static void Main(string[] args)
{
Console.WriteLine("6502 Emulator\n");
CPU cpu = new CPU();
// Emulate the 6502 start up, which looks for a vector at $FFFC/$FFFD
// and starts execution from there. Need to start one code before as
// we musn't have zero at the load point - any value other than 0 good.
// This is not required if we don't mind blue screen of death situations
cpu.RAM.LoadMemnory(0xFFFB, new byte[] { 0xff, 0x00, 0x50 });
// Variables for testing - including JMP($) for subroutine
cpu.RAM.LoadMemnory(0x0302, new byte[] { 0xaa, 0xbb, 23, 0x50 });
// JSR and RET Subroutine Test
cpu.RAM.LoadMemnory(0x6040, new byte[] { 0xa2, 0x05, 0x8a, 0xaa, 0xc8, 0x98, 0xc8, 0xa8, 0x88, 0xe8, 0xca, 0x60 });
// Main code. Tests nearly all functions, then finally JMPs to Fibonacci code
cpu.RAM.LoadMemnory(0x5000, new byte[] { 0x6c, 0x04, 0x03, 0xa1, 0xed, 0xa1, 0x00, 0xa1, 0xed, 0xa9, 0x01, 0xbd, 0x02, 0x01, 0xb1, 0xff, 0xa2, 127,
0xe8, 0xa2, 0xff, 0xe8, 0xca, 0xd0, 0x01, 0xea, 0xa2, 0x04, 0xca, 0xd0, 0xfd, 0xca, 0x20, 0x40, 0x60, 0xEA, 0x38, 0x18,
0xf8, 0xd8, 0x78, 0x58, 0x8d, 0x00, 0x40, 0xa9, 0x0, 0xad, 0x00, 0x40, 0x8e, 0x00, 0x40, 0xad, 0x00, 0x40,
0x4c, 0x00, 0x70 });
// Fibonacci Sequence
cpu.RAM.LoadMemnory(0x7000, new byte[] { 0xa0, 0x07, 0xa9, 0x00, 0x8d, 0x00, 0x40, 0xa9, 0x01,
0xaa, 0x18, 0x6d, 0x00, 0x40, 0x8e, 0x00, 0x40, 0x88, 0xd0, 0xf5, 0xea });
// Add some breakpoints for fun.
BreakpointMgr mgr = new BreakpointMgr();
BreakPointSet bps = new BreakPointSet(5, "5th time at 0x700e");
mgr.AddBreakPointSet(bps);
bps.AddBreakPoint("PC", 0x700e);
BreakPointSet bps2 = new BreakPointSet(1, "A = 8 and Y=2 for the first time");
mgr.AddBreakPointSet(bps2);
bps2.AddBreakPoint("A", 0x08);
bps2.AddBreakPoint("Y", 0x02);
// You dont need to name the break point, and if you dont provide a count
// it will assume the first time the breakpoint is hit.
BreakPointSet bps3 = new BreakPointSet();
mgr.AddBreakPointSet(bps3);
bps3.AddBreakPoint("Opcode", 0x18);
BreakPointSet bps4 = new BreakPointSet(1, "Stack has exactly one entry on");
mgr.AddBreakPointSet(bps4);
bps4.AddBreakPoint("SP", 0xfd);
BreakPointSet bps5 = new BreakPointSet(1, "Carry flag set");
mgr.AddBreakPointSet(bps5);
bps5.AddBreakPoint("C", 0x1);
// Simulate a reset and start the execution
cpu.Reset(mgr);
}
/// <summary>
/// Tests all breakpoints within the breakpointset, and returns true if all pass AND
/// the hit count is correct, otherwise false
/// </summary>
/// <param name="cpu"></param>
/// <param name="c"></param>
/// <returns></returns>
public bool ShallIBreak(CPU cpu, Cycle c)
{
bool shallIBreak = true;
foreach (Breakpoint bp in breakpoints)
{
switch (bp.Element)
{
case "Opcode":
{
if (cpu.Opcode != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "PC":
{
if (c.StartPC != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "A":
{
if (cpu.A != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "X":
{
if (cpu.X != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "Y":
{
if (cpu.Y != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "SP":
{
if (cpu.SP != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "C":
{
if ((cpu.Flags & CPU.FlagCarry) != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "D":
{
if ((cpu.Flags & CPU.FlagDecimal) != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "V":
{
if ((cpu.Flags & CPU.FlagOverflow) != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "I":
{
if ((cpu.Flags & CPU.FlagInterruptDisable) != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "N":
{
if ((cpu.Flags & CPU.FlagNegative) != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
case "Z":
{
if ((cpu.Flags & CPU.FlagZero) != bp.ValueForBreak)
{
shallIBreak = false;
}
break;
}
}
}
if (shallIBreak)
{
Count--;
if (Count != 0)
{
shallIBreak = false;
}
}
return(shallIBreak);
}