make6502.c

十七种模拟器源代码 非常有用的作课程设计不可缺少的

	if (0x0d == dwOpcode)
		Absolute();
	else
	if (0x05 == dwOpcode)
		ZeroPage();
	else
	if (0x09 == dwOpcode)
		Immediate("dl");
	else
	if (0x1d == dwOpcode)
		AbsoluteX();
	else
	if (0x19 == dwOpcode)
		AbsoluteY();
	else
	if (0x01 == dwOpcode)
		IndirectX();
	else
	if (0x11 == dwOpcode)
		IndirectY();
	else
	if (0x15 == dwOpcode)
		ZeroPageX();
	else
		assert(0);

	// Address is now in DX to read

	if (0x09 != dwOpcode)
	{
		if ((0x05 == dwOpcode || 0x15 == dwOpcode) && (bZeroDirect))
			fprintf(fp, "		mov	dl, [ebp+edx]	; Get our zero page data\n");
		else
			ReadMemoryByte("dl", "dx");
	}

	// Let's do the OR with A, shall we?

	fprintf(fp, "		mov	dh, ah	; Get the flags\n");
	fprintf(fp, "		or	al, dl		; OR In our value\n");
	fprintf(fp, "		lahf			; Get the flag settings\n");
	fprintf(fp, "		and	ah, 0c0h	; Only sign and zero flag\n");
	fprintf(fp, "		and	dh, 03fh	; Clear sign & zero flags\n");
	fprintf(fp, "		or	ah, dh		; Merge the affected flags together\n");

	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// EOR Handler

void EorHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; Eor\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	if (0x4d == dwOpcode)
		Absolute();
	else
	if (0x45 == dwOpcode)
		ZeroPage();
	else
	if (0x49 == dwOpcode)
		Immediate("dl");
	else
	if (0x5d == dwOpcode)
		AbsoluteX();
	else
	if (0x59 == dwOpcode)
		AbsoluteY();
	else
	if (0x41 == dwOpcode)
		IndirectX();
	else
	if (0x51 == dwOpcode)
		IndirectY();
	else
	if (0x55 == dwOpcode)
		ZeroPageX();
	else
		assert(0);

	// Address is now in DX to read

	if (0x49 != dwOpcode)
	{
		if ((0x45 == dwOpcode || 0x55 == dwOpcode) && (bZeroDirect))
			fprintf(fp, "		mov	dl, [ebp+edx]	; Get our zero page data\n");
		else
			ReadMemoryByte("dl", "dx");
	}

	// Let's do the XOR with A, shall we?

	fprintf(fp, "		mov	dh, ah	; Get the flags\n");
	fprintf(fp, "		xor	al, dl		; XOR In our value\n");
	fprintf(fp, "		lahf			; Get the flag settings\n");
	fprintf(fp, "		and	ah, 0c0h	; Only sign and zero flag\n");
	fprintf(fp, "		and	dh, 03fh	; Clear sign & zero flags\n");
	fprintf(fp, "		or	ah, dh		; Merge the affected flags together\n");

	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// STA Handler

void StaHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; STA\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	if (0x9d == dwOpcode)
		AbsoluteX();
	else
	if (0x99 == dwOpcode)
		AbsoluteY();
	else
	if (0x8d == dwOpcode)
		Absolute();
	else
	if (0x85 == dwOpcode)
		ZeroPage();
	else
	if (0x81 == dwOpcode)
		IndirectX();
	else
	if (0x91 == dwOpcode)
		IndirectY();
	else	
	if (0x95 == dwOpcode)
		ZeroPageX();
	else
		assert(0);

	if ((0x85 == dwOpcode || 0x95 == dwOpcode) && bZeroDirect)
		fprintf(fp, "		mov	[ebp+edx], al	; Store A\n");
	else
		WriteMemoryByte("al", "dx");

	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// STX Handler

void StxHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; STX\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	if (0x8e == dwOpcode)
		Absolute();
	else
	if (0x86 == dwOpcode)
		ZeroPage();
	else
	if (0x96 == dwOpcode)
		ZeroPageY();
	else
		assert(0);

	if ((0x86 == dwOpcode || 0x96 == dwOpcode) && bZeroDirect)
		fprintf(fp, "		mov	[ebp+edx], bl	; Store X\n");
	else
		WriteMemoryByte("bl", "dx");

	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// STY Handler

void StyHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; STY\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	if (0x8c == dwOpcode)
		Absolute();
	else
	if (0x84 == dwOpcode)
		ZeroPage();
	else
	if (0x94 == dwOpcode)
		ZeroPageX();
	else
		assert(0);

	if ((0x86 == dwOpcode || 0x96 == dwOpcode) && bZeroDirect)
		fprintf(fp, "		mov	[ebp+edx], cl	; Store Y\n");
	else
		WriteMemoryByte("cl", "dx");

	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// LDA Handler

void LdaHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; LDA\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	if (0xa9 == dwOpcode)
		Immediate("al");
	else
	if (0xad == dwOpcode)
		Absolute();
	else
	if (0xa5 == dwOpcode)
		ZeroPage();
	else
	if (0xbd == dwOpcode)
		AbsoluteX();
	else
	if (0xb9 == dwOpcode)
		AbsoluteY();
	else
	if (0xa1 == dwOpcode)
		IndirectX();
	else
	if (0xb1 == dwOpcode)
		IndirectY();
	else
	if (0xb5 == dwOpcode)
		ZeroPageX();
	else
		assert(0);

	if (0xa9 != dwOpcode)
	{
		if (bZeroDirect && (0xb5 == dwOpcode || 0xa5 == dwOpcode))
			fprintf(fp, "		mov	al, [ebp+edx]	; Get our zero page byte\n");
		else
			ReadMemoryByte("al", "dx");
	}

	SetZeroSign("al");			// Set flags according to A

	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// TXS

void TxsHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; TXS\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	fprintf(fp, "		mov	[_%ss], bl	; X -> S\n", cpubasename);

	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// TSX

void TsxHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; TSX\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	fprintf(fp, "		mov	bl, [_%ss]	; S -> X\n", cpubasename);

	SetZeroSign("bl");			// Set flags according to X
	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// TAX

void TaxHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; TAX\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	fprintf(fp,	"		mov	bl, al	; X = A\n");

	SetZeroSign("bl");			// Set flags according to X
	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// TXA

void TxaHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; TXA\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	fprintf(fp,	"		mov	al, bl	; A = X\n");

	SetZeroSign("al");			// Set flags according to A
	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// TAY

void TayHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; TAY\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	fprintf(fp,	"		mov	cl, al	; Y = A\n");

	SetZeroSign("cl");			// Set flags according to Y
	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// TYA

void TyaHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; TYA\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	fprintf(fp,	"		mov	al, cl	; A = Y\n");

	SetZeroSign("al");			// Set flags according to A
	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// Branch handler

void BranchHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; Branch\n");
	fprintf(fp, ";\n");

	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	// Put test case here

	if (0xd0 == dwOpcode)	// BNE
	{
		fprintf(fp, "		test	ah, 40h	; Are we non-zero?\n");
		fprintf(fp, "		jz	short takeJump%.2x	; Do it!\n", dwOpcode);
	}
	else
	if (0x30 == dwOpcode)	// BMI
	{
		fprintf(fp, "		test	ah, 80h	; Are we minus?\n");
		fprintf(fp, "		jnz	short takeJump%.2x	; Do it!\n", dwOpcode);
	}
	else
	if (0xb0 == dwOpcode)	// BCS
	{
		fprintf(fp, "		test	ah, 1h	; Is carry set?\n");
		fprintf(fp, "		jnz	short takeJump%.2x	; Do it!\n", dwOpcode);
	}
	else
	if (0x10 == dwOpcode)	// BPL
	{
		fprintf(fp, "		test	ah, 80h	; Are we plus?\n");
		fprintf(fp, "		jz		short takeJump%.2x ; Do it!\n", dwOpcode);
	}
	else
	if (0x70 == dwOpcode)	// BVS
	{
		fprintf(fp, "		test	ah, 10h	; Overflow set?\n");
		fprintf(fp, "		jnz	short takeJump%.2x ; Do it!\n", dwOpcode);
	}
	else
	if (0x50 == dwOpcode)	// BVC
	{
		fprintf(fp, "		test	ah, 10h	; Overflow not set?\n");
		fprintf(fp, "		jz	short takeJump%.2x ; Do it!\n", dwOpcode);
	}
	else
	if (0xf0 == dwOpcode)	// BEQ
	{
		fprintf(fp, "		test	ah, 40h	; Non-zero set?\n");
		fprintf(fp, "		jnz	short takeJump%.2x ; Do it!\n", dwOpcode);
	}
	else
	if (0x90 == dwOpcode)	// BCC
	{
		fprintf(fp, "		test	ah, 1h	; Carry not set?\n");
		fprintf(fp, "		jz		short takeJump%.2x ; Do it!\n", dwOpcode);
	}
	else
		assert(0);

	fprintf(fp, "		inc	esi	; Skip past the offset\n");
	FetchAndExec(bTimingTable[dwOpcode] - 1);

	fprintf(fp, "takeJump%.2x:\n", dwOpcode);
	FetchInstructionByte();		// Go get our offset just in case

	fprintf(fp, "		movsx	dx, dl\n");

	if (bBankswitch)
	{
		PageToPC();
		fprintf(fp, "		add	si, dx\n");
		fprintf(fp, "		mov	[_%spc], si\n", cpubasename);
		PCToPage();
	}
	else
	{
		fprintf(fp, "		sub	esi, ebp\n");
		fprintf(fp, "		add	si, dx\n");
		fprintf(fp, "		add	esi, ebp\n");
	}

	++dwGlobalLabel;
	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// JMP

void JmpHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; JMP\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	FetchInstructionWord();

	if (0x6c == dwOpcode)
		ReadMemoryWord();

	if (bBankswitch)
	{
		fprintf(fp, "		xor	esi, esi\n");
		fprintf(fp, "		mov	si, dx\n");
		fprintf(fp, "		mov	[_%spc], si\n", cpubasename);
		PCToPage();
	}
	else
	{
		fprintf(fp, "		add	edx, ebp	; Add in our base\n");
		fprintf(fp, "		mov	esi, edx	; Put it here for execution\n");
	}

	++dwGlobalLabel;
	FetchAndExec(bTimingTable[dwOpcode]);
	ProcEnd(string);
}

// Brk

void BrkHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	fprintf(fp, "; BRK\n");
	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	if (bBankswitch)
		PageToPC();
	else
		fprintf(fp, "		sub	esi, ebp	 ; Get our real program counter\n");

	fprintf(fp, "		inc	si	; Move to the next position\n");
	fprintf(fp, "		or	[_altFlags], byte 14h	; Indicate a break happened\n");

	FlagsX86to6502();

	fprintf(fp, "		mov	dl, [_%ss]	; Get our stack pointer\n", cpubasename);
	fprintf(fp, "		add	dx, 0ffh		; Stack area is 100-1ffh\n");
	fprintf(fp, "		mov	[edx+ebp], si	; Store our PC\n");
	fprintf(fp, "		dec	dx		; Back up for flag storage\n");

	fprintf(fp, "		mov	[edx+ebp], ah	; Store our flags\n");
	fprintf(fp, "		dec	dx		; Back up for flag storage\n");