From d36c030269663b892091f209a578daecefb12c67 Mon Sep 17 00:00:00 2001
From: Ivan Izaguirre <ivan@tuenti.com>
Date: Sat, 26 Jan 2019 16:59:36 +0100
Subject: [PATCH] First Commit

---
 execute.go        |  0
 memory.go         |  0
 registers.go      | 41 +++++++++++++++++++++++++++++++++++++++++
 registers_test.go | 20 ++++++++++++++++++++
 4 files changed, 61 insertions(+)
 create mode 100644 execute.go
 create mode 100644 memory.go
 create mode 100644 registers.go
 create mode 100644 registers_test.go

diff --git a/execute.go b/execute.go
new file mode 100644
index 0000000..e69de29
diff --git a/memory.go b/memory.go
new file mode 100644
index 0000000..e69de29
diff --git a/registers.go b/registers.go
new file mode 100644
index 0000000..360f55f
--- /dev/null
+++ b/registers.go
@@ -0,0 +1,41 @@
+package main
+
+const (
+	regA = 0
+	regX = 1
+	regY = 2
+	// empty
+	regP  = 4
+	regS  = 5
+	regPC = 6 // 2 bytes
+)
+
+type registers struct {
+	data [8]uint8
+}
+
+func (r registers) getA() uint8 { return r.data[regA] }
+func (r registers) getX() uint8 { return r.data[regX] }
+func (r registers) getY() uint8 { return r.data[regY] }
+func (r registers) getP() uint8 { return r.data[regP] }
+func (r registers) getS() uint8 { return r.data[regS] }
+
+func (r registers) setRegister(i int, v uint8) registers {
+	r.data[i] = v
+	return r
+}
+func (r registers) setA(v uint8) registers { return r.setRegister(regA, v) }
+func (r registers) setX(v uint8) registers { return r.setRegister(regX, v) }
+func (r registers) setY(v uint8) registers { return r.setRegister(regY, v) }
+func (r registers) setP(v uint8) registers { return r.setRegister(regP, v) }
+func (r registers) setS(v uint8) registers { return r.setRegister(regS, v) }
+
+func (r registers) getPC() uint16 {
+	return uint16(r.data[regPC])*256 + uint16(r.data[regPC+1])
+}
+
+func (r registers) setPC(v uint16) registers {
+	r.data[regPC] = uint8(v >> 8)
+	r.data[regPC+1] = uint8(v)
+	return r
+}
diff --git a/registers_test.go b/registers_test.go
new file mode 100644
index 0000000..b9d873c
--- /dev/null
+++ b/registers_test.go
@@ -0,0 +1,20 @@
+package main
+
+import "testing"
+
+func TestRegA(t *testing.T){
+	var r registers
+	var data uint8
+	data = 200
+	if r.setA(data).getA() != data {
+		t.Error("Error storing and loading A")
+	}
+}
+func TestRegPC(t *testing.T){
+	var r registers
+	var data uint16
+	data = 0xc600
+	if r.setPC(data).getPC() != data {
+		t.Error("Error storing and loading PC")
+	}
+}
\ No newline at end of file