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

void Immediate(UINT8 *pszRegister)
{
	fprintf(fp, "		mov	%s, [esi]	; Get our next byte\n", pszRegister);
	fprintf(fp, "		inc	esi		; Increment to our next byte\n");
}

// LDX Handler

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

	if (0xa2 == dwOpcode)
		Immediate("bl");
	else
	if (0xae == dwOpcode)
		Absolute();
	else
	if (0xa6 == dwOpcode)
		ZeroPage();
	else
	if (0xbe == dwOpcode)
		AbsoluteY();
	else
	if (0xb6 == dwOpcode)
		ZeroPageY();
	else
		assert(0);

	if (0xa2 != dwOpcode)
	{
		if ((0xa6 != dwOpcode && 0xb6 != dwOpcode) || (FALSE == bZeroDirect))
			ReadMemoryByte("bl", "dx");
		else
			fprintf(fp, "		mov	bl, [ebp + edx]	; Zero page!\n");
	}

	SetZeroSign("bl");

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

// LDY Handler

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

	if (0xa0 == dwOpcode)
		Immediate("cl");
	else
	if (0xac == dwOpcode)
		Absolute();
	else
	if (0xa4 == dwOpcode)
		ZeroPage();
	else
	if (0xbc == dwOpcode)
		AbsoluteX();
	else
	if (0xb4 == dwOpcode)
		ZeroPageX();
	else
		assert(0);

	if (0xa0 != dwOpcode)
	{
		if ((0xa4 != dwOpcode && 0xb4 != dwOpcode) || (FALSE == bZeroDirect))
			ReadMemoryByte("cl", "dx");
		else
			fprintf(fp, "		mov	cl, [ebp + edx]	; Zero page!\n");
	}

	SetZeroSign("cl");

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

// DEC Handler

void DecxyHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	if (0x88 == dwOpcode)
		fprintf(fp, "; DEY\n");
	else
		fprintf(fp, "; DEX\n");

	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	if (0x88 == dwOpcode)
		DecSetZeroSign("cl");		// Decrement & do Y
	else
	if (0xca == dwOpcode)
		DecSetZeroSign("bl");		// Decrement & do X
	else
		assert(0);

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

// DeaIna Handler

void DeaInaHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	if (0x3a == dwOpcode)
		fprintf(fp, "; DEA\n");
	else
		fprintf(fp, "; INA\n");

	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	if (0x3a == dwOpcode)
		DecSetZeroSign("al");		// Decrement
	else
	if (0x1a == dwOpcode)
		DecSetZeroSign("al");		// Decrement
	else
		assert(0);

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

// INC Handler

void IncxyHandler(UINT16 dwOpcode)
{
	fprintf(fp, ";\n");
	if (0xc8 == dwOpcode)
		fprintf(fp, "; INY\n");
	else
		fprintf(fp, "; INX\n");

	fprintf(fp, ";\n");
	sprintf(string, "RegInst%.2x", dwOpcode);
	ProcBegin(string, dwOpcode);

	if (0xc8 == dwOpcode)
		IncSetZeroSign("cl");		// Increment & do Y
	else
	if (0xe8 == dwOpcode)
		IncSetZeroSign("bl");		// Increment & do X
	else
		assert(0);

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

// INC Handler

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

	if (0xee == dwOpcode || 0xfe == dwOpcode)
	{
		if (0xee == dwOpcode)
			Absolute();
		else
			AbsoluteX();
		fprintf(fp, "		push	edx	; Save this for later\n");
		ReadMemoryByte("dl", "dx");
		fprintf(fp, "		mov	bh, dl	; Save the data we just got\n");
	}
	else
	if (0xe6 == dwOpcode || 0xf6 == dwOpcode)
	{
		if (0xe6 == dwOpcode)
			ZeroPage();
		else
			ZeroPageX();

		if (FALSE == bZeroDirect)
		{
			fprintf(fp, "		push	edx	; Save this for later\n");
			ReadMemoryByte("dl", "dx");
			fprintf(fp, "		mov	bh, dl	; Save the data we just got\n");
		}		
	}
	else
		assert(0);

	// Handle the increment

	fprintf(fp, "		mov	ch, ah	; Save flags\n");
	fprintf(fp, "		and	ch, 03fh	; No sign or zero flags\n");

	if (((0xe6 == dwOpcode) || (0xf6 == dwOpcode)) && (bZeroDirect))
		fprintf(fp, "		inc	byte [edx+ebp]	; Increment our zero page stuff\n");
	else
		fprintf(fp, "		inc	bh		; Increment!\n");

	fprintf(fp, "		lahf\n");
	fprintf(fp, "		and	ah, 0c0h	; Only sign &  zero flags\n");
	fprintf(fp, "		or	ah, ch	; Merge the two flags together\n");

	if ( (0xee == dwOpcode || 0xfe == dwOpcode) ||
		  (((0xe6 == dwOpcode) || (0xf6 == dwOpcode)) && (FALSE == bZeroDirect)) )
	{
		fprintf(fp, "		pop	edx	; Restore our address\n");
		WriteMemoryByte("bh", "dx");
	}

	fprintf(fp, "		xor	bh, bh	; Zero this so we don't totally screw things up\n");
	fprintf(fp, "		xor	ch, ch	; Zero this as well\n");

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

// DEC Handler

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

	if (0xce == dwOpcode || 0xde == dwOpcode)
	{
		if (0xce == dwOpcode)
			Absolute();
		else
			AbsoluteX();

		fprintf(fp, "		push	edx	; Save this for later\n");
		ReadMemoryByte("dl", "dx");
		fprintf(fp, "		mov	bh, dl	; Save the data we just got\n");
	}
	else
	if (0xc6 == dwOpcode || 0xd6 == dwOpcode)
	{
		if (0xc6 == dwOpcode)
			ZeroPage();
		else
			ZeroPageX();

		if (FALSE == bZeroDirect)
		{
			fprintf(fp, "		push	edx	; Save this for later\n");
			ReadMemoryByte("dl", "dx");
			fprintf(fp, "		mov	bh, dl	; Save the data we just got\n");
		}		
	}
	else
		assert(0);

	// Handle the increment

	fprintf(fp, "		mov	ch, ah	; Save flags\n");
	fprintf(fp, "		and	ch, 03fh	; No sign or zero flags\n");

	if (((0xc6 == dwOpcode) || (0xd6 == dwOpcode)) && (bZeroDirect))
		fprintf(fp, "		dec	byte [edx+ebp]	; Increment our zero page stuff\n");
	else
		fprintf(fp, "		dec	bh		; Decrement!\n");

	fprintf(fp, "		lahf\n");
	fprintf(fp, "		and	ah, 0c0h	; Only sign &  zero flags\n");
	fprintf(fp, "		or	ah, ch	; Merge the two flags together\n");

	if ( (0xce == dwOpcode || 0xde == dwOpcode) ||
		  (((0xc6 == dwOpcode) || (0xd6 == dwOpcode)) && (FALSE == bZeroDirect)) )
	{
		fprintf(fp, "		pop	edx	; Restore our address\n");
		WriteMemoryByte("bh", "dx");
	}

	fprintf(fp, "		xor	bh, bh	; Zero this so we don't totally screw things up\n");
	fprintf(fp, "		xor	ch, ch	; Zero this as well\n");

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

// AND Handler

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

	if (0x2d == dwOpcode)
		Absolute();
	else
	if (0x25 == dwOpcode)
		ZeroPage();
	else
	if (0x29 == dwOpcode)
		Immediate("dl");
	else
	if (0x3d == dwOpcode)
		AbsoluteX();
	else
	if (0x39 == dwOpcode)
		AbsoluteY();
	else
	if (0x21 == dwOpcode)
		IndirectX();
	else
	if (0x31 == dwOpcode)
		IndirectY();
	else
	if (0x35 == dwOpcode)
		ZeroPageX();
	else
		assert(0);

	if ((bZeroDirect) && ((0x25 == dwOpcode) || (0x35 == dwOpcode)))
		fprintf(fp, "		and	al, [ebp+edx]	; And it!\n");
	else
	{
		if (0x29 != dwOpcode)
			ReadMemoryByte("dl", "dx");
		fprintf(fp, "		and	al, dl	; And it\n");
	}

	fprintf(fp, "		mov	bh, ah	; Save flags for later\n");
	fprintf(fp, "		lahf			; Get the flags\n");
	fprintf(fp, "		and	ah, 0c0h	; Only sign and zero flag\n");
	fprintf(fp, "		and	bh, 03fh	; Kill sign and zero flag\n");
	fprintf(fp, "		or	ah, bh	; Get our original (other) flags back\n");
	fprintf(fp, "		xor	bh, bh	; Kill it so we don't screw X up for later\n");

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

// ASL Handler

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

	if (0x0a == dwOpcode)
	{
		fprintf(fp, "		sahf		; Restore flags\n");
		fprintf(fp, "		mov	dl, ah	; Store our original flags\n");
		fprintf(fp, "		shl	al, 1	; Shift left by 1\n");
		fprintf(fp, "		lahf	; Load the flags back in\n");
		fprintf(fp, "		and	dl, 03eh	; No carry, zero, or sign\n");
		fprintf(fp, "		and	ah, 0c1h	; Only carry, zero and sign\n");
		fprintf(fp, "		or	ah, dl		; Or it into our flags\n");
	}
	else
	if (0x0e == dwOpcode)	// Absolute
		Absolute();
	else
	if (0x06 == dwOpcode)	// Zero page
		ZeroPage();
	else
	if (0x1e == dwOpcode)	// Absolute X
		AbsoluteX();
	else
	if (0x16 == dwOpcode)	// Zero page X
		ZeroPageX();
	else
		assert(0);

	// We have the address. Now fetch the info!

	if (0x0a != dwOpcode)
	{
		// Read the data

		if (((0x16 == dwOpcode) || (0x06 == dwOpcode)) && bZeroDirect)
			fprintf(fp, "		mov	bh, [ebp+edx]	; Get our zero page stuff\n");
		else
		{
			fprintf(fp, "		push	edx	; Save our address\n");
			ReadMemoryByte("bh", "dx");
			fprintf(fp, "		pop	edx	; Restore our address\n");
		}

		// Process the data

		fprintf(fp, "		sahf		; Restore flags\n");
		fprintf(fp, "		mov	ch, ah	; Store our original flags\n");
		fprintf(fp, "		shl	bh, 1	; Shift left by 1\n");
		fprintf(fp, "		lahf	; Load the flags back in\n");
		fprintf(fp, "		and	ch, 03eh	; No carry, zero, or sign\n");
		fprintf(fp, "		and	ah, 0c1h	; Only carry, zero and sign\n");
		fprintf(fp, "		or	ah, ch		; Or it into our flags\n");
		fprintf(fp, "		xor	ch, ch	; Clear it!\n");

		// Write the data back

		if (((0x16 == dwOpcode) || (0x06 == dwOpcode)) && bZeroDirect)
			fprintf(fp, "		mov	[ebp+edx], bh	; Set our zero page byte\n");
		else
			WriteMemoryByte("bh", "dx");
		fprintf(fp, "		xor	bh, bh	; Prevent us from being hosed later\n");
	}

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

// LSR Handler

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

	if (0x4a == dwOpcode)
	{
		fprintf(fp, "		sahf		; Restore flags\n");
		fprintf(fp, "		mov	dl, ah	; Store our original flags\n");
		fprintf(fp, "		shr	al, 1	; Shift right by 1\n");
		fprintf(fp, "		lahf	; Load the flags back in\n");
		fprintf(fp, "		and	dl, 03eh	; No carry, zero, or sign\n");
		fprintf(fp, "		and	ah, 0c1h	; Only carry, zero and sign\n");
		fprintf(fp, "		or	ah, dl		; Or it into our flags\n");
	}
	else
	if (0x4e == dwOpcode)	// Absolute
		Absolute();
	else
	if (0x46 == dwOpcode)	// Zero page
		ZeroPage();
	else
	if (0x5e == dwOpcode)	// Absolute X
		AbsoluteX();
	else
	if (0x56 == dwOpcode)	// Zero page X
		ZeroPageX();
	else
		assert(0);

	// We have the address. Now fetch the info!

	if (0x4a != dwOpcode)
	{
		// Read the data

		fprintf(fp, "		push	edx		; Save our address away\n");

		if (((0x56 == dwOpcode) || (0x46 == dwOpcode)) && bZeroDirect)
			fprintf(fp, "		mov	bh, [ebp+edx]	; Get our zero page stuff\n");
		else
			ReadMemoryByte("bh", "dx");

		// Process the data

		fprintf(fp, "		sahf		; Restore flags\n");
		fprintf(fp, "		mov	ch, ah	; Store our original flags\n");
		fprintf(fp, "		shr	bh, 1	; Shift right by 1\n");
		fprintf(fp, "		lahf	; Load the flags back in\n");
		fprintf(fp, "		and	ch, 03eh	; No carry, zero, or sign\n");
		fprintf(fp, "		and	ah, 0c1h	; Only carry, zero and sign\n");
		fprintf(fp, "		or	ah, ch		; Or it into our flags\n");
		fprintf(fp, "		xor	ch, ch	; Clear it!\n");

		// Write the data back

		fprintf(fp, "		pop	edx	; Restore our address\n");
		if (((0x56 == dwOpcode) || (0x46 == dwOpcode)) && bZeroDirect)
			fprintf(fp, "		mov	[ebp+edx], bh	; Set our zero page byte\n");
		else
			WriteMemoryByte("bh", "dx");
		fprintf(fp, "		xor	bh, bh	; Zero the upper part so we don't host X!\n");
	}

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

// ORA Handler

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