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Fix //c cold start memory 'blaster' initialization pattern

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This commit is contained in:
michaelangel007 2014-07-15 20:55:28 -07:00
parent b68f89ebff
commit 5109fd39da
1 changed files with 12 additions and 10 deletions
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22
source/Memory.cpp
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@ -1409,25 +1409,27 @@ void MemReset ()
{
memset( &memmain[ iByte ], 0xFF, 256 );
// exceptions: xx28: 00 Apple //e Platinum NTSC
// Exceptions: xx28: 00 xx68:00 Apple //e Platinum NTSC
memmain[ iByte + 0x28 ] = 0x00;
memmain[ iByte + 0x68 ] = 0x00;
}
break;
case MIP_00_FF_HALF_PAGE:
for( iByte = 0x0080; iByte < 0xC000; iByte += 256 )
for( iByte = 0x0080; iByte < 0xC000; iByte += 256 ) // NB. start = 0x80, delta = 0x100 !
{
memset( &memmain[ iByte ], 0xFF, 128 );
// exceptions: 2014: 1 1 2416:1 1 2818:1 1
// Note: the //c cold start 'blast' is partially emulated
if( iByte >= 0x2000 )
{
int iBlastAddr = (iByte / 0x200) + (iByte / 0x400); // TODO: Fix calculation
memmain[ iByte - 0x81 + iBlastAddr + 0 ] |= 0xC0;
memmain[ iByte - 0x81 + iBlastAddr + 1 ] |= 0xC0;
}
// Exceptions: Emulate the //c cold start memory 'blaster' pattern
// 2010: C0 C0 2111:C0 C0
// 2414: C0 C0 2515:C0 C0
// 2818: C0 C0 2919:C0 C0
// etc.
int iBase = iByte - 0x80;
int iPage = iBase & 0x1FFF;
int iAddr = 0x10 + (iPage / 0x100);
memmain[ iBase + iAddr + 0 ] |= 0xC0;
memmain[ iBase + iAddr + 1 ] |= 0xC0;
}
break;