X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=src%2Fgpu.cpp;h=e5855fea7eda560f68fcdc186f74b781febaf36d;hb=f91072f8bd3a65d56cfb94eb022577f3f42016c6;hp=e1fdd41e8751be298c26804e4a198a37de0c4f7d;hpb=ab4f660439ff855171f801e3fdfa3e9de69d991b;p=virtualjaguar

diff --git a/src/gpu.cpp b/src/gpu.cpp
index e1fdd41..e5855fe 100644
--- a/src/gpu.cpp
+++ b/src/gpu.cpp
@@ -323,8 +323,8 @@ static uint32 gpu_div_control;
 // a bit before writing a result. I.e., if the result of an operation leaves a zero in
 // the carry flag, you don't have to zero gpu_flag_c before you can write that zero!
 static uint8 gpu_flag_z, gpu_flag_n, gpu_flag_c;
-static uint32 gpu_reg_bank_0[32];
-static uint32 gpu_reg_bank_1[32];
+uint32 gpu_reg_bank_0[32];
+uint32 gpu_reg_bank_1[32];
 static uint32 * gpu_reg;
 static uint32 * gpu_alternate_reg;
 
@@ -501,7 +501,11 @@ uint16 GPUReadWord(uint32 offset, uint32 who/*=UNKNOWN*/)
 uint32 GPUReadLong(uint32 offset, uint32 who/*=UNKNOWN*/)
 {
 	if (offset >= 0xF02000 && offset <= 0xF020FF)
-		WriteLog("GPU: ReadLong--Attempt to read from GPU register file by %s!\n", whoName[who]);
+	{
+		WriteLog("GPU: ReadLong--Attempt to read from GPU register file (%X) by %s!\n", offset, whoName[who]);
+		uint32 reg = (offset & 0xFC) >> 2;
+		return (reg < 32 ? gpu_reg_bank_0[reg] : gpu_reg_bank_1[reg - 32]); 
+	}
 
 //	if ((offset >= GPU_WORK_RAM_BASE) && (offset < GPU_WORK_RAM_BASE + 0x1000))
 	if ((offset >= GPU_WORK_RAM_BASE) && (offset <= GPU_WORK_RAM_BASE + 0x0FFC))
@@ -647,12 +651,15 @@ void GPUWriteWord(uint32 offset, uint16 data, uint32 who/*=UNKNOWN*/)
 		{
 //WriteLog("[GPU W16:%08X,%04X]", offset, data);
 			uint32 old_data = GPUReadLong(offset & 0xFFFFFFC, who);
+
 			if (offset & 0x02)
 				old_data = (old_data & 0xFFFF0000) | (data & 0xFFFF);
 			else
 				old_data = (old_data & 0x0000FFFF) | ((data & 0xFFFF) << 16);
+
 			GPUWriteLong(offset & 0xFFFFFFC, old_data, who);
 		}
+
 		return;
 	}
 	else if ((offset == GPU_WORK_RAM_BASE + 0x0FFF) || (GPU_CONTROL_RAM_BASE + 0x1F))
@@ -700,7 +707,9 @@ void GPUWriteLong(uint32 offset, uint32 data, uint32 who/*=UNKNOWN*/)
 		case 0x00:
 		{
 			bool IMASKCleared = (gpu_flags & IMASK) && !(data & IMASK);
-			gpu_flags = data;
+			// NOTE: According to the JTRM, writing a 1 to IMASK has no effect; only the
+			//       IRQ logic can set it. So we mask it out here to prevent problems...
+			gpu_flags = data & (~IMASK);
 			gpu_flag_z = gpu_flags & ZERO_FLAG;
 			gpu_flag_c = (gpu_flags & CARRY_FLAG) >> 1;
 			gpu_flag_n = (gpu_flags & NEGA_FLAG) >> 2;
@@ -771,6 +780,7 @@ WriteLog("GPU: %s setting GPU PC to %08X %s\n", whoName[who], gpu_pc, (GPU_RUNNI
 			{
 				//WriteLog("asked to perform a single step (single step is %senabled)\n",(data&0x8)?"":"not ");
 			}
+
 			gpu_control = (gpu_control & 0xF7C0) | (data & (~0xF7C0));
 
 			// if gpu wasn't running but is now running, execute a few cycles