From a4bae75d2ae4ad722d22902edb8bc83038c4a166 Mon Sep 17 00:00:00 2001
From: michaelangel007 <testcraft@sharedcraft.com>
Date: Thu, 17 Jul 2014 20:42:19 -0700
Subject: [PATCH] Documented #206 existing and new -memclear options with "In
 Development" in History.txt

     -memclear 0 Initialize memory to zero
     -memclear 1 Initialize memory to random values
     -memclear 2 Initialize memory to 4 byte pattern: FF FF 00 00
     -memclear 3 Initialize memory to even pages FF, odd pages 00
     -memclear 4 Initialize memory to first half page 00, last half page FF
     -memclear 5 Initialize memory to first half page FF, last half page 00
     -memclear 6   Initialize memory to byte offset of page
                   (current memory address low byte)
     -memclear 7   Initialize memory to page address
                   (current memory address high byte)
---
 bin/History.txt   | 22 ++++++++++++++++++++++
 source/Memory.cpp | 34 +++++++++++++++++++++++++++++-----
 source/Memory.h   |  2 ++
 3 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/bin/History.txt b/bin/History.txt
index 9ec02394..e12d4128 100644
--- a/bin/History.txt
+++ b/bin/History.txt
@@ -13,6 +13,28 @@ Restrictions/bugs:
 - SSI263 emulation is very basic: there is no attempt to emulate rate, inflection or filters.
 - During Mockingboard playback, Speaker emulation isn't precise
 
+
+In Development:
+---------------
+Changes:
+. Added command line switch to specify the type of memory initialization pattern.
+    -memclear #
+  Where # ranges from 0 to 7.
+  i.e.
+     -memclear 0   Initialize memory to zero
+     -memclear 1   Initialize memory to random values
+     -memclear 2   Initialize memory to 4 byte pattern: FF FF 00 00
+     -memclear 3   Initialize memory to even pages FF, odd pages 00
+     -memclear 4   Initialize memory to first half page 00, last half page FF
+     -memclear 5   Initialize memory to first half page FF, last half page 00
+     -memclear 6   Initialize memory to byte offset of page
+                   (current memory address low byte)
+     -memclear 7   Initialize memory to page address
+                   (current memory address high byte)
+Fixed:
+. [Bug #206] Pooyan freezes due to RNDL/RNDH not initialized to non-zero values
+
+
 Latest:
 -------
 
diff --git a/source/Memory.cpp b/source/Memory.cpp
index 39d63e75..3231f292 100644
--- a/source/Memory.cpp
+++ b/source/Memory.cpp
@@ -1392,14 +1392,10 @@ void MemReset ()
 	//   F2, Ctrl-F2, F7, HGR
 	DWORD clock = getRandomTime();
 
-	if ((g_nMemoryClearType >= 0) && (g_nMemoryClearType != MIP_RANDOM))
+	if (g_nMemoryClearType >= 0)
 		g_eMemoryInitPattern = static_cast<MemoryInitPattern_e>(g_nMemoryClearType);
 	else // random
-	{
 		g_eMemoryInitPattern = static_cast<MemoryInitPattern_e>( clock % NUM_MIP );
-		if (g_eMemoryInitPattern == MIP_RANDOM) // Twice Lucky! Force a choice.
-			g_eMemoryInitPattern = MIP_FF_FF_00_00;
-	}
 
 	switch( g_eMemoryInitPattern )
 	{
@@ -1442,6 +1438,34 @@ void MemReset ()
 			for( iByte = 0x0000; iByte < 0xC000; iByte += 256 )
 				memset( &memmain[ iByte ], 0xFF, 128 );
 			break;
+
+		case MIP_RANDOM:
+			unsigned char random[ 256 + 4 ];
+			for( iByte = 0x0000; iByte < 0xC000; iByte += 256 )
+			{
+				for( int i = 0; i < 256; i++ )
+				{
+					clock = getRandomTime();
+					random[ i+0 ] ^= (clock >>  0) & 0xFF;
+					random[ i+1 ] ^= (clock >> 11) & 0xFF;
+				}
+
+				memcpy( &memmain[ iByte ], random, 256 );
+			}
+			break;
+
+		case MIP_PAGE_ADDRESS_LOW:
+			for( iByte = 0x0000; iByte < 0xC000; iByte++ )
+				memmain[ iByte ] = iByte & 0xFF;
+			break;
+
+		case MIP_PAGE_ADDRESS_HIGH:
+			for( iByte = 0x0000; iByte < 0xC000; iByte += 256 )
+				memset( &memmain[ iByte ], (iByte >> 8), 256 );
+			break;
+
+		default: // MIP_ZERO -- nothing to do
+			break;
 	}
 
 	// https://github.com/AppleWin/AppleWin/issues/206
diff --git a/source/Memory.h b/source/Memory.h
index 660bb2fc..eff65273 100644
--- a/source/Memory.h
+++ b/source/Memory.h
@@ -20,6 +20,8 @@ enum MemoryInitPattern_e
 	, MIP_FF_00_FULL_PAGE
 	, MIP_00_FF_HALF_PAGE
 	, MIP_FF_00_HALF_PAGE
+	, MIP_PAGE_ADDRESS_LOW
+	, MIP_PAGE_ADDRESS_HIGH
 	, NUM_MIP
 };
 extern MemoryInitPattern_e g_eMemoryInitPattern;