diff --git a/Circuit.cpp b/Circuit.cpp
index b6ef4e7..497bb09 100644
--- a/Circuit.cpp
+++ b/Circuit.cpp
@@ -8,10 +8,6 @@
 #include "Circuit.h"
 #include "trans.h"
 
-Circuit::Circuit(Segment* extendFrom) {
-    extend(extendFrom);
-}
-
 /*
  * Adds segment extendFrom, and all segments electrically connected to it.
  * This happens recursively, but we don't recurse past ground or voltage supply.
@@ -19,8 +15,11 @@ Circuit::Circuit(Segment* extendFrom) {
 void Circuit::extend(Segment* extendFrom) {
     auto ret = this->segs.insert(extendFrom);
     if (!ret.second) {
+        /* We've already processed this segment. */
         return;
     }
+
+    /* Don't recurse past ground or voltage supply. */
     if (extendFrom->vss || extendFrom->vcc) {
         return;
     }
diff --git a/Circuit.h b/Circuit.h
index edfb112..1657aa2 100644
--- a/Circuit.h
+++ b/Circuit.h
@@ -9,28 +9,43 @@
 #define	CIRCUIT_H
 
 #include <set>
+#include "trans.h"
 
-class Segment;
-
+/*
+ * Builds a circuit, given one segment in that circuit.
+ * Extends the given segment by traversing the ON
+ * transistors it is connected to, recursively, until
+ * hitting ground and voltage supply. Provides iterators
+ * for retrieving all the circuit's segments.
+ */
 class Circuit {
 public:
-    Circuit(Segment* extendFrom);
+
+    Circuit(Segment* extendFrom) {
+        extend(extendFrom);
+    }
 
     virtual ~Circuit() {
     }
 
     bool getValue();
-    std::set<Segment*>::iterator begin() { return this->segs.begin(); }
-    std::set<Segment*>::iterator end() { return this->segs.end(); }
+
+    setpSeg::iterator begin() {
+        return this->segs.begin();
+    }
+
+    setpSeg::iterator end() {
+        return this->segs.end();
+    }
 
 private:
-    Circuit(const Circuit&);
-    Circuit& operator=(const Circuit&);
+
+    Circuit(const Circuit&) = delete;
+    Circuit& operator=(const Circuit&) = delete;
 
     void extend(Segment* extendFrom);
 
-    std::set<Segment*> segs;
+    setpSeg segs;
 };
 
 #endif	/* CIRCUIT_H */
-
diff --git a/Cpu6502.cpp b/Cpu6502.cpp
index 9616172..1d3c097 100644
--- a/Cpu6502.cpp
+++ b/Cpu6502.cpp
@@ -29,7 +29,7 @@
 #endif
 
 #ifdef TRACESEG
-#define dumpSegs() dumpSegments()
+#define dumpSegs() this->trace.dumpSegments()
 #else
 #define dumpSegs()
 #endif
@@ -59,7 +59,7 @@ void Cpu6502::powerOn() {
     initPins();
 
     std::cout << "initial full calculation..." << std::endl;
-    recalc(segs.all());
+    StateCalculator::recalc(segs.all());
     dumpRegs();
     dumpSegs();
 }
@@ -68,14 +68,6 @@ void Cpu6502::setSeg(Segment* s, bool on) {
     s->set(on);
 }
 
-void Cpu6502::recalc(Segment* s) {
-    StateCalculator::recalc(s);
-}
-
-void Cpu6502::recalc(std::set<Segment*> s) {
-    StateCalculator::recalc(s);
-}
-
 void Cpu6502::initPins() {
     // set voltage supply and ground.
     setSeg(n->VCC, true);
@@ -108,7 +100,7 @@ void Cpu6502::initPins() {
 
 void Cpu6502::reset() {
     setSeg(n->RES, true);
-    recalc(n->RES);
+    StateCalculator::recalc(n->RES);
 }
 
 void Cpu6502::tick() {
@@ -138,7 +130,7 @@ void Cpu6502::step() {
 
 void Cpu6502::clock(bool phase) {
     setSeg(n->CLK0, phase);
-    recalc(n->CLK0);
+    StateCalculator::recalc(n->CLK0);
 }
 
 void Cpu6502::rw() {
@@ -146,9 +138,9 @@ void Cpu6502::rw() {
     if (n->CLK2OUT->on) {
         readBus();
 
-        std::set<Segment*> s;
+        setpSeg s;
         segs.addDataToRecalc(s);
-        recalc(s);
+        StateCalculator::recalc(s);
 
         writeBus();
     }
diff --git a/Cpu6502.h b/Cpu6502.h
index 05bf5c5..0d96611 100644
--- a/Cpu6502.h
+++ b/Cpu6502.h
@@ -42,8 +42,6 @@ private:
     void write(unsigned short addr, unsigned char data);
 
     static void setSeg(Segment* s, bool on);
-    void recalc(Segment* s);
-    void recalc(std::set<Segment*> s);
 
     TransNetwork& transNetwork;
     AddressBus& addressBus;
diff --git a/Makefile b/Makefile
index 24a8624..8ccfa5e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
-CXXFLAGS=-g -std=c++11 -Wall -O4
+CXXFLAGS=-g -std=c++11 -Wall -O0
 
-SRCS = v6502.cpp trans.cpp SegmentCache.cpp TransNetwork.cpp Trace.cpp Circuit.cpp StateCalculator.cpp Cpu6502.cpp
+SRCS = v6502.cpp SegmentCache.cpp TransNetwork.cpp Trace.cpp Circuit.cpp StateCalculator.cpp Cpu6502.cpp
 OBJS = $(SRCS:.cpp=.o)
 DEPS = $(SRCS:.cpp=.d)
 
diff --git a/SegmentCache.cpp b/SegmentCache.cpp
index 74935d4..0e58373 100644
--- a/SegmentCache.cpp
+++ b/SegmentCache.cpp
@@ -95,7 +95,7 @@ void SegmentCache::setDataSegs(const unsigned char data) {
     this->c->DB7->set(x & 1);
 }
 
-void SegmentCache::addDataToRecalc(std::set<Segment*>& s) {
+void SegmentCache::addDataToRecalc(setpSeg& s) {
     s.insert(this->c->DB0);
     s.insert(this->c->DB1);
     s.insert(this->c->DB2);
diff --git a/SegmentCache.h b/SegmentCache.h
index c004a40..5113117 100644
--- a/SegmentCache.h
+++ b/SegmentCache.h
@@ -27,8 +27,8 @@ public:
     Segment* getOrAdd(const std::string& id);
     Segment* get(const std::string& id) const;
 
-    std::set<Segment*> all() {
-        std::set<Segment*> s;
+    setpSeg all() const {
+        setpSeg s;
         for (auto i : this->cache) {
             s.insert(i.second.get());
         }
@@ -182,7 +182,10 @@ public:
     unsigned short rPC() const;
 
     void setDataSegs(const unsigned char data);
-    void addDataToRecalc(std::set<Segment*>& s);
+    void addDataToRecalc(setpSeg& s);
+
+    std::map<const std::string, std::shared_ptr<Segment > >::const_iterator begin() const { return this->cache.begin(); }
+    std::map<const std::string, std::shared_ptr<Segment > >::const_iterator end() const { return this->cache.end(); }
 
 private:
     std::map<const std::string, std::shared_ptr<Segment > > cache;
diff --git a/StateCalculator.cpp b/StateCalculator.cpp
index 33c7fd4..aca7068 100644
--- a/StateCalculator.cpp
+++ b/StateCalculator.cpp
@@ -10,16 +10,8 @@
 #include "trans.h"
 #include <set>
 
-//void StateCalculator::recalcAll() {
-//    std::set<int> riSeg;
-//    for (int iSeg = 0; iSeg < segs.size(); ++iSeg) {
-//        addRecalc(iSeg,riSeg);
-//    }
-//    recalc(riSeg);
-//}
-
 void StateCalculator::recalc(Segment* seg) {
-    std::set<Segment*> rSeg;
+    setpSeg rSeg;
     rSeg.insert(seg);
     recalc(rSeg);
 }
@@ -32,10 +24,10 @@ void StateCalculator::recalc(Segment* seg) {
  */
 #define SANE (100)
 
-void StateCalculator::recalc(const std::set<Segment*>& segs) {
+void StateCalculator::recalc(const setpSeg& segs) {
     int sanity(0);
 
-    std::set<Segment*> changed(segs);
+    setpSeg changed(segs);
     while (!changed.empty()) {
         if (++sanity >= SANE) {
             throw "ERROR: reached maximum iteration limit while recalculating CPU state";
@@ -45,7 +37,7 @@ void StateCalculator::recalc(const std::set<Segment*>& segs) {
         for (auto s : changed) {
             c.recalcNode(s);
         }
-        changed = c.getChanged();
+        changed = c.segs;
     }
 }
 
diff --git a/StateCalculator.h b/StateCalculator.h
index 2eebcd7..3337ecf 100644
--- a/StateCalculator.h
+++ b/StateCalculator.h
@@ -9,17 +9,15 @@
 #define	STATECALCULATOR_H
 
 #include <set>
-
-class Segment;
-class Trans;
+#include "trans.h"
 
 class StateCalculator {
 public:
-    static void recalc(const std::set<Segment*>& rSeg);
-    static void recalc(Segment* seg);
+
+    static void recalc(const setpSeg& rSeg);
+    static void recalc(Segment* seg); // convenience method
 
 private:
-    std::set<Segment*> segs;
 
     StateCalculator() {
     }
@@ -27,17 +25,15 @@ private:
     virtual ~StateCalculator() {
     }
 
-    StateCalculator(const StateCalculator&);
-    StateCalculator& operator=(const StateCalculator&);
+    StateCalculator(const StateCalculator&) = delete;
+    StateCalculator& operator=(const StateCalculator&) = delete;
 
     void recalcNode(Segment* seg);
     void setSeg(Segment* s, const bool on);
     void setTrans(Trans* t, const bool on);
     void addRecalc(Segment* seg);
 
-    std::set<Segment*> getChanged() {
-        return this->segs;
-    }
+    setpSeg segs;
 };
 
 #endif	/* STATECALCULATOR_H */
diff --git a/Trace.cpp b/Trace.cpp
index 5da30ff..7864436 100644
--- a/Trace.cpp
+++ b/Trace.cpp
@@ -9,6 +9,7 @@
 #include "SegmentCache.h"
 #include <iostream>
 #include <iomanip>
+#include <cassert>
 
 static void pHex(const unsigned long x, const int width) {
     std::cout << std::setw(width) << std::setfill('0') << std::hex << x << std::dec;
@@ -23,22 +24,18 @@ static void pHexw(const unsigned short x) {
 }
 
 void Trace::dumpSegments() const {
-//    for (int i = 0; i < segs.size(); ++i) {
-//        seg& s = segs[i];
-//        if (s.pullup) {
-//            std::cout << "U";
-//        } else if (s.pulldown) {
-//            std::cout << "D";
-//        } else {
-//            std::cout << "f";
-//        }
-//        if (s->on) {
-//            std::cout << "+";
-//        } else {
-//            std::cout << "-";
-//        }
-//    }
-//    std::cout << std::endl;
+    for (auto sp : this->s) {
+        Segment* seg = sp.second.get();
+        assert(!(seg->pullup && seg->pulldown));
+        if (seg->pullup) {
+            std::cout << (seg->on ? "U" : "u");
+        } else if (seg->pulldown) {
+            std::cout << (seg->on ? "D" : "d");
+        } else {
+            std::cout << (seg->on ? "F" : "f");
+        }
+    }
+    std::cout << std::endl;
 }
 
 void Trace::dumpRegisters() const {
diff --git a/TransNetwork.cpp b/TransNetwork.cpp
index b9f3db1..f87884a 100644
--- a/TransNetwork.cpp
+++ b/TransNetwork.cpp
@@ -7,6 +7,8 @@
 
 #include "TransNetwork.h"
 #include "trans.h"
+#include <set>
+#include <string>
 #include <memory>
 #include <iostream>
 
diff --git a/TransNetwork.h b/TransNetwork.h
index c41a0a3..30d7826 100644
--- a/TransNetwork.h
+++ b/TransNetwork.h
@@ -8,22 +8,26 @@
 #ifndef TRANSNETWORK_H
 #define	TRANSNETWORK_H
 
-#include "trans.h"
+class Trans;
 #include "SegmentCache.h"
+#include <set>
+#include <memory>
 #include <istream>
 
 class TransNetwork {
 public:
-    SegmentCache segs;
-    std::set<std::shared_ptr<Trans>> transes;
 
-public:
+    SegmentCache segs;
+
     TransNetwork(std::istream& readFromHere);
     virtual ~TransNetwork();
 
 private:
+
     TransNetwork(const TransNetwork&) = delete;
     TransNetwork& operator=(const TransNetwork&) = delete;
+
+    std::set<std::shared_ptr<Trans >> transes;
 };
 
 #endif	/* TRANSNETWORK_H */
diff --git a/ptr_less.h b/ptr_less.h
new file mode 100644
index 0000000..98dd6d4
--- /dev/null
+++ b/ptr_less.h
@@ -0,0 +1,20 @@
+/* 
+ * File:   ptr_less.h
+ * Author: Christopher
+ *
+ * Created on December 14, 2013, 5:44 PM
+ */
+
+#ifndef PTR_LESS_H
+#define	PTR_LESS_H
+
+template<typename T>
+struct ptr_less {
+
+    bool operator()(T* pa, T* pb) {
+        return *pa < *pb;
+    }
+
+};
+
+#endif	/* PTR_LESS_H */
diff --git a/trans.cpp b/trans.cpp
deleted file mode 100644
index 56996cb..0000000
--- a/trans.cpp
+++ /dev/null
@@ -1,40 +0,0 @@
-/* 
- * File:   Trans.cpp
- * Author: cmosher
- * 
- * Created on December 11, 2013, 10:44 AM
- */
-
-#include "trans.h"
-
-unsigned char Segment::asByte(Segment* b7, Segment* b6, Segment* b5, Segment* b4, Segment* b3, Segment* b2, Segment* b1, Segment* b0) {
-    return
-        b7->on << 0x7 |
-        b6->on << 0x6 |
-        b5->on << 0x5 |
-        b4->on << 0x4 |
-        b3->on << 0x3 |
-        b2->on << 0x2 |
-        b1->on << 0x1 |
-        b0->on;
-}
-
-unsigned short Segment::asWord(Segment* bf, Segment* be, Segment* bd, Segment* bc, Segment* bb, Segment* ba, Segment* b9, Segment* b8, Segment* b7, Segment* b6, Segment* b5, Segment* b4, Segment* b3, Segment* b2, Segment* b1, Segment* b0) {
-    return
-        bf->on << 0xf |
-        be->on << 0xe |
-        bd->on << 0xd |
-        bc->on << 0xc |
-        bb->on << 0xb |
-        ba->on << 0xa |
-        b9->on << 0x9 |
-        b8->on << 0x8 |
-        b7->on << 0x7 |
-        b6->on << 0x6 |
-        b5->on << 0x5 |
-        b4->on << 0x4 |
-        b3->on << 0x3 |
-        b2->on << 0x2 |
-        b1->on << 0x1 |
-        b0->on;
-}
diff --git a/trans.h b/trans.h
index c7238a0..893a79a 100644
--- a/trans.h
+++ b/trans.h
@@ -10,6 +10,7 @@
 
 #include <string>
 #include <set>
+#include "ptr_less.h"
 
 class Trans;
 
@@ -34,10 +35,19 @@ public:
         this->pulldown = !up;
     }
 
-    static unsigned char asByte(Segment* b7, Segment* b6, Segment* b5, Segment* b4, Segment* b3, Segment* b2, Segment* b1, Segment* b0);
-    static unsigned short asWord(Segment* b15, Segment* b14, Segment* b13, Segment* b12, Segment* b11, Segment* b10, Segment* b9, Segment* b8, Segment* b7, Segment* b6, Segment* b5, Segment* b4, Segment* b3, Segment* b2, Segment* b1, Segment* b0);
+    static unsigned char asByte(Segment* b7, Segment* b6, Segment* b5, Segment* b4, Segment* b3, Segment* b2, Segment* b1, Segment* b0) {
+        return b7->on << 0x7 | b6->on << 0x6 | b5->on << 0x5 | b4->on << 0x4 | b3->on << 0x3 | b2->on << 0x2 | b1->on << 0x1 | b0->on;
+    }
+
+    static unsigned short asWord(Segment* bf, Segment* be, Segment* bd, Segment* bc, Segment* bb, Segment* ba, Segment* b9, Segment* b8, Segment* b7, Segment* b6, Segment* b5, Segment* b4, Segment* b3, Segment* b2, Segment* b1, Segment* b0) {
+        return bf->on << 0xf | be->on << 0xe | bd->on << 0xd | bc->on << 0xc | bb->on << 0xb | ba->on << 0xa | b9->on << 0x9 | b8->on << 0x8 | b7->on << 0x7 | b6->on << 0x6 | b5->on << 0x5 | b4->on << 0x4 | b3->on << 0x3 | b2->on << 0x2 | b1->on << 0x1 | b0->on;
+    }
+
+    bool operator<(const Segment& that) { return this->id < that.id; }
 };
 
+typedef std::set<Segment*,ptr_less<Segment>> setpSeg;
+
 class Trans {
 public:
     Segment* c1;
diff --git a/v6502.cpp b/v6502.cpp
index 801b475..5cab3ed 100644
--- a/v6502.cpp
+++ b/v6502.cpp
@@ -5,32 +5,9 @@
 #include <cstdlib>
 #include <iostream>
 #include <fstream>
+#include <set>
 
 
-
-//memory[0xFF] = 0x68;  // PLA
-
-//memory[0xFF] = 0xFF;
-//memory[0xFFFF] = 0xFE;
-//memory[0xFEFE] = 0xFD;
-//memory[0xFDFD] = 0xFC;
-//memory[0xFCFC] = 0xFB;
-//memory[0xFBFB] = 0xFA;
-//memory[0xFAFA] = 0xF9;
-
-//void pZP() {
-//    int a = 0;
-//    for (int i = 0; i < 16; ++i) {
-//        pHexw(a);
-//        std::cout << ": ";
-//        for (int j = 0; j < 16; ++j) {
-//            pHex(memory[a++]);
-//            std::cout << " ";
-//        }
-//        std::cout << std::endl;
-//    }
-//}
-
 int main(int argc, char *argv[]) {
     AddressBus mem;
 
@@ -58,9 +35,9 @@ int main(int argc, char *argv[]) {
     }
     TransNetwork tn(if_trans);
     Trace trace(tn.segs);
-    Cpu6502 cpu(tn,mem,trace);
+    Cpu6502 cpu(tn, mem, trace);
+
 
-