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Implemented many more OpCodes - again, again!

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This commit is contained in:
Marc Parsons
2026-04-13 22:51:20 +01:00
parent 9496c26004
commit 08d718f41e
2 changed files with 67 additions and 7 deletions
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40
Core/Cpu/Z80.cs
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@@ -449,6 +449,14 @@ namespace Core.Cpu
case 0x16: // LD D, n
DE.High = FetchByte();
return 7;
case 0x18: // JR d
sbyte jumpDistance = (sbyte)FetchByte();
// PC has already been incremented by FetchByte(), so it is
// pointing exactly where it needs to be for the relative addition.
PC = (ushort)(PC + jumpDistance);
return 12;
case 0x19: // ADD HL, DE
Add16(DE.Word);
return 11;
@@ -646,6 +654,9 @@ namespace Core.Cpu
case 0xDE: // SBC A, n
Sbc(FetchByte());
return 7;
case 0xE9: // JP (HL)
PC = HL.Word;
return 4; // Takes 4 T-States
case 0xEB: // EX DE, HL
ushort tempEx = DE.Word;
DE.Word = HL.Word;
@@ -856,11 +867,38 @@ namespace Core.Cpu
_memory.Write(targetAddress, memValRes4);
return 23;
case 0xAE: // RES 5, (IY+d)
byte memValRes5 = _memory.Read(targetAddress);
// 0xDF is Binary 1101 1111
// ANDing perfectly preserves all other bits while forcing Bit 5 to 0
memValRes5 &= 0xDF;
_memory.Write(targetAddress, memValRes5);
return 23;
case 0xC6: // SET 0, (IY+d)
byte memValSet0 = _memory.Read(targetAddress);
// 0x01 is Binary 0000 0001
// ORing forces Bit 0 to 1 and perfectly preserves all other bits
memValSet0 |= 0x01;
_memory.Write(targetAddress, memValSet0);
return 23; // Takes 23 T-States
case 0xCE: // SET 1, (IY+d)
memVal = _memory.Read(targetAddress);
memVal |= 0x02; // 0x02 is Binary 0000 0010 (Bit 1)
_memory.Write(targetAddress, memVal);
return 23; // Takes 23 T-States
return 23;
case 0xE6: // SET 4, (IY+d)
byte memValSet4 = _memory.Read(targetAddress);
// 0x10 is Binary 0001 0000
// ORing perfectly preserves all other bits while forcing Bit 4 to 1
memValSet4 |= 0x10;
_memory.Write(targetAddress, memValSet4);
return 23;
default:
throw new NotImplementedException($"FD CB opcode {bitOpcode:X2} not implemented!");