diff --git a/src/Makefile b/src/Makefile
index 3cd14c7..156cfd6 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,12 +1,16 @@
-OBJS = main.o omf.o handle.o map.o
+OBJS = main.o omf.o handle.o map.o disasm.o api.o
 CXX = clang++
-CXXFLAGS = -g -Wall -std=c++11
-LDFLAGS = -largp
+CXXFLAGS = -Wall -std=c++11
+
+UNAME := $(shell uname)
+ifeq ($(UNAME), Darwin)
+	LDFLAGS = -largp
+endif
 
 all: regs
 
 regs: $(OBJS)
-	$(CXX) $(CXXFLAGS) $(LIBS) -o $@ $^
+	$(CXX) $(CXXFLAGS) $(LIBS) -o $@ $(LDFLAGS) $^
 
 %.o: %.cc
 	$(CXX) -c $(CXXFLAGS) -o $@ $<
diff --git a/src/api.cc b/src/api.cc
new file mode 100644
index 0000000..2ce8179
--- /dev/null
+++ b/src/api.cc
@@ -0,0 +1,201 @@
+/** @copyright 2020 Sean Kasun */
+
+#include <iostream>
+#include "api.h"
+
+Fingerprints::Fingerprints() {
+  root = std::make_shared<Fingerprint>();
+}
+
+void Fingerprints::add(const std::vector<uint8_t> &keys, std::string name,
+                       uint8_t numDB) {
+  auto node = root;
+  for (auto key : keys) {
+    if (node->map.find(key) == node->map.end()) {
+      node->map.insert(std::pair<uint8_t, std::shared_ptr<Fingerprint>>
+                       (key, std::make_shared<Fingerprint>()));
+    }
+    node = node->map[key];
+  }
+  node->name = name;
+  node->numDB = numDB;
+}
+
+API::API(unsigned char *dat, unsigned int len) {
+  auto h = TheHandle::createFromArray(std::vector<uint8_t>(dat, dat + len));
+  auto numSymbols = h->r32();
+  for (uint32_t i = 0; i < numSymbols; i++) {
+    auto id = h->r32();
+    auto kind = h->r8();
+    auto name = h->rs();
+    ids.insert(std::pair<uint32_t, std::string>(id, name));
+    std::shared_ptr<symbol::Symbol> s = nullptr;
+    switch (kind) {
+      case symbol::isIntrinsic:
+        s = std::make_shared<symbol::Intrinsic>();
+        s->kind = symbol::isIntrinsic;
+        break;
+      case symbol::isEnum:
+        s = std::make_shared<symbol::Enum>();
+        s->kind = symbol::isEnum;
+        break;
+      case symbol::isAlias:
+        s = std::make_shared<symbol::Ref>();
+        s->kind = symbol::isAlias;
+        break;
+      case symbol::isStruct:
+        s = std::make_shared<symbol::Struct>();
+        s->kind = symbol::isStruct;
+        break;
+      case symbol::isUnion:
+        s = std::make_shared<symbol::Struct>();
+        s->kind = symbol::isUnion;
+        break;
+      case symbol::isRef:
+        std::cerr << "isRef on root!" << std::endl;
+        break;
+      case symbol::isFunction:
+        s = std::make_shared<symbol::Function>();
+        s->kind = symbol::isFunction;
+        break;
+      default:
+        std::cerr << "Unknown type" << std::endl;
+        break;
+    }
+    s->name = name;
+    symbols.insert(std::pair<std::string, symbol::Symbol>(name, s));
+  }
+
+  for (uint32_t i = 0; i < numSymbols; i++) {
+    auto id = h->r32();
+    auto s = symbols[ids[id]];
+    s->size = h->r32();
+    switch (s->kind) {
+      case symbol::isIntrinsic:
+        setIntrinsic(h, s);
+        break;
+      case symbol::isEnum:
+        setEnum(h, s);
+        break;
+      case symbol::isAlias:
+        setRef(h, s);
+        break;
+      case symbol::isStruct:
+        setStruct(h, s);
+        break;
+      case symbol::isUnion:
+        setStruct(h, s);
+        break;
+      case symbol::isRef:
+        std::cerr << "base level ref" << std::endl;
+        break;
+      case symbol::isFunction:
+        setFunction(h, s);
+        break;
+    }
+  }
+}
+
+std::shared_ptr<symbol::Symbol> API::lookup(uint32_t id) {
+  return symbols[ids[id]];
+}
+
+void API::setIntrinsic(Handle h, std::shared_ptr<symbol::Symbol> s) {
+  auto i = std::static_pointer_cast<symbol::Intrinsic>(s);
+  auto type = h->r8();
+  switch (type) {
+    case symbol::Intrinsic::U8:
+      i->type = symbol::Intrinsic::U8;
+      break;
+    case symbol::Intrinsic::U16:
+      i->type = symbol::Intrinsic::U16;
+      break;
+    case symbol::Intrinsic::U32:
+      i->type = symbol::Intrinsic::U32;
+      break;
+    case symbol::Intrinsic::S8:
+      i->type = symbol::Intrinsic::S8;
+      break;
+    case symbol::Intrinsic::S16:
+      i->type = symbol::Intrinsic::S16;
+      break;
+    case symbol::Intrinsic::S32:
+      i->type = symbol::Intrinsic::S32;
+      break;
+  }
+}
+
+void API::setEnum(Handle h, std::shared_ptr<symbol::Symbol> s) {
+  auto e = std::static_pointer_cast<symbol::Enum>(s);
+  e->type = lookup(h->r32());
+  auto num = h->r32();
+  for (uint32_t i = 0; i < num; i++) {
+    auto value = h->r32();
+    e->entries[h->rs()] = value;
+  }
+}
+
+void API::setRef(Handle h, std::shared_ptr<symbol::Symbol> s) {
+  auto r = std::static_pointer_cast<symbol::Ref>(s);
+  auto id = h->r32();
+  if (id == 0) {
+    r->symbol = nullptr;
+  } else {
+    r->symbol = lookup(id);
+    r->pointer = h->r32();
+    r->array = static_cast<int32_t>(h->r32());
+    r->reg = h->rs();
+  }
+}
+
+void API::setStruct(Handle h, std::shared_ptr<symbol::Symbol> s) {
+  auto str = std::static_pointer_cast<symbol::Struct>(s);
+  auto numFields = h->r32();
+  for (uint32_t i = 0; i < numFields; i++) {
+    auto key = h->rs();
+    auto kind = h->r8();
+    auto size = h->r32();
+    std::shared_ptr<symbol::Symbol> sym = nullptr;
+    switch (kind) {
+      case symbol::isRef:
+        sym = std::make_shared<symbol::Ref>();
+        sym->kind = symbol::isRef;
+        sym->size = size;
+        setRef(h, sym);
+        break;
+      case symbol::isStruct:
+        sym = std::make_shared<symbol::Struct>();
+        sym->kind = symbol::isStruct;
+        sym->size = size;
+        setStruct(h, sym);
+        break;
+      case symbol::isUnion:
+        sym = std::make_shared<symbol::Struct>();
+        sym->kind = symbol::isUnion;
+        sym->size = size;
+        setStruct(h, sym);
+        break;
+      default:
+        std::cerr << "Unknown field type" << std::endl;
+        break;
+    }
+    str->fields.push_back({key, sym});
+  }
+}
+
+void API::setFunction(Handle h, std::shared_ptr<symbol::Symbol> s) {
+  auto f = std::static_pointer_cast<symbol::Function>(s);
+  auto numArgs = h->r32();
+  for (uint32_t i = 0; i < numArgs; i++) {
+    auto key = h->rs();
+    auto ref = std::make_shared<symbol::Ref>();
+    setRef(h, ref);
+    f->arguments.push_back({key, ref});
+  }
+  f->returnType = std::make_shared<symbol::Ref>();
+  setRef(h, f->returnType);
+  auto numSig = h->r32();
+  for (uint32_t i = 0; i < numSig; i++) {
+    f->signature.push_back(h->r32());
+  }
+}
diff --git a/src/api.h b/src/api.h
new file mode 100644
index 0000000..38e4011
--- /dev/null
+++ b/src/api.h
@@ -0,0 +1,86 @@
+/** @copyright 2020 Sean Kasun */
+#pragma once
+
+#include <cstdint>
+#include <map>
+#include "handle.h"
+
+struct Fingerprint {
+  std::map<uint8_t, std::shared_ptr<Fingerprint>> map;
+  uint8_t numDB;
+  std::string name;
+};
+
+class Fingerprints {
+ public:
+  Fingerprints();
+  void add(const std::vector<uint8_t> &keys, std::string name,
+           uint8_t numDB = 0);
+  std::shared_ptr<Fingerprint> root;
+};
+
+namespace symbol {
+
+enum Kind {
+  isIntrinsic = 0, isEnum, isAlias, isStruct, isUnion, isRef, isFunction,
+};
+
+struct Symbol {
+  std::string name;
+  uint32_t size;
+  Kind kind;
+};
+
+struct Ref : public Symbol {
+  std::shared_ptr<Symbol> symbol;
+  uint32_t pointer;
+  int32_t array;
+  std::string reg;
+};
+
+struct Argument {
+  std::string key;
+  std::shared_ptr<Ref> ref;
+};
+
+struct Function : public Symbol {
+  std::vector<Argument> arguments;
+  std::shared_ptr<Ref> returnType;
+  std::vector<uint32_t> signature;
+};
+
+struct Field {
+  std::string key;
+  std::shared_ptr<Symbol> value;
+};
+
+struct Struct : public Symbol {
+  std::vector<Field> fields;
+};
+
+struct Intrinsic : public Symbol {
+  enum uint8_t { U8, U16, U23, S8, S16, S32 } type;
+};
+
+struct Enum : public Symbol {
+  std::shared_ptr<Symbol> type;
+  std::map<std::string, uint32_t> entries;
+};
+
+}
+
+class API {
+ public:
+  API(unsigned char *dat, unsigned int len);
+  std::map<std::string, std::shared_ptr<symbol::Symbol>> symbols;
+
+ private:
+  std::shared_ptr<symbol::Symbol> lookup(uint32_t id);
+  void setIntrinsic(Handle h, std::shared_ptr<symbol::Symbol> s);
+  void setEnum(Handle h, std::shared_ptr<symbol::Symbol> s);
+  void setRef(Handle h, std::shared_ptr<symbol::Symbol> s);
+  void setStruct(Handle h, std::shared_ptr<symbol::Symbol> s);
+  void setFunction(Handle h, std::shared_ptr<symbol::Symbol> s);
+
+  std::map<uint32_t, std::string> ids;
+};
diff --git a/src/disasm.cc b/src/disasm.cc
new file mode 100644
index 0000000..68f497b
--- /dev/null
+++ b/src/disasm.cc
@@ -0,0 +1,127 @@
+/** @copyright 2020 Sean Kasun */
+
+#include "disasm.h"
+#include <fstream>
+#include <iostream>
+
+Disassembler::Disassembler(std::shared_ptr<Fingerprints> prints) : fingerprints(prints) { }
+
+bool Disassembler::disassemble(std::vector<Segment> segments,
+                          std::vector<Entry> entries) {
+  this->segments = segments;
+  // trace all entry points
+  for (auto &entry : entries) {
+    if (!trace(entry)) {
+      std::cerr << "Failed to trace execution flow" << std::endl;
+      return false;
+    }
+  }
+  // build the basic blocks
+  if (!basicBlocks()) {
+    std::cerr << "Failed to calculate basic blocks" << std::endl;
+    return false;
+  }
+  // disassemble each segment
+  for (auto &segment : segments) {
+    std::string fname = "seg" + std::to_string(segment.segnum);
+    std::ofstream f(fname, std::ios::out | std::ios::binary | std::ios::trunc);
+    if (!f.is_open()) {
+      std::cerr << "Failed to open '" << fname << "' for writing" << std::endl;
+      return false;
+    }
+    f << "Section $" << std::ios::hex << segment.segnum << " "
+      << segment.name << std::endl;
+    if (!decode(segment.mapped, segment.mapped + segment.length)) {
+      std::cerr << "Disassembly failed" << std::endl;
+      return false;
+    }
+    f.close();
+  }
+  return true;
+}
+
+bool Disassembler::trace(const Entry &start) {
+  std::stack<Entry> workList;
+
+  workList.push(start);
+  labels.insert(std::pair<uint32_t, uint32_t>(start.org, start.org));
+  while (!workList.empty()) {
+    auto state = workList.top();
+    workList.pop();
+    std::shared_ptr<Inst> inst = nullptr;
+    do {
+      auto ptr = getAddress(state.org);
+      if (ptr == nullptr) {
+        return false;
+      }
+      auto addr = state.org;
+      inst = nullptr;
+      int16_t numDB = 0;
+      if (fingerprints) {  // scan for fingerprints
+        auto node = fingerprints->root;
+        int8_t len = 0;
+        auto fstart = ptr->tell();
+        do {
+          node = node->map.value(ptr->r8(), nullptr);
+          len++;
+          if (node != nullptr && !node->name.isEmpty()) {
+            if (inst == nullptr) {
+              inst = std::make_shared<Inst>();
+              inst->type = Special;
+            }
+            inst->name = node->name;
+            inst->length = len;
+            numDB = node->numDB;
+          }
+        } while (node != nullptr && !ptr->eof());
+        if (inst) {
+          fstart += inst->length;
+          state.org += inst->length;
+        }
+        ptr->seek(fstart);
+      }
+      if (numDB > 0 && inst) {
+        inst->name += " {";
+        for (int i = 0; i < numDB; i++) {
+          if (i) {
+            inst->name += ", ";
+          }
+          inst->name += hex2(ptr->r8());
+        }
+        inst->name += "}";
+        inst->length += numDB;
+        state.org += numDB;
+      }
+      if (!inst) {
+        inst = decodeInst(ptr, &state);
+      }
+      map[addr] = inst;
+      if (inst->type == Jump || inst->type == Branch || inst->type == Call) {
+        auto target = target(inst, resolver);
+        if (target > 0 && !labels.contains(target)) {
+          workList.push({state.flags, target});
+          labels.insert(target, target);
+        }
+      }
+      if (inst->type == Jump || inst->type == Branch ||
+          inst->type == Return) {
+        branches.insert(state.org, addr);
+      }
+      if (inst->type == Invalid) {
+        branches.insert(addr, addr);
+      }
+    } while (inst->type != Return && inst->type != Jump &&
+             inst->type != Invalid);
+  }
+  return true;
+}
+
+Handle Disassembler::getAddress(uint32_t address) {
+  for (auto &s : segments) {
+    if (address >= s.mapped && address < s.mapped + s.length) {
+      s.data->seek(address - s.mapped);
+      return s.data;
+    }
+  }
+  return nullptr;
+}
diff --git a/src/disasm.h b/src/disasm.h
index 1c10ff8..13aa243 100644
--- a/src/disasm.h
+++ b/src/disasm.h
@@ -2,6 +2,9 @@
 #pragma once
 
 #include <cstdint>
+#include <map>
+#include "omf.h"
+#include "api.h"
 
 enum {
   IsX8 = 0x10,
@@ -12,3 +15,34 @@ enum {
   IsM8Changed = 0x400,
   IsEmuChanged = 0x2000,
 };
+
+enum InsType : uint16_t {
+  Normal = 0x00,
+  Call = 0x01,
+  Jump = 0x02,
+  Return = 0x03,
+  Branch = 0x04,
+  Special = 0x05,  // fingerprint
+  Invalid = 0xff,
+};
+
+struct Inst {
+  std::string name;
+  InsType type;
+  uint16_t length;
+};
+
+class Disassembler {
+ public:
+  Disassembler(std::shared_ptr<Fingerprints> prints);
+  bool disassemble(std::vector<Segment> segments, std::vector<Entry> entries);
+
+ private:
+  bool trace(const Entry &start);
+  Handle getAddress(uint32_t address);
+
+  std::map<uint32_t, uint32_t> labels;
+  std::map<uint32_t, uint32_t> branches;
+  std::vector<Segment> segments;
+  std::shared_ptr<Fingerprints> fingerprints;
+};
diff --git a/src/handle.cc b/src/handle.cc
index a188fd5..9760b4d 100644
--- a/src/handle.cc
+++ b/src/handle.cc
@@ -68,6 +68,15 @@ uint8_t TheHandle::r8() {
   return *pos++;
 }
 
+std::string TheHandle::rs() {
+  std::string r;
+  uint8_t len = *pos++;
+  for (auto i = 0; i < len; i++) {
+    r += static_cast<char>(*pos++);
+  }
+  return r;
+}
+
 std::string TheHandle::read(int32_t len) {
   std::string r;
   for (auto i = 0; i < len; i++) {
diff --git a/src/handle.h b/src/handle.h
index 525a0c6..2607112 100644
--- a/src/handle.h
+++ b/src/handle.h
@@ -19,6 +19,7 @@ class TheHandle {
   uint32_t r24();
   uint16_t r16();
   uint8_t r8();
+  std::string rs();
   void seek(int64_t pos);
   void skip(int64_t length);
   std::string read(int32_t length);
diff --git a/src/main.cc b/src/main.cc
index 96c0bb9..31b5bd5 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -4,7 +4,8 @@
 #include <iostream>
 #include "disasm.h"
 #include "omf.h"
-
+#include "api.h"
+#include "../iigs.c"
 
 const char *argp_program_version = "regs 0.2";
 const char *argp_program_bug_address = "sean@seancode.com";
@@ -109,11 +110,54 @@ int main(int argc, char **argv) {
   argp_parse(&argp, argc, argv, 0, 0, &arguments);
 
   // load map if it exists
-  Map map(arguments.filename, arguments.org, arguments.flags);
-  OMF omf(map);
-  if (!omf.load(arguments.filename)) {
+  Map map(arguments.filename);
+  OMF omf;
+  if (!omf.load(arguments.filename, arguments.org)) {
     std::cerr << "Failed to load " << arguments.filename << std::endl;
     return -1;
   }
   auto segments = omf.get();
+  if (map.needsEntry()) {
+    for (auto &s : segments) {
+      if ((s.kind & 0x1f) == 0) {  // code
+        map.addEntry(s.mapped + s.entry, arguments.flags);
+        break;
+      }
+    }
+  }
+
+  API api(iigs_dat, iigs_dat_len);
+
+  auto prints = std::make_shared<Fingerprints>();
+  for (auto s : api.symbols) {
+    if (s->kind == symbol::isFunction) {
+      auto f = std::static_pointer_cast<symbol::Function>(s);
+      if (f->signature.size() >= 2) {
+        if (f->signature[0] >= 0) {  // tool
+          // ldx tool, jsl e1/0000
+          std::vector<uint8_t> sig = { 0xa2, f->signature[0], f->signature[1],
+            0x22, 0x00, 0x00, 0xe1 };
+          prints->add(sig, f->name);
+        } else if (f->signature[0] == -1) {  // p16/gsos
+          // jsl e1/00a8
+          std::vector<uint8_t> sig = { 0x22, 0xa8, 0x00, 0xe1,
+            f->signature[2] & 0xff, f->signature[2] >> 8 };
+          prints->add(sig, f->name, f->signature[1] & 0xff);
+        } else if (f->signature[0] == -2) {  // p8
+          // jsr bf00
+          std::vector<uint8_t> sig = { 0x20, 0x00, 0xbf, f->signature[2] };
+          prints->add(sig, f->name, f->signature[1] & 0xff);
+        } else if (f->signature[0] == -3) {  // smartport
+          // jsr c50d
+          std::vector<uint8_t> sig5 = { 0x20, 0x0d, 0xc5, f->signature[2] };
+          std::vector<uint8_t> sig7 = { 0x20, 0x0d, 0xc7, f->signature[2] };
+          prints->add(sig5, f->name, f->signature[1]);
+          prints->add(sig7, f->name, f->signature[1]);
+        }
+      }
+    }
+  }
+
+  Disassembler d(prints);
+  d.disassemble(segments, map.getEntries());
 }
diff --git a/src/map.cc b/src/map.cc
index 70e56aa..853b044 100644
--- a/src/map.cc
+++ b/src/map.cc
@@ -3,16 +3,11 @@
 #include <string>
 #include <fstream>
 
-Map::Map(const char *filename, uint32_t org, uint32_t flags) {
+Map::Map(const char *filename) {
   std::string mapname = filename;
   mapname += ".regs";
   File file(mapname);
   if (!file.is_open()) {
-    Entry entry;
-    entry.org = org;
-    this->org = org;
-    entry.flags = flags;
-    entryPoints.push_back(entry);
     return;
   }
 
@@ -54,10 +49,18 @@ Map::Map(const char *filename, uint32_t org, uint32_t flags) {
   }
 }
 
-void Map::addEntry(uint32_t entry) {
+bool Map::needsEntry() {
+  return entryPoints.size() == 0;
+}
+
+std::vector<Entry> Map::getEntries() {
+  return entryPoints;
+}
+
+void Map::addEntry(uint32_t entry, uint32_t flags) {
   Entry e;
   e.org = entry;
-  e.flags = 0;
+  e.flags = flags;
   entryPoints.push_back(e);
 }
 
diff --git a/src/map.h b/src/map.h
index 48a9a36..5aa2c23 100644
--- a/src/map.h
+++ b/src/map.h
@@ -31,8 +31,10 @@ struct Entry {
 
 class Map {
  public:
-  Map(const char *filename, uint32_t org, uint32_t flags);
-  void addEntry(uint32_t entry);
+  Map(const char *filename);
+  bool needsEntry();
+  std::vector<Entry> getEntries();
+  void addEntry(uint32_t entry, uint32_t flags);
   uint32_t org;
 
  private:
diff --git a/src/omf.cc b/src/omf.cc
index 3dd2cf8..713c2c7 100644
--- a/src/omf.cc
+++ b/src/omf.cc
@@ -13,21 +13,22 @@ enum SegOp {
   SUPER = 0xf7,
 };
 
-OMF::OMF(const Map &map) : map(map) {
+OMF::OMF() {
 }
 
 static bool compareSegments(const Segment &a, const Segment &b) {
   return a.mapped < b.mapped;
 }
 
-bool OMF::load(const char *filename) {
+bool OMF::load(const char *filename, uint32_t org) {
   handle = TheHandle::createFromFile(filename);
 
   if (!isOMF()) {
     Segment seg;
     seg.bytecnt = handle->length;
     seg.kind = 0;  // code
-    seg.mapped = map.org;
+    seg.entry = 0;
+    seg.mapped = org;
     seg.data = handle;
     segments.push_back(seg);
   } else {
@@ -40,13 +41,6 @@ bool OMF::load(const char *filename) {
     if (!relocSegments()) {
       return false;
     }
-    // add the first entry point
-    for (auto &s : segments) {
-      if ((s.kind & 0x1f) == 0) {  // code
-        map.addEntry(s.mapped + s.entry);
-        break;
-      }
-    }
   }
   std::sort(segments.begin(), segments.end(), compareSegments);
   return true;
diff --git a/src/omf.h b/src/omf.h
index f8b01f2..37afe27 100644
--- a/src/omf.h
+++ b/src/omf.h
@@ -26,8 +26,8 @@ struct Segment {
 
 class OMF {
  public:
-  explicit OMF(const Map &map);
-  bool load(const char *filename);
+  explicit OMF();
+  bool load(const char *filename, uint32_t org);
   std::vector<Segment> get() const;
 
  private:
@@ -39,6 +39,5 @@ class OMF {
              uint32_t value);
 
   Handle handle;
-  const Map &map;
   std::vector<Segment> segments;
 };