public override string Print()
{
return(address.ToString());
}
/// <summary>
/// Returns a human-readable description of the instruction and operand value located
/// at Address. The string has two parts, delimited by a |
/// mnemonic target address | complete description of instruction and result
/// </summary>
/// <param name="Address">Absolute address of 3-byte instruction</param>
/// <returns>String with description</returns>
public String GetInstructionDescription(int Address)
{
string Result = string.Empty;
string Details = string.Empty;
string Effect = string.Empty;
int Word;
Word = this.FetchWord(Address); // Fetch the Word at Address
int TargetAddress;
int OpCode;
bool INDEXED = false;
int XBit = 0;
XBit = (Word & 0x8000);
INDEXED = (XBit > 0);
TargetAddress = Word & 0x7FFF;
OpCode = Word & 0xFF0000;
OpCode = OpCode >> 16;
switch (OpCode)
{
case 0x18: // ADD
Result = "ADD";
Details = "Add Value in Target Address to Register A";
Effect = "A <- (A) + (TA)";
break;
case 0x40: // AND
Result = "AND";
Details = "Perform Bitwise AND on Value in Target Address and Register A, store result in A";
Effect = "A <- (A) && (TA)";
break;
case 0x28: // CMP (Compare and set Status Word SW)
Result = "CMP";
break;
case 0x24: // DIV
Result = "DIV";
Details = "Divide Register A by Value in Target Address ";
Effect = "A <- (A) / (TA)";
break;
case 0x3C: // J
Result = "J";
Details = "Perform Unconditional Jump to Target Address";
Effect = "PC <- (TA)";
break;
case 0x30: // JEQ
Result = "JEQ";
Details = "Perform Conditional Jump to Target Address when CC = 00";
Effect = "PC <- (TA) if CC = 00";
break;
case 0x34: // JGT
Result = "JGT";
Details = "Perform Conditional Jump to Target Address when CC = 10";
Effect = "PC <- (TA) if CC = 10";
break;
case 0x38: // JLT
Result = "JLT";
Details = "Perform Conditional Jump to Target Address when CC = 01";
Effect = "PC <- (TA) if CC = 01";
break;
case 0x48: // JSUB (Jump to subroutine starting at TA. Preserve PC by storing in L)
Result = "JSUB";
Details = "Jump to Subroutine at Target Address. Preserve PC By Storing in L";
Effect = "L <- PC; PC <- (TA)";
break;
case 0x00: // LDA
Result = "LDA";
Details = "Load Value in Target Address to Register A";
Effect = "A <- (TA)";
break;
case 0x50: // LDCH
Result = "LDCH";
Details = "Load Character from Device Specified in Target Address to Rightmost Byte in A";
Effect = "A[rightmost byte] <- Device(TA)";
break;
case 0x08: // LDL
Result = "LDL";
Details = "Load Value in Target Address to Register L";
Effect = "L <- (TA)";
break;
case 0x04: // LDX
Result = "LDX";
Details = "Load Value in Target Address to Register X";
Effect = "X <- (TA)";
break;
case 0x20: // MUL
Result = "MUL";
Details = "Multiple Value in Target Address by Register A Store in A";
Effect = "A <- (A) * (TA)";
break;
case 0x44: // OR
Result = "OR";
Details = "Perform Bitwise OR on Value in Target Address and Register A, store result in A";
Effect = "A <- (A) || (TA)";
break;
case 0x4C: // RSUB
Result = "RSUB";
Details = "Return from Subroutine. ";
Effect = "PC <- (L)";
break;
case 0x0C: // STA (Stores contents of A in Target Address)
Result = "STA";
Details = "Store Value in Register A to Target Address";
Effect = "(TA) <- A";
break;
case 0x54: // STCH
Result = "STCH";
break;
case 0x14: // STL
Result = "STL";
Details = "Store Value in Register L to Target Address";
Effect = "(TA) <- L";
break;
case 0x10: // STX (Stores contents of X in Target Address)
Result = "STX";
Details = "Store Value in Register X to Target Address";
Effect = "(TA) <- X";
break;
case 0x1C: // SUB
Result = "SUB";
Details = "Sub Value in Target Address to Register A";
Effect = "A <- (A) - (TA)";
break;
case 0xE0: // TD (Tests to see if a device is busy).
Result = "TD";
Details = "Test Device Number Specified in Target Address";
Effect = "Set SW";
break;
case 0x2C: // TIX
Result = "TIX";
Details = "Increment value in X Register. Compare to value in Target Address";
Effect = "X <- X + 1; COMP X to M set CC";
break;
case 0xDC: // WD (Write to Device)
Result = "WD";
Details = "Write rightmost byte in A to Device Number in Target Address";
Effect = " Device(TA) <- A[rightmost byte]";
break;
default:
Result = "";
break;
}
Result += " ";
if (INDEXED == true)
{
Result += "TA = TA + X ->" + TargetAddress.ToString(("X6")) + '+' + X.ToString(("X6")) + "->" + (TargetAddress + TargetAddress + X).ToString(("X6"));
TargetAddress += this.X; // Add contents of X register to address for indexed Mode
}
else
{
Result += "TA = " + TargetAddress.ToString("X6");
}
Result = Result + "|" + Details + "|" + Effect;
return(Result);
}
