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#206 - Memory Initialization doesn't mirror other Apple //e //c models

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This commit is contained in:
michaelangel007 2014-07-15 12:37:04 -07:00
parent 27c4a0654b
commit b68f89ebff
2 changed files with 59 additions and 12 deletions
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67
source/Memory.cpp
View file

@ -1379,21 +1379,66 @@ void MemReset ()
int iByte;
if (g_eMemoryInitPattern == MIP_FF_FF_00_00)
{
for( iByte = 0x0000; iByte < 0xC000; )
{
memmain[ iByte++ ] = 0xFF;
memmain[ iByte++ ] = 0xFF;
// Memory is pseudo-initialized across various models of Apple ][ //e //c
// We chose a random one for nostalgia's sake
// To inspect:
// F2. Ctrl-F2. CALL-151, C050 C053 C057
// OR
// F2, Ctrl-F2, F7, HGR
srand (time(NULL));
g_eMemoryInitPattern = static_cast<MemoryInitPattern_e>( rand() % NUM_MIP );
if( g_eMemoryInitPattern == MIP_ZERO )
g_eMemoryInitPattern = MIP_FF_FF_00_00;
// Note: ODD 16-bit words are zero'd above...
iByte++;
iByte++;
}
switch( g_eMemoryInitPattern )
{
case MIP_FF_FF_00_00:
for( iByte = 0x0000; iByte < 0xC000; )
{
memmain[ iByte++ ] = 0xFF;
memmain[ iByte++ ] = 0xFF;
// Note: ODD 16-bit words are zero'd above...
iByte++;
iByte++;
}
break;
case MIP_FF_00_FULL_PAGE:
for( iByte = 0x0000; iByte < 0xC000; iByte += 512 )
{
memset( &memmain[ iByte ], 0xFF, 256 );
// exceptions: xx28: 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 )
{
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;
}
}
break;
case MIP_FF_00_HALF_PAGE:
for( iByte = 0x0000; iByte < 0xC000; iByte += 256 )
memset( &memmain[ iByte ], 0xFF, 128 );
break;
}
// https://github.com/AppleWin/AppleWin/issues/206
// On a real Apple the RNDL and RNDH are initialized to random values from a cold boot.
// Work-around for a cold-booting bug in "Pooyan" which expects RNDL and RNDH to be non-zero.
// TODO: Use MemReturnRandomData() ???
DWORD clock = timeGetTime(); // We can't use g_nCumulativeCycles as it will be zero on a fresh execution.
memmain[ 0x4E ] = (clock >> 0) & 0xFF;

4
source/Memory.h
View file

@ -16,7 +16,9 @@ enum MemoryInitPattern_e
{
MIP_ZERO
, MIP_FF_FF_00_00
, MIP_FF_00_FULL_PAGE
, MIP_00_FF_HALF_PAGE
, MIP_FF_00_HALF_PAGE
, NUM_MIP
};
extern MemoryInitPattern_e g_eMemoryInitPattern;