From 5e32a2dec80632f96fb37ee85c18e6173e60eeb7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20Banaan=20Ananas?=
 <happppp@users.noreply.github.com>
Date: Fri, 14 Feb 2014 02:38:13 +0000
Subject: [PATCH] fix addc subc zeroflag

---
 src/emu/cpu/mn10200/mn10200.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/emu/cpu/mn10200/mn10200.c b/src/emu/cpu/mn10200/mn10200.c
index 161f5de0380..cc5f1155def 100644
--- a/src/emu/cpu/mn10200/mn10200.c
+++ b/src/emu/cpu/mn10200/mn10200.c
@@ -904,13 +904,21 @@ void mn10200_device::execute_run()
 
 		// addc dn, dm
 		case 0x80:
+		{
+			UINT16 mask0 = ~FLAG_ZF | (m_psw & FLAG_ZF);
 			m_d[op&3] = do_add(m_d[op&3], m_d[op>>2&3], (m_psw & FLAG_CF) ? 1 : 0);
+			m_psw &= mask0; // ZF can only be set if it was set before the operation
 			break;
+		}
 
 		// subc dn, dm
 		case 0x90:
+		{
+			UINT16 mask0 = ~FLAG_ZF | (m_psw & FLAG_ZF);
 			m_d[op&3] = do_sub(m_d[op&3], m_d[op>>2&3], (m_psw & FLAG_CF) ? 1 : 0);
+			m_psw &= mask0; // ZF can only be set if it was set before the operation
 			break;
+		}
 
 		// add an, dm
 		case 0xc0:
@@ -1169,6 +1177,7 @@ void mn10200_device::execute_run()
 
 		// mov an, (abs24)
 		case 0x50: case 0x51: case 0x52: case 0x53:
+			m_cycles -= 1;
 			write_mem24(read_arg24(m_pc), m_a[op&3]);
 			break;