak(offs_t offset)
 				}
 				break;
 
-			/* ADDITIVE3 state: waiting for a bank to seal the deal */
+			/* ADDITIVE3 state: waiting for the commit, which is common with alt, but can be delayed */
 			case ADDITIVE3:
-				if (offset == slapstic.bank[0] || offset == slapstic.bank[1] ||
-					offset == slapstic.bank[2] || offset == slapstic.bank[3])
+				if (MATCHES_MASK_VALUE(offset, slapstic.alt4))
 				{
 					state = DISABLED;
 					current_bank = add_bank;