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Second pass at 4A50 bankswitch support. This time it actually works
on all but one of the test ROMs I have :) Thanks must go to Eckhard Stolberg, who did about 95% of the work on this scheme. git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@1400 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba
This commit is contained in:
stephena
parent
03cd7ea291
commit
c1f887f731
@ -13,7 +13,7 @@
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// See the file "license" for information on usage and redistribution of
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// this file, and for a DISCLAIMER OF ALL WARRANTIES.
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//
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// $Id: Cart4A50.cxx,v 1.11 2008-02-21 16:11:15 stephena Exp $
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// $Id: Cart4A50.cxx,v 1.12 2008-02-21 23:58:09 stephena Exp $
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//============================================================================
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#include <cassert>
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@ -39,9 +39,7 @@ Cartridge4A50::Cartridge4A50(const uInt8* image, uInt32 size)
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// Initialize RAM with random values
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class Random random;
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for(uInt32 i = 0; i < 32768; ++i)
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{
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myRAM[i] = random.next();
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}
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}
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// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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@ -99,7 +97,7 @@ uInt8 Cartridge4A50::peek(uInt16 address)
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else if(!(lowAddress & 0x200))
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value = mySystem->tia().peek(address);
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checkBankSwitch(address);
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checkBankSwitch(address, value);
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}
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else
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{
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@ -111,17 +109,17 @@ uInt8 Cartridge4A50::peek(uInt16 address)
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else if(((address & 0x1fff) >= 0x1800) && // 1.5K region from 0x1800 - 0x1dff
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((address & 0x1fff) <= 0x1dff))
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{
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value = myIsRomMiddle ? myImage[(address & 0x7ff) + mySliceMiddle]
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value = myIsRomMiddle ? myImage[(address & 0x7ff) + mySliceMiddle + 0x10000]
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: myRAM[(address & 0x7ff) + mySliceMiddle];
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}
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else if((address & 0x1f00) == 0x1e00) // 256B region from 0x1e00 - 0x1eff
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{
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value = myIsRomHigh ? myImage[(address & 0xff) + mySliceHigh]
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value = myIsRomHigh ? myImage[(address & 0xff) + mySliceHigh + 0x10000]
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: myRAM[(address & 0xff) + mySliceHigh];
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}
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else if((address & 0x1f00) == 0x1f00) // 256B region from 0x1f00 - 0x1fff
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{
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value = myImage[(address & 0xff) + 0xff00];
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value = myImage[(address & 0xff) + 0x1ff00];
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if(((myLastData & 0xe0) == 0x60) &&
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((myLastAddress >= 0x1000) || (myLastAddress < 0x200)))
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mySliceHigh = (mySliceHigh & 0xf0ff) | ((address & 0x8) << 8) |
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@ -146,7 +144,7 @@ void Cartridge4A50::poke(uInt16 address, uInt8 value)
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else if(!(lowAddress & 0x200))
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mySystem->tia().poke(address, value);
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checkBankSwitch(address);
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checkBankSwitch(address, value);
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}
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else
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{
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@ -174,13 +172,12 @@ void Cartridge4A50::poke(uInt16 address, uInt8 value)
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((address & 0x70) << 4);
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}
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}
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myLastData = value;
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myLastAddress = address & 0x1fff;
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}
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// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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void Cartridge4A50::checkBankSwitch(uInt16 address)
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void Cartridge4A50::checkBankSwitch(uInt16 address, uInt8 value)
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{
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// This scheme contains so many hotspots that it's easier to just check
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// all of them
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@ -237,46 +234,49 @@ void Cartridge4A50::checkBankSwitch(uInt16 address)
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}
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}
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uInt8 databus = mySystem->getDataBusState();
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// Handle hotspots that mirror TIA or RIOT
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if((address >= 0x80) && (address < 0x100))
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{
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// Zero-page hotspots for upper page
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// 0xf4, 0xf6, 0xfc, 0xfe for ROM
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// 0xf5, 0xf7, 0xfd, 0xff for RAM
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// 0x74 - 0x7f (0x80 bytes lower)
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if((address & 0xf75) == 0x74) // Enable 256B of ROM at 0x1e00 - 0x1eff
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{
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myIsRomHigh = true;
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mySliceHigh = value << 8;
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}
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else if((address & 0xf75) == 0x75) // Enable 256B of RAM at 0x1e00 - 0x1eff
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{
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myIsRomHigh = false;
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mySliceHigh = (value & 0x7f) << 8;
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}
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// Zero-page hotspots for upper page
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// 0xf4, 0xf6, 0xfc, 0xfe for ROM
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// 0xf5, 0xf7, 0xfd, 0xff for RAM
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// 0x74 - 0x7f (0x80 bytes lower)
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if((address & 0xf75) == 0x74) // Enable 256B of ROM at 0x1e00 - 0x1eff
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{
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myIsRomHigh = true;
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mySliceHigh = databus << 8;
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}
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else if((address & 0xf75) == 0x75) // Enable 256B of RAM at 0x1e00 - 0x1eff
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{
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myIsRomHigh = false;
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mySliceHigh = (databus & 0x7f) << 8;
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}
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// Zero-page hotspots for lower and middle blocks
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// 0xf8, 0xf9, 0xfa, 0xfb
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// 0x78, 0x79, 0x7a, 0x7b (0x80 bytes lower)
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else if((address & 0xf7c) == 0x78)
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{
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if((databus & 0xf0) == 0) // Enable 2K of ROM at 0x1000 - 0x17ff
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// Zero-page hotspots for lower and middle blocks
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// 0xf8, 0xf9, 0xfa, 0xfb
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// 0x78, 0x79, 0x7a, 0x7b (0x80 bytes lower)
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else if((address & 0xf7c) == 0x78)
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{
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myIsRomLow = true;
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mySliceLow = (databus & 0xf) << 11;
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}
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else if((databus & 0xf0) == 0x40) // Enable 2K of RAM at 0x1000 - 0x17ff
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{
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myIsRomLow = false;
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mySliceLow = (databus & 0xf) << 11;
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}
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else if((databus & 0xf0) == 0x90) // Enable 1.5K of ROM at 0x1800 - 0x1dff
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{
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myIsRomMiddle = true;
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mySliceMiddle = ((databus & 0xf) | 0x10) << 11;
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}
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else if((databus & 0xf0) == 0xc0) // Enable 1.5K of RAM at 0x1800 - 0x1dff
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{
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myIsRomMiddle = false;
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mySliceMiddle = (databus & 0xf) << 11;
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if((value & 0xf0) == 0) // Enable 2K of ROM at 0x1000 - 0x17ff
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{
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myIsRomLow = true;
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mySliceLow = (value & 0xf) << 11;
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}
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else if((value & 0xf0) == 0x40) // Enable 2K of RAM at 0x1000 - 0x17ff
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{
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myIsRomLow = false;
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mySliceLow = (value & 0xf) << 11;
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}
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else if((value & 0xf0) == 0x90) // Enable 1.5K of ROM at 0x1800 - 0x1dff
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{
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myIsRomMiddle = true;
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mySliceMiddle = ((value & 0xf) | 0x10) << 11;
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}
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else if((value & 0xf0) == 0xc0) // Enable 1.5K of RAM at 0x1800 - 0x1dff
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{
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myIsRomMiddle = false;
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mySliceMiddle = (value & 0xf) << 11;
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}
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}
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}
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}
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@ -297,19 +297,19 @@ int Cartridge4A50::bank()
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// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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int Cartridge4A50::bankCount()
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{
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return 1;
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return 1; // TODO
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}
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// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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bool Cartridge4A50::patch(uInt16 address, uInt8 value)
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{
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return false;
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return false; // TODO
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}
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// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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uInt8* Cartridge4A50::getImage(int& size)
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{
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size = 0;
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size = 0; // TODO
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return 0;
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}
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@ -317,11 +317,83 @@ uInt8* Cartridge4A50::getImage(int& size)
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// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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bool Cartridge4A50::save(Serializer& out) const
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{
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string cart = name();
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try
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{
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out.putString(cart);
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// The 32K bytes of RAM
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out.putInt(32768);
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for(uInt32 i = 0; i < 32768; ++i)
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out.putByte((char)myRAM[i]);
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// Index pointers
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out.putInt(mySliceLow);
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out.putInt(mySliceMiddle);
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out.putInt(mySliceHigh);
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// Whether index pointers are for ROM or RAM
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out.putBool(myIsRomLow);
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out.putBool(myIsRomMiddle);
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out.putBool(myIsRomHigh);
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// Last address and data values
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out.putByte(myLastData);
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out.putInt(myLastAddress);
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}
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catch(const char* msg)
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{
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cerr << msg << endl;
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return false;
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}
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catch(...)
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{
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cerr << "Unknown error in save state for " << cart << endl;
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return false;
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}
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return true;
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}
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// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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bool Cartridge4A50::load(Deserializer& in)
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{
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string cart = name();
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try
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{
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if(in.getString() != cart)
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return false;
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uInt32 limit = (uInt32) in.getInt();
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for(uInt32 i = 0; i < limit; ++i)
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myRAM[i] = (uInt8) in.getByte();
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// Index pointers
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mySliceLow = (uInt16) in.getInt();
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mySliceMiddle = (uInt16) in.getInt();
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mySliceHigh = (uInt16) in.getInt();
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// Whether index pointers are for ROM or RAM
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myIsRomLow = in.getBool();
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myIsRomMiddle = in.getBool();
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myIsRomHigh = in.getBool();
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// Last address and data values
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myLastData = (uInt8) in.getByte();
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myLastAddress = (uInt16) in.getInt();
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}
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catch(const char* msg)
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{
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cerr << msg << endl;
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return false;
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}
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catch(...)
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{
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cerr << "Unknown error in load state for " << cart << endl;
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return false;
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}
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return true;
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}
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@ -13,7 +13,7 @@
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// See the file "license" for information on usage and redistribution of
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// this file, and for a DISCLAIMER OF ALL WARRANTIES.
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//
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// $Id: Cart4A50.hxx,v 1.11 2008-02-19 12:33:03 stephena Exp $
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// $Id: Cart4A50.hxx,v 1.12 2008-02-21 23:58:09 stephena Exp $
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//============================================================================
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#ifndef CARTRIDGE4A50_HXX
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@ -37,7 +37,7 @@ class System;
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bytes of ROM.
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@author Stephen Anthony & Eckhard Stolberg
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@version $Id: Cart4A50.hxx,v 1.11 2008-02-19 12:33:03 stephena Exp $
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@version $Id: Cart4A50.hxx,v 1.12 2008-02-21 23:58:09 stephena Exp $
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*/
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class Cartridge4A50 : public Cartridge
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{
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@ -148,11 +148,11 @@ class Cartridge4A50 : public Cartridge
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/**
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Check all possible hotspots
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*/
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void checkBankSwitch(uInt16 address);
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void checkBankSwitch(uInt16 address, uInt8 value);
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private:
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// The 128K ROM image of the cartridge
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uInt8 myImage[128*1024];
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uInt8 myImage[131072];
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// The 32K of RAM on the cartridge
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uInt8 myRAM[32768];
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