Merge branch 'master' of https://github.com/MoleskiCoder/EightBitNet

EightBit/Processor.cs

@@ -155,7 +155,9 @@ namespace EightBit
             }
         }
 
-        protected virtual void HandleRESET() => this.RaiseRESET();
+        protected virtual void HandleRESET()
+        {
+        }
 
         protected virtual void HandleINT() => this.RaiseINT();
 

Z80/Disassembler.cs

@@ -63,10 +63,10 @@ namespace Z80
                 + $"I={i:x2} R={(byte)r:x2} "
                 + $"IM={im} "
                 + $"IFF1={(cpu.IFF1 ? 1 : 0)} "
-                + $"{(cpu.RESET.Lowered() ? "R" : "-")}"
-                + $"{(cpu.INT.Lowered() ? "I" : "-")}"
                 + $"{(cpu.HALT.Lowered() ? "H" : "-")}"
-                + $"{(cpu.NMI.Lowered() ? "N" : "-")}";
+                + $"{(cpu.RESET.Lowered() ? "R" : "-")}"
+                + $"{(cpu.NMI.Lowered() ? "N" : "-")}"
+                + $"{(cpu.INT.Lowered() ? "I" : "-")}";
         }
 
         public string Disassemble(Z80 cpu)

Z80/Z80.UnitTests/ResetTests.cs

@@ -64,12 +64,12 @@ namespace Z80.UnitTests
         }
 
         [TestMethod]
-        public void Reset_Deasserts_Reset_Pin()
+        public void Reset_Ignores_Reset_Pin()
         {
             this.cpu.LowerRESET(); // asserts RESET — fires LoweredRESET event
             Assert.IsTrue(this.cpu.RESET.Lowered(), "RESET pin must be asserted before step");
             this.cpu.Step();
-            Assert.IsTrue(this.cpu.RESET.Raised(), "HandleRESET must deassert the RESET pin");
+            Assert.IsTrue(this.cpu.RESET.Lowered());
         }
 
         [TestMethod]

Z80/Z80.cs

@@ -17,14 +17,12 @@ namespace Z80
             this.UpdateRegisterBank();
             this.UpdateAFBank();
             this.RaisedPOWER += this.Z80_RaisedPOWER;
-            this.LoweredRESET += this.Z80_LoweredRESET;
             this.LoweredNMI += this.Z80_LoweredNMI;
             this.LoweredINT += this.Z80_LoweredINT;
         }
 
         private bool _interruptPending;
         private bool _nonMaskableInterruptPending;
-        private bool _resetPending;
 
         private readonly InputOutput _ports;
 
@@ -182,9 +180,8 @@ namespace Z80
             this._modifiedF = 0;
             this._displaced = this._prefixCB = this._prefixDD = this._prefixED = this._prefixFD = false;
 
-            if (this._resetPending)
+            if (this.RESET.Lowered())
             {
-                this._resetPending = false;
                 this.HandleRESET();
                 return;
             }
@@ -204,6 +201,8 @@ namespace Z80
                 }
             }
 
+            Debug.Assert(this.RESET.Raised());
+
             // ** From the Z80 CPU User Manual
             // When a software HALT instruction is executed, the CPU executes NOPs until an interrupt
             // is received(either a non-maskable or a maskable interrupt while the interrupt flip-flop is
@@ -252,8 +251,6 @@ namespace Z80
 
         private void Z80_LoweredNMI(object? sender, EventArgs e) => this._nonMaskableInterruptPending = true;
 
-        private void Z80_LoweredRESET(object? sender, EventArgs e) => this._resetPending = true;
-
         #region Z80 specific pins
 
         #region NMI pin
@@ -594,10 +591,10 @@ namespace Z80
         protected override void HandleRESET()
         {
             base.HandleRESET();
-            this.DisableInterrupts();
             this.IM = 0;
             this.IV = this.REFRESH = 0;
             this.SP.Joined = this.AF.Joined = (ushort)Mask.Sixteen;
+            this.Tick();
         }
 
         private byte ReadDataUnderInterrupt()