diff --git a/cmd/ethereum/main.go b/cmd/ethereum/main.go
index 7e67a6dcca..c39f904fb3 100644
--- a/cmd/ethereum/main.go
+++ b/cmd/ethereum/main.go
@@ -22,8 +22,8 @@ import (
 	"os"
 	"runtime"
 
-	"github.com/ethereum/go-ethereum/chain/types"
 	"github.com/ethereum/go-ethereum/cmd/utils"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethutil"
 	"github.com/ethereum/go-ethereum/logger"
 )
diff --git a/core/chain_manager_test.go b/core/chain_manager_test.go
index 51e70fb12c..ab43c511da 100644
--- a/core/chain_manager_test.go
+++ b/core/chain_manager_test.go
@@ -6,7 +6,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/ethereum/go-ethereum/chain/types"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/ethutil"
 	"github.com/ethereum/go-ethereum/state"
diff --git a/core/helper_test.go b/core/helper_test.go
index 2b1510ea49..b340144fdd 100644
--- a/core/helper_test.go
+++ b/core/helper_test.go
@@ -4,7 +4,7 @@ import (
 	"container/list"
 	"fmt"
 
-	"github.com/ethereum/go-ethereum/chain/types"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/ethutil"
diff --git a/tests/helper/vm.go b/tests/helper/vm.go
index 6ee50a5ae0..e0d5adb15e 100644
--- a/tests/helper/vm.go
+++ b/tests/helper/vm.go
@@ -3,7 +3,7 @@ package helper
 import (
 	"math/big"
 
-	"github.com/ethereum/go-ethereum/chain"
+	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethutil"
 	"github.com/ethereum/go-ethereum/state"
@@ -66,9 +66,9 @@ func (self *Env) Transfer(from, to vm.Account, amount *big.Int) error {
 	return vm.Transfer(from, to, amount)
 }
 
-func (self *Env) vm(addr, data []byte, gas, price, value *big.Int) *chain.Execution {
+func (self *Env) vm(addr, data []byte, gas, price, value *big.Int) *core.Execution {
 	evm := vm.New(self, vm.DebugVmTy)
-	exec := chain.NewExecution(evm, addr, data, gas, price, value)
+	exec := core.NewExecution(evm, addr, data, gas, price, value)
 	exec.SkipTransfer = self.skipTransfer
 
 	return exec
diff --git a/tests/vm/gh_test.go b/tests/vm/gh_test.go
index 5c4df19757..3da37cd3ad 100644
--- a/tests/vm/gh_test.go
+++ b/tests/vm/gh_test.go
@@ -6,7 +6,7 @@ import (
 	"strconv"
 	"testing"
 
-	"github.com/ethereum/go-ethereum/chain/types"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethutil"
 	"github.com/ethereum/go-ethereum/state"
 	"github.com/ethereum/go-ethereum/tests/helper"
diff --git a/vm/analysis.go b/vm/analysis.go
index 52c7143e09..fef448b7ba 100644
--- a/vm/analysis.go
+++ b/vm/analysis.go
@@ -6,17 +6,17 @@ import (
 	"github.com/ethereum/go-ethereum/ethutil"
 )
 
-func analyseJumpDests(code []byte) (dests map[int64]*big.Int) {
-	dests = make(map[int64]*big.Int)
+func analyseJumpDests(code []byte) (dests map[uint64]*big.Int) {
+	dests = make(map[uint64]*big.Int)
 
 	lp := false
 	var lpv *big.Int
-	for pc := int64(0); pc < int64(len(code)); pc++ {
+	for pc := uint64(0); pc < uint64(len(code)); pc++ {
 		var op OpCode = OpCode(code[pc])
 		switch op {
 		case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
-			a := int64(op) - int64(PUSH1) + 1
-			if int64(len(code)) > pc+1+a {
+			a := uint64(op) - uint64(PUSH1) + 1
+			if uint64(len(code)) > pc+1+a {
 				lpv = ethutil.BigD(code[pc+1 : pc+1+a])
 			}
 
diff --git a/vm/closure.go b/vm/closure.go
index 5324ee1ece..bd5268f96f 100644
--- a/vm/closure.go
+++ b/vm/closure.go
@@ -41,16 +41,16 @@ func NewClosure(msg *state.Message, caller ClosureRef, object ClosureRef, code [
 	return c
 }
 
-func (c *Closure) GetValue(x *big.Int) *ethutil.Value {
-	return c.GetRangeValue(x, big.NewInt(1))
+func (c *Closure) GetValue(x uint64) *ethutil.Value {
+	return c.GetRangeValue(x, 1)
 }
 
-func (c *Closure) GetOp(x int) OpCode {
+func (c *Closure) GetOp(x uint64) OpCode {
 	return OpCode(c.GetByte(x))
 }
 
-func (c *Closure) GetByte(x int) byte {
-	if x > -1 && x < len(c.Code) {
+func (c *Closure) GetByte(x uint64) byte {
+	if x < uint64(len(c.Code)) {
 		return c.Code[x]
 	}
 
@@ -65,12 +65,12 @@ func (c *Closure) GetBytes(x, y int) []byte {
 	return c.Code[x : x+y]
 }
 
-func (c *Closure) GetRangeValue(x, y *big.Int) *ethutil.Value {
-	if x.Int64() >= int64(len(c.Code)) || y.Int64() >= int64(len(c.Code)) {
+func (c *Closure) GetRangeValue(x, y uint64) *ethutil.Value {
+	if x >= uint64(len(c.Code)) || y >= uint64(len(c.Code)) {
 		return ethutil.NewValue(0)
 	}
 
-	partial := c.Code[x.Int64() : x.Int64()+y.Int64()]
+	partial := c.Code[x : x+y]
 
 	return ethutil.NewValue(partial)
 }
diff --git a/vm/vm_debug.go b/vm/vm_debug.go
index cf234c4125..712af55fa3 100644
--- a/vm/vm_debug.go
+++ b/vm/vm_debug.go
@@ -75,35 +75,35 @@ func (self *DebugVm) Run(me, caller ClosureRef, code []byte, value, gas, price *
 	var (
 		op OpCode
 
-		destinations = analyseJumpDests(closure.Code)
-		mem          = NewMemory()
-		stack        = NewStack()
-		pc           = big.NewInt(0)
-		step         = 0
-		prevStep     = 0
-		statedb      = self.env.State()
-		require      = func(m int) {
+		destinations        = analyseJumpDests(closure.Code)
+		mem                 = NewMemory()
+		stack               = NewStack()
+		pc           uint64 = 0
+		step                = 0
+		prevStep            = 0
+		statedb             = self.env.State()
+		require             = func(m int) {
 			if stack.Len() < m {
 				panic(fmt.Sprintf("%04v (%v) stack err size = %d, required = %d", pc, op, stack.Len(), m))
 			}
 		}
 
-		jump = func(from, to *big.Int) {
-			p := int(to.Int64())
+		jump = func(from uint64, to *big.Int) {
+			p := to.Uint64()
 
 			self.Printf(" ~> %v", to)
 			// Return to start
 			if p == 0 {
-				pc = big.NewInt(0)
+				pc = 0
 			} else {
 				nop := OpCode(closure.GetOp(p))
-				if !(nop == JUMPDEST || destinations[from.Int64()] != nil) {
+				if !(nop == JUMPDEST || destinations[from] != nil) {
 					panic(fmt.Sprintf("JUMP missed JUMPDEST (%v) %v", nop, p))
 				} else if nop == JUMP || nop == JUMPI {
 					panic(fmt.Sprintf("not allowed to JUMP(I) in to JUMP"))
 				}
 
-				pc = to
+				pc = to.Uint64()
 
 			}
 
@@ -125,26 +125,28 @@ func (self *DebugVm) Run(me, caller ClosureRef, code []byte, value, gas, price *
 
 		step++
 		// Get the memory location of pc
-		op = closure.GetOp(int(pc.Uint64()))
+		op = closure.GetOp(pc)
+
+		/*
+			// XXX Leave this Println intact. Don't change this to the log system.
+			// Used for creating diffs between implementations
+			if self.logTy == LogTyDiff {
+				switch op {
+				case STOP, RETURN, SUICIDE:
+					statedb.GetStateObject(closure.Address()).EachStorage(func(key string, value *ethutil.Value) {
+						value.Decode()
+						fmt.Printf("%x %x\n", new(big.Int).SetBytes([]byte(key)).Bytes(), value.Bytes())
+					})
+				}
 
-		// XXX Leave this Println intact. Don't change this to the log system.
-		// Used for creating diffs between implementations
-		if self.logTy == LogTyDiff {
-			switch op {
-			case STOP, RETURN, SUICIDE:
-				statedb.GetStateObject(closure.Address()).EachStorage(func(key string, value *ethutil.Value) {
-					value.Decode()
-					fmt.Printf("%x %x\n", new(big.Int).SetBytes([]byte(key)).Bytes(), value.Bytes())
-				})
-			}
+				b := pc.Bytes()
+				if len(b) == 0 {
+					b = []byte{0}
+				}
 
-			b := pc.Bytes()
-			if len(b) == 0 {
-				b = []byte{0}
+				fmt.Printf("%x %x %x %x\n", closure.Address(), b, []byte{byte(op)}, closure.Gas.Bytes())
 			}
-
-			fmt.Printf("%x %x %x %x\n", closure.Address(), b, []byte{byte(op)}, closure.Gas.Bytes())
-		}
+		*/
 
 		gas := new(big.Int)
 		addStepGasUsage := func(amount *big.Int) {
@@ -735,13 +737,15 @@ func (self *DebugVm) Run(me, caller ClosureRef, code []byte, value, gas, price *
 
 			// 0x50 range
 		case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
-			a := big.NewInt(int64(op) - int64(PUSH1) + 1)
-			pc.Add(pc, ethutil.Big1)
-			data := closure.GetRangeValue(pc, a)
+			//a := big.NewInt(int64(op) - int64(PUSH1) + 1)
+			a := uint64(op - PUSH1 + 1)
+			//pc.Add(pc, ethutil.Big1)
+			data := closure.GetRangeValue(pc+1, a)
 			val := ethutil.BigD(data.Bytes())
 			// Push value to stack
 			stack.Push(val)
-			pc.Add(pc, a.Sub(a, big.NewInt(1)))
+			pc += a
+			//pc.Add(pc, a.Sub(a, big.NewInt(1)))
 
 			step += int(op) - int(PUSH1) + 1
 
@@ -750,13 +754,9 @@ func (self *DebugVm) Run(me, caller ClosureRef, code []byte, value, gas, price *
 			stack.Pop()
 		case DUP1, DUP2, DUP3, DUP4, DUP5, DUP6, DUP7, DUP8, DUP9, DUP10, DUP11, DUP12, DUP13, DUP14, DUP15, DUP16:
 			n := int(op - DUP1 + 1)
-			v := stack.Dupn(n)
+			stack.Dupn(n)
 
 			self.Printf(" => [%d] 0x%x", n, stack.Peek().Bytes())
-
-			if OpCode(closure.GetValue(new(big.Int).Add(pc, ethutil.Big1)).Uint()) == POP && OpCode(closure.GetValue(new(big.Int).Add(pc, big.NewInt(2))).Uint()) == POP {
-				fmt.Println(toValue(v))
-			}
 		case SWAP1, SWAP2, SWAP3, SWAP4, SWAP5, SWAP6, SWAP7, SWAP8, SWAP9, SWAP10, SWAP11, SWAP12, SWAP13, SWAP14, SWAP15, SWAP16:
 			n := int(op - SWAP1 + 2)
 			x, y := stack.Swapn(n)
@@ -811,7 +811,6 @@ func (self *DebugVm) Run(me, caller ClosureRef, code []byte, value, gas, price *
 
 			self.Printf(" {0x%x : 0x%x}", loc.Bytes(), val.Bytes())
 		case JUMP:
-
 			jump(pc, stack.Pop())
 
 			continue
@@ -826,7 +825,7 @@ func (self *DebugVm) Run(me, caller ClosureRef, code []byte, value, gas, price *
 
 		case JUMPDEST:
 		case PC:
-			stack.Push(pc)
+			stack.Push(big.NewInt(int64(pc)))
 		case MSIZE:
 			stack.Push(big.NewInt(int64(mem.Len())))
 		case GAS:
@@ -940,13 +939,13 @@ func (self *DebugVm) Run(me, caller ClosureRef, code []byte, value, gas, price *
 			return closure.Return(nil), fmt.Errorf("Invalid opcode %x", op)
 		}
 
-		pc.Add(pc, ethutil.Big1)
+		pc++
 
 		self.Endl()
 
 		if self.Dbg != nil {
 			for _, instrNo := range self.Dbg.BreakPoints() {
-				if pc.Cmp(big.NewInt(instrNo)) == 0 {
+				if pc == uint64(instrNo) {
 					self.Stepping = true
 
 					if !self.Dbg.BreakHook(prevStep, op, mem, stack, statedb.GetStateObject(closure.Address())) {
diff --git a/xeth/pipe.go b/xeth/pipe.go
index cabcc1cbe3..f1ecd19d5e 100644
--- a/xeth/pipe.go
+++ b/xeth/pipe.go
@@ -39,6 +39,9 @@ func New(obj core.EthManager) *XEth {
 	return pipe
 }
 
+/*
+ * State / Account accessors
+ */
 func (self *XEth) Balance(addr []byte) *ethutil.Value {
 	return ethutil.NewValue(self.World().safeGet(addr).Balance)
 }
@@ -47,32 +50,6 @@ func (self *XEth) Nonce(addr []byte) uint64 {
 	return self.World().safeGet(addr).Nonce
 }
 
-func (self *XEth) Execute(addr []byte, data []byte, value, gas, price *ethutil.Value) ([]byte, error) {
-	return self.ExecuteObject(&Object{self.World().safeGet(addr)}, data, value, gas, price)
-}
-
-func (self *XEth) ExecuteObject(object *Object, data []byte, value, gas, price *ethutil.Value) ([]byte, error) {
-	var (
-		initiator = state.NewStateObject(self.obj.KeyManager().KeyPair().Address())
-		block     = self.blockChain.CurrentBlock
-	)
-
-	self.Vm.State = self.World().State().Copy()
-
-	vmenv := NewEnv(self.Vm.State, block, value.BigInt(), initiator.Address())
-	return vmenv.Call(initiator, object.Address(), data, gas.BigInt(), price.BigInt(), value.BigInt())
-	/*
-		evm := vm.New(, vm.Type(ethutil.Config.VmType))
-
-		msg := vm.NewExecution(evm, object.Address(), data, gas.BigInt(), price.BigInt(), value.BigInt())
-		ret, err := msg.Exec(object.Address(), initiator)
-
-		fmt.Println("returned from call", ret, err)
-
-		return ret, err
-	*/
-}
-
 func (self *XEth) Block(hash []byte) *types.Block {
 	return self.blockChain.GetBlock(hash)
 }
@@ -81,6 +58,11 @@ func (self *XEth) Storage(addr, storageAddr []byte) *ethutil.Value {
 	return self.World().safeGet(addr).GetStorage(ethutil.BigD(storageAddr))
 }
 
+func (self *XEth) Exists(addr []byte) bool {
+	return self.World().Get(addr) != nil
+}
+
+// Converts the given private key to an address
 func (self *XEth) ToAddress(priv []byte) []byte {
 	pair, err := crypto.NewKeyPairFromSec(priv)
 	if err != nil {
@@ -90,10 +72,28 @@ func (self *XEth) ToAddress(priv []byte) []byte {
 	return pair.Address()
 }
 
-func (self *XEth) Exists(addr []byte) bool {
-	return self.World().Get(addr) != nil
+/*
+ * Execution helpers
+ */
+func (self *XEth) Execute(addr []byte, data []byte, value, gas, price *ethutil.Value) ([]byte, error) {
+	return self.ExecuteObject(&Object{self.World().safeGet(addr)}, data, value, gas, price)
+}
+
+func (self *XEth) ExecuteObject(object *Object, data []byte, value, gas, price *ethutil.Value) ([]byte, error) {
+	var (
+		initiator = state.NewStateObject(self.obj.KeyManager().KeyPair().Address())
+		block     = self.blockChain.CurrentBlock
+	)
+
+	self.Vm.State = self.World().State().Copy()
+
+	vmenv := NewEnv(self.Vm.State, block, value.BigInt(), initiator.Address())
+	return vmenv.Call(initiator, object.Address(), data, gas.BigInt(), price.BigInt(), value.BigInt())
 }
 
+/*
+ * Transactional methods
+ */
 func (self *XEth) TransactString(key *crypto.KeyPair, rec string, value, gas, price *ethutil.Value, data []byte) (*types.Transaction, error) {
 	// Check if an address is stored by this address
 	var hash []byte
@@ -149,13 +149,6 @@ func (self *XEth) Transact(key *crypto.KeyPair, to []byte, value, gas, price *et
 	}
 
 	return tx, nil
-
-	//acc := self.blockManager.TransState().GetOrNewStateObject(key.Address())
-	//self.obj.TxPool().QueueTransaction(tx)
-
-	//acc.Nonce += 1
-	//self.blockManager.TransState().UpdateStateObject(acc)
-
 }
 
 func (self *XEth) PushTx(tx *types.Transaction) ([]byte, error) {