diff --git a/tests/manyloc/gbemulator/cpu.nim b/tests/manyloc/gbemulator/cpu.nim
new file mode 100644
index 0000000000..da615065a4
--- /dev/null
+++ b/tests/manyloc/gbemulator/cpu.nim
@@ -0,0 +1,392 @@
+# Part of the Nimrod Gameboy emulator.
+# Copyright (C) Dominik Picheta.
+import mem, gpu
+import strutils
+type
+  # m (machine cycles), t (time cycles).
+  # Ref: http://www.zilog.com/docs/z80/um0080.pdf
+  TClock = tuple[m, t: int]
+
+  PRegister = ref object
+    pc, sp: int32 # 16-bit
+    a, b, c, d, e, H, L, f: int32 # 8-bit
+    clock: TClock
+
+  PCPU = ref object
+    clock: TClock
+    r: PRegister
+    mem: PMem
+
+  TFlagState = enum
+    FUnchanged, FSet, FUnset
+
+const
+  BitZ = 1 shl 7
+  BitN = 1 shl 6
+  BitH = 1 shl 5
+  BitC = 1 shl 4
+
+## Flags
+## -----
+## 0x80 (1 shl 7) - (Zero|Z) Last result was zero.
+## 0x40 (1 shl 6) - (Operation|N) Set if last operation was a subtraction
+## 0x20 (1 shl 5) - (Half carry|H)
+## 0x10 (1 shl 4) - (Carry|C)
+## 0x08 (1 shl 3) - (Sign flag|S)               NOT USED IN GB's Z80
+## 0x04 (1 shl 2) - (Parity/Overflow Flag|P/V)  NOT USED IN GB's Z80
+
+proc newCPU(mem: PMem): PCPU =
+  new(result)
+  new(result.r)
+  result.mem = mem
+
+# Split a 16-bit into 8-bit: let (a, b) = (x shr 8 and 0xff, x and 0xff)
+
+template changeFlag(f: var int32, state: TFlagState, bit: int32)  =
+  case state
+  of FSet:
+    f = f or bit
+  of FUnset:
+    f = f and (not bit)
+  else: assert false
+
+template changeFlags(cpu: PCPU, Z = FUnchanged, N = FUnchanged,
+                     H = FUnchanged, C = FUnchanged) =
+  if Z != FUnchanged: changeFlag(cpu.r.f, Z, BitZ)
+  if N != FUnchanged: changeFlag(cpu.r.f, N, BitN)
+  if H != FUnchanged: changeFlag(cpu.r.f, H, BitH)
+  if C != FUnchanged: changeFlag(cpu.r.f, C, BitC)
+
+template isFSet(cpu: PCPU, bit: int32): bool = (cpu.r.f and bit) != 0
+
+proc `>>`(b: bool): TFlagState =
+  if b: return FSet
+  else: return FUnset
+
+proc `/<</`(v: int32, interval: int): int32 =
+  ## Circular shift 8-bit value left ``interval`` times.
+  let leftMost = v shr (8-interval)
+  result = ((v shl interval) or leftMost).int32
+  result = result and 0xFF
+
+template LDrn(cpu: PCPU, register: expr) {.immediate.} =
+  cpu.r.register = cpu.mem.readByte(cpu.r.pc)
+  inc(cpu.r.pc)
+  cpu.r.clock.m = 2
+
+template PUSHqq(cpu: PCPU, r1, r2: expr) {.immediate.} =
+  cpu.r.sp.dec
+  cpu.mem.writeByte(cpu.r.sp, cpu.r.r1)
+  cpu.r.sp.dec
+  cpu.mem.writeByte(cpu.r.sp, cpu.r.r2)
+  cpu.r.clock.m = 3
+
+template POPqq(cpu: PCPU, r1, r2: expr) {.immediate.} =
+  ## r1 = High, r2 = Low
+  cpu.r.r2 = cpu.mem.readByte(cpu.r.sp)
+  cpu.r.sp.inc
+  cpu.r.r1 = cpu.mem.readByte(cpu.r.sp)
+  cpu.r.sp.inc
+  cpu.r.clock.m = 3
+
+template RLr(cpu: PCPU, register: expr) {.immediate.} =
+  let bit7 = cpu.r.register shl 7
+  let prevCarry = cpu.isFSet(BitC)
+  cpu.r.register = cpu.r.register /<</ 1
+  if prevCarry: cpu.r.register = cpu.r.register or 1 # Set Bit 0
+  else: cpu.r.register = cpu.r.register and (not 1) # Unset bit 0
+  cpu.changeFlags(Z = >>(cpu.r.register == 0), H = FUnset, N = FUnset,
+                  C = >>(bit7 == 1))
+  cpu.r.clock.m = 2
+
+template INCrr(cpu: PCPU, r1, r2: expr, flags = false) {.immediate.} =
+  let x = ((cpu.r.r1 shl 8) or cpu.r.r2) + 1
+  let (hi, low) = (x shr 8 and 0xFF, x and 0xFF)
+  cpu.r.r2 = low; cpu.r.r1 = hi
+  if flags:
+    cpu.changeFlags(Z = >>(x == 0), H = >>((x and 0xF) == 0), N = FUnset)
+    cpu.r.clock.m = 3
+
+template DECr(cpu: PCPU, register: expr) {.immediate.} =
+  cpu.r.register = (cpu.r.register - 1) and 0xFF
+  cpu.changeFlags(Z = >>(cpu.r.register == 0),
+                  H = >>((cpu.r.register and 0xF) == 0xF),
+                  N = FSet)
+  
+  cpu.r.clock.m = 1
+
+proc LDSimple(cpu: PCPU, opcode: int32) =
+  ## All (simple) variants of the LD opcodes end up here.
+  ## Essentially what we want is a register to be copied to another register.
+  
+  case opcode
+  of 0x40 .. 0x45:
+    # LD B, B .. LD B, L
+    # TODO JUST USE A MACRO
+    assert false
+    
+  else: assert false
+
+proc exec(cpu: PCPU) =
+  ## Executes the next instruction
+  let opcode = cpu.mem.readByte(cpu.r.pc)
+  #echo("OPCODE: 0x", toHex(opcode, 2))
+  cpu.r.pc.inc()
+  case opcode
+  of 0x06:
+    # LD B, n
+    # Load 8-bit immediate into B
+    LDrn(cpu, b)
+  of 0x0E:
+    # LD C, n
+    # Load 8-bit immediate into C.
+    LDrn(cpu, c)
+  of 0x1E:
+    # LD E, n
+    LDrn(cpu, e)
+  of 0x2E:
+    # LD L, n
+    LDrn(cpu, L)
+  of 0x3E:
+    # LD A, n
+    # Load 8-bit immediate into A.
+    LDrn(cpu, a)
+
+  of 0x0C:
+    # INC c
+    # Increment C
+    cpu.r.c = (cpu.r.c + 1) and 0xFF
+    cpu.r.clock.m = 1
+    cpu.changeFlags(Z = >>(cpu.r.c == 0), H = >>((cpu.r.c and 0xF) == 0),
+                    N = FUnset)
+  
+  of 0x03:
+    # INC BC
+    INCrr(cpu, b, c, true)
+  of 0x13:
+    # INC DE
+    INCrr(cpu, d, e, true)
+  of 0x23:
+    # INC HL
+    # Increment 16-bit HL
+    INCrr(cpu, H, L, true)
+  
+  of 0x05:
+    # DEC B
+    # Decrement B
+    DECr(cpu, b)
+  of 0x0D:
+    # DEC C
+    DECr(cpu, c)
+  of 0x1D:
+    # DEC E
+    DECr(cpu, e)
+  of 0x2D:
+    # DEC L
+    DECr(cpu, L)
+  of 0x3D:
+    # DEC A
+    DECr(cpu, a)
+
+  of 0x11:
+    # LD DE, nn
+    # Load 16-bit immediate into DE
+    cpu.r.e = cpu.mem.readByte(cpu.r.pc)
+    cpu.r.d = cpu.mem.readByte(cpu.r.pc+1)
+    cpu.r.pc.inc(2)
+    cpu.r.clock.m = 3
+  
+  of 0x17:
+    # RL A
+    # Rotate A left.
+    RLr(cpu, a)
+  
+  of 0x1A:
+    # LD A, (DE)
+    # Load A from address pointed to by DE
+    cpu.r.a = cpu.mem.readByte((cpu.r.d shl 8) or cpu.r.e)
+    cpu.r.clock.m = 2
+    
+  of 0x20, 0x28:
+    # (0x20) JR NZ, n; Relative jump by signed immediate if last result was not zero
+    # (0x28) JR Z, n; Same as above, but when last result *was* zero.
+    var x = cpu.mem.readByte(cpu.r.pc)
+    if x > 127: x = -(((not x) + 1) and 255)
+    cpu.r.pc.inc
+    cpu.r.clock.m = 2
+    if (opcode == 0x20 and (not isFSet(cpu, BitZ))) or
+       (opcode == 0x28 and isFSet(cpu, BitZ)):
+      cpu.r.pc.inc(x); cpu.r.clock.m.inc 
+  of 0x18:
+    # JR n
+    # Relative jump by signed immediate
+    var x = cpu.mem.readByte(cpu.r.pc)
+    if x > 127: x = -(((not x) + 1) and 255)
+    cpu.r.pc.inc
+    cpu.r.pc.inc(x)
+    cpu.r.clock.m = 3
+ 
+  of 0x21:
+    # LD HL, nn
+    # Load 16-bit immediate into (registers) H and L
+    cpu.r.L = cpu.mem.readByte(cpu.r.pc)
+    cpu.r.H = cpu.mem.readByte(cpu.r.pc+1)
+    cpu.r.pc.inc(2)
+    cpu.r.clock.m = 3
+  of 0x22:
+    # LDI (HL), A
+    # Save A to address pointed by HL and increment HL.
+    cpu.mem.writeByte((cpu.r.h shl 8) or cpu.r.l, cpu.r.a)
+    INCrr(cpu, H, L)
+    # TODO: Should flags be changed? (Z80 ref says they should.)
+    # cpu.changeFlags(H = FUnset, N = FUnset)
+    cpu.r.clock.m = 2
+  
+  of 0x31:
+    # LD SP, nn
+    # Load 16-bit immediate into (register) SP
+    cpu.r.sp = cpu.mem.readWord(cpu.r.pc)
+    cpu.r.pc.inc(2)
+    cpu.r.clock.m = 3
+  of 0x32:
+    # LDD (HL), A
+    # Save A to address pointed by HL, and decrement HL
+    cpu.mem.writeByte((cpu.r.h shl 8) or cpu.r.l, cpu.r.a)
+    let x = ((cpu.r.h shl 8) or cpu.r.l) - 1
+    let (hi, low) = (x shr 8 and 0xFF, x and 0xFF)
+    cpu.r.L = low; cpu.r.H = hi
+    # TODO: Should flags be changed? (Z80 ref says they should.)
+    cpu.r.clock.m = 2
+  
+
+  of 0x7B:
+    # LD A, E; Copy E into A
+    cpu.r.a = cpu.r.e
+    cpu.r.clock.m = 1
+    
+  of 0x77:
+    # LD (HL), A
+    # Copy A to address pointed by HL
+    let HL = ((cpu.r.h shl 8) or cpu.r.L)
+    cpu.mem.writeByte(HL, cpu.r.a)
+    cpu.r.clock.m = 2
+  
+  of 0xAF:
+    # XOR A
+    # Logical XOR against (register) A
+    cpu.r.a = (cpu.r.a xor cpu.r.a) and 255 # If result is bigger than 255, will be set to 0
+    cpu.changeFlags(Z = >>(cpu.r.a == 0), H = FUnset, C = FUnset)
+    cpu.r.clock.m = 1
+  
+  of 0xC1:
+    # POP BC
+    # Pop 16-bit value into BC
+    POPqq(cpu, b, c)
+  of 0xD1:
+    # POP DE
+    POPqq(cpu, d, e)
+  of 0xE1:
+    # POP HL
+    POPqq(cpu, H, L)
+  of 0xF1:
+    # POP AF
+    POPqq(cpu, a, f)
+  of 0xC5:
+    # PUSH BC
+    # Push 16-bit BC onto stack.
+    PUSHqq(cpu, b, c)
+  of 0xD5:
+    # PUSH DE
+    PUSHqq(cpu, d, e)
+  of 0xE5:
+    # PUSH HL
+    PUSHqq(cpu, H, L)
+  of 0xF5:
+    # PUSH AF
+    PUSHqq(cpu, a, f)
+  
+  of 0xC9:
+    # RET
+    # Return to calling routine.
+    cpu.r.pc = cpu.mem.readWord(cpu.r.sp)
+    cpu.r.sp.inc(2)
+    cpu.r.clock.m = 3
+  
+  of 0xCB:
+    # Extended Ops
+    let extop = cpu.mem.readByte(cpu.r.pc)
+    cpu.r.pc.inc
+    case extop
+    of 0x11:
+      # RL C
+      # Rotate C left.
+      RLr(cpu, c)
+    of 0x7C:
+      # BIT 7, H
+      # Test whether bit 7 of H is zero
+      cpu.changeFlags(Z = >>((cpu.r.h and (1 shl 7)) == 0), H = FSet, N = FUnset)
+      cpu.r.clock.m = 2
+    else:
+      echo "Unknown extended op: 0x", extop.toHex(2)
+      assert false
+  
+  of 0xCD:
+    # CALL nn
+    # Call routine at 16-bit location
+    cpu.r.sp.dec(2)
+    
+    # We pushing pc+2 onto the stack because the next two bits are used. Below next line.
+    cpu.mem.writeWord(cpu.r.sp, cpu.r.pc+2)
+    cpu.r.pc = cpu.mem.readWord(cpu.r.pc)
+    cpu.r.clock.m = 5
+  of 0xE0:
+    # LDH (0xFF00 + n), A
+    # Save A at address pointed to by (0xFF00 + 8-bit immediate).
+    cpu.mem.writeByte(0xFF00 + cpu.mem.readByte(cpu.r.pc), cpu.r.a)
+    cpu.r.pc.inc
+    cpu.r.clock.m = 3
+  
+  of 0xE2:
+    # LDH (0xFF00 + C), A
+    # Save A at address pointed to by 0xFF00+C
+    cpu.mem.writeByte(0xFF00 + cpu.r.c, cpu.r.a)
+    cpu.r.clock.m = 2
+  
+  of 0xFE:
+    # CP n; compare 8-bit immediate against A.
+    # TODO: This may be wrong. Review.
+    
+    var n = cpu.mem.readByte(cpu.r.pc)
+    var sum = cpu.r.a - n
+    let isNegative = sum < 0
+    sum = sum and 0xFF
+    
+    cpu.r.pc.inc
+    cpu.changeFlags(C = >>isNegative, Z = >>(sum == 0), N = FSet, 
+                    H = >>((sum and 0xF) > (cpu.r.a and 0xF)))
+    cpu.r.clock.m = 2
+  
+  of 0xEA:
+    # LD (nn), A; Save A at given 16-bit address.
+    cpu.mem.writeByte(cpu.mem.readWord(cpu.r.pc), cpu.r.a)
+    cpu.r.pc.inc(2)
+    cpu.r.clock.m = 4
+  
+  of 0x40 .. 0x45, 0x50 .. 0x55, 0x60 .. 0x65, 0x47 .. 0x4D, 0x57 .. 0x5D,
+     0x67 .. 0x6D, 0x78 .. 0x7D, 0x4F, 0x5F, 0x6F, 0x7F:
+    # Simple LD instructions. (Copy register1 to register2)
+    LDSimple(cpu, opcode)
+  
+  else:
+    echo "Unknown opcode: 0x", opcode.toHex(2)
+    assert false
+
+proc next*(cpu: PCPU) =
+  cpu.exec()
+  cpu.mem.gpu.next(cpu.r.clock.m)
+
+
+when isMainModule:
+  var cpu = newCpu(mem.load("/home/dom/code/nimrod/gbemulator/Pokemon_Red.gb"))
+  while True:
+    cpu.next()
\ No newline at end of file
diff --git a/tests/manyloc/gbemulator/cpu.nimrod.cfg b/tests/manyloc/gbemulator/cpu.nimrod.cfg
new file mode 100644
index 0000000000..1119d356ba
--- /dev/null
+++ b/tests/manyloc/gbemulator/cpu.nimrod.cfg
@@ -0,0 +1,2 @@
+# This config file marks 'cpu' as the main module.
+
diff --git a/tests/manyloc/gbemulator/gpu.nim b/tests/manyloc/gbemulator/gpu.nim
new file mode 100644
index 0000000000..1f59d79042
--- /dev/null
+++ b/tests/manyloc/gbemulator/gpu.nim
@@ -0,0 +1,110 @@
+# Part of the Nimrod Gameboy emulator.
+# Copyright (C) Dominik Picheta.
+
+import colors, strutils
+
+type
+  TGPUMode = enum
+    HBlank = 0, VBlank = 1, OAMRead = 2, VRAMRead = 3, 
+
+  TBGTile = enum
+    TileSet0, TileSet1
+  TBGMap = enum
+    TileMap0, TileMap1
+
+  TPaletteKind = enum
+    PaletteBG, PaletteObj, PaletteObj1
+
+  PGPU* = ref object
+    vram*: array[0 .. 8191, int32]
+    mode*: TGPUMode
+    clock: int32
+    line: int
+    palette: array[TPaletteKind, array[0..3, TColor]] # 4 colors. 0-1 (Lightest), 7-8 (Darkest)
+    scrollY, scrollX: int32
+    bgtilemap: TBGMap
+    bgtileset: TBGTile
+
+proc newGPU*(): PGPU =
+  new(result)
+  
+  # Set default palette
+  result.palette[PaletteBG] = [colWhite, rgb(192, 192, 192), rgb(96, 96, 96), colBlack]
+
+proc getTileAddr(gpu: PGPU, index: int32): int =
+  ## Returns the address of the beginning of the tile at ``index``.
+  case gpu.bgtileset
+  of TileSet0:
+    return 0x1000+(index*16) # Each tile is 2 bytes (16 bits)
+  of TileSet1:
+    return 0x0000+(index*16)
+
+proc getTileRow(gpu: PGPU, index: int32): array[0..7, int32] =
+  let tileAddr = getTileAddr(gpu, index)
+  let y = (gpu.line + gpu.scrollY) and 7
+  for px in 0 .. 7:
+    result[px] = gpu.vram[tileAddr+px] or (gpu.vram[tileAddr+px+1] shl 8)
+
+proc renderLine*(gpu: PGPU) =
+  echo("Render Line: ", gpu.line, " scrollX: ", gpu.scrollX, " scrollY: ", gpu.scrollY)
+  var mapOffset = if gpu.bgTileMap == TileMap0: 0x1800 else: 0x1C00
+  # Get the line of tiles to use.
+  mapOffset.inc(((gpu.line + gpu.scrollY) and 0xFF) shr 3)
+  echo("MapOffset: ", mapOffset.toHex(4))  
+  
+  let lineOffset = (gpu.scrollX shr 3) # Which tile to start with in the map line
+  
+  # Get tile index from background map
+  var tileIndex = gpu.vram[mapOffset + lineOffset]
+  
+  echo("Tile index: ", tileIndex)
+  
+  echo("bgtileset: ", gpu.bgtileset)
+
+  
+  let tile = getTileRow(gpu, tileIndex)
+
+  let y = (gpu.line + gpu.scrollY) and 7
+  let x = gpu.scrollX and 7
+  let surfaceOffset = gpu.line * 160 * 4
+
+proc next*(gpu: PGPU, time: int) =
+  gpu.clock.inc(time)
+  #echo("GPU Mode: ", gpu.mode)
+  case gpu.mode
+  of OAMRead:
+    if gpu.clock >= 80:
+      # Enter VRAMRead
+      gpu.mode = VRAMRead
+      gpu.clock = 0
+  of VRAMRead:
+    if gpu.clock >= 172:
+      # Enter HBlank
+      gpu.mode = HBlank
+      gpu.clock = 0
+      
+      # Render scanline
+      gpu.renderLine()
+  of HBlank:
+    if gpu.clock >= 204:
+      gpu.clock = 0
+      gpu.line.inc
+      #echo("HBlank line: ", gpu.line)
+      if gpu.line == 143:
+        # We reached the bottom edge of the screen (screen is 144 pixels in height.)
+        # Enter VBlank
+        gpu.mode = VBlank
+        
+        # TODO: Render surface on screen.
+      else:
+        gpu.mode = OAMRead
+  of VBlank:
+    if gpu.clock >= 456:
+      gpu.clock = 0
+      
+      # TODO: according to ref, line should be increased and, should wait
+      # for line to be greater than 153? then restart the line and mode?
+      echo("Vblank done. Line = ", gpu.line)
+      gpu.mode = OAMRead
+      gpu.line = 0
+      
\ No newline at end of file
diff --git a/tests/manyloc/gbemulator/mem.nim b/tests/manyloc/gbemulator/mem.nim
new file mode 100644
index 0000000000..953f97dfee
--- /dev/null
+++ b/tests/manyloc/gbemulator/mem.nim
@@ -0,0 +1,173 @@
+# Part of the Nimrod Gameboy emulator.
+# Copyright (C) Dominik Picheta.
+
+import os, strutils, unsigned
+import gpu
+
+type
+  PMem* = ref object
+    rom: string
+    gameName*: string
+    cartType*, romSize*, ramSize*: char
+    bios: array[0 .. 255, int32]    # 255 Bytes
+    extRAM: array[0 .. 8191, int32] # 8KB
+    workRAM: array[0 .. 8191, int32] # 8KB
+    zeroRAM: array[0 .. 127, int32]
+    gpu*: PGPU
+    
+proc hexdump(s: string) =
+  for c in s:
+    stdout.write(c.ord.BiggestInt.toHex(2) & " ")
+  echo("")
+
+const
+  NintendoGraphic =
+    [
+      '\xCE', '\xED', '\x66', '\x66', '\xCC', '\x0D', '\x00', '\x0B',
+      '\x03', '\x73', '\x00', '\x83', '\x00', '\x0C', '\x00', '\x0D',
+      '\x00', '\x08', '\x11', '\x1F', '\x88', '\x89', '\x00', '\x0E',
+      '\xDC', '\xCC', '\x6E', '\xE6', '\xDD', '\xDD', '\xD9', '\x99',
+      '\xBB', '\xBB', '\x67', '\x63', '\x6E', '\x0E', '\xEC', '\xCC',
+      '\xDD', '\xDC', '\x99', '\x9F', '\xBB', '\xB9', '\x33', '\x3E'
+    ]
+  bios = [
+    0x31'i32, 0xFE, 0xFF, 0xAF, 0x21, 0xFF, 0x9F, 0x32, 0xCB, 0x7C, 0x20, 0xFB, 0x21, 0x26, 0xFF, 0x0E,
+    0x11, 0x3E, 0x80, 0x32, 0xE2, 0x0C, 0x3E, 0xF3, 0xE2, 0x32, 0x3E, 0x77, 0x77, 0x3E, 0xFC, 0xE0,
+    0x47, 0x11, 0x04, 0x01, 0x21, 0x10, 0x80, 0x1A, 0xCD, 0x95, 0x00, 0xCD, 0x96, 0x00, 0x13, 0x7B,
+    0xFE, 0x34, 0x20, 0xF3, 0x11, 0xD8, 0x00, 0x06, 0x08, 0x1A, 0x13, 0x22, 0x23, 0x05, 0x20, 0xF9,
+    0x3E, 0x19, 0xEA, 0x10, 0x99, 0x21, 0x2F, 0x99, 0x0E, 0x0C, 0x3D, 0x28, 0x08, 0x32, 0x0D, 0x20,
+    0xF9, 0x2E, 0x0F, 0x18, 0xF3, 0x67, 0x3E, 0x64, 0x57, 0xE0, 0x42, 0x3E, 0x91, 0xE0, 0x40, 0x04,
+    0x1E, 0x02, 0x0E, 0x0C, 0xF0, 0x44, 0xFE, 0x90, 0x20, 0xFA, 0x0D, 0x20, 0xF7, 0x1D, 0x20, 0xF2,
+    0x0E, 0x13, 0x24, 0x7C, 0x1E, 0x83, 0xFE, 0x62, 0x28, 0x06, 0x1E, 0xC1, 0xFE, 0x64, 0x20, 0x06,
+    0x7B, 0xE2, 0x0C, 0x3E, 0x87, 0xF2, 0xF0, 0x42, 0x90, 0xE0, 0x42, 0x15, 0x20, 0xD2, 0x05, 0x20,
+    0x4F, 0x16, 0x20, 0x18, 0xCB, 0x4F, 0x06, 0x04, 0xC5, 0xCB, 0x11, 0x17, 0xC1, 0xCB, 0x11, 0x17,
+    0x05, 0x20, 0xF5, 0x22, 0x23, 0x22, 0x23, 0xC9, 0xCE, 0xED, 0x66, 0x66, 0xCC, 0x0D, 0x00, 0x0B,
+    0x03, 0x73, 0x00, 0x83, 0x00, 0x0C, 0x00, 0x0D, 0x00, 0x08, 0x11, 0x1F, 0x88, 0x89, 0x00, 0x0E,
+    0xDC, 0xCC, 0x6E, 0xE6, 0xDD, 0xDD, 0xD9, 0x99, 0xBB, 0xBB, 0x67, 0x63, 0x6E, 0x0E, 0xEC, 0xCC,
+    0xDD, 0xDC, 0x99, 0x9F, 0xBB, 0xB9, 0x33, 0x3E, 0x3c, 0x42, 0xB9, 0xA5, 0xB9, 0xA5, 0x42, 0x4C,
+    0x21, 0x04, 0x01, 0x11, 0xA8, 0x00, 0x1A, 0x13, 0xBE, 0x20, 0xFE, 0x23, 0x7D, 0xFE, 0x34, 0x20,
+    0xF5, 0x06, 0x19, 0x78, 0x86, 0x23, 0x05, 0x20, 0xFB, 0x86, 0x20, 0xFE, 0x3E, 0x01, 0xE0, 0x50
+  ]
+  
+proc verifyBytes[R](raw: var string, bytes: array[R, char], start: int): bool =
+  result = true
+  for i in 0 .. bytes.high:
+    if raw[i+start] != bytes[i]:
+      return false
+
+proc getBytes(raw: var string, dest: var string, slice: TSlice[int]) =
+  assert slice.a < slice.b
+  assert slice.a > 0
+  let len = slice.b - slice.a
+  dest = newString(len)
+  for i in 0 .. len:
+    dest[i] = raw[slice.a + i]
+
+proc load*(path: string): PMem =
+  new result
+  result.rom = readFile(path)
+  
+  # Verify Nintendo graphic
+  # TODO: Proper exceptions.
+  #doAssert result.rom.verifyBytes(NintendoGraphic, 0x0104)
+  
+  # Gather meta data.
+  result.gameName = result.rom[0x0134 .. 0x0142]
+  echo("Game is: " & result.gameName)
+
+  doAssert result.rom[0x0143].ord != 0x80 # 0x80 here means the ROM is for Color GB.
+  
+  result.cartType = result.rom[0x0147]
+  result.romSize  = result.rom[0x0148]
+  result.ramSize  = result.rom[0x0149]
+  result.bios = bios
+
+  result.GPU = newGPU()
+
+proc reset*(mem: PMem) =
+  for i in 0..mem.extRam.len: mem.extRam[i] = 0
+  for i in 0..mem.workRam.len: mem.workRam[i] = 0
+
+proc readByte*(mem: PMem, address: int32): int32 =
+  if (address in {0x104 .. 0x133}):
+    echo("Bios is accessing the location of the nintendo logo: ", address.toHex(4))
+  case (address and 0xF000)
+  of 0x0000:
+    # BIOS
+    if address > mem.bios.high: return 0 # TODO: Correct?
+    return mem.bios[address]
+  of 0x1000, 0x2000, 0x3000:
+    return mem.rom[address.int].ord
+  of 0x4000, 0x5000, 0x6000, 0x7000:
+    # ROM Bank 1
+  of 0x8000, 0x9000:
+    # VRAM
+    return mem.GPU.vram[address and 0x1FFF]
+  of 0xF000:
+    case address and 0x0F00
+    of 0x0F00:
+      if address > 0xFF7F:
+        return mem.zeroRAM[address and 0x007F]
+      
+      assert false
+    else:
+      assert false
+  else:
+    echo("Read ", address.toHex(4))
+    assert false
+
+proc readWord*(mem: PMem, address: int32): int32 =
+  return readByte(mem, address) or (readByte(mem, address+1) shl 8) 
+
+proc writeByte*(mem: PMem, address: int32, b: int32) =
+  case (address and 0xF000)
+  of 0x8000, 0x9000:
+    # VRAM
+    # Each pixel is 2 bits. VRAM is the tileset.
+    echo("VRAM. Address: 0x", toHex(address, 4), " Value: ", toHex(b, 4))
+    mem.GPU.vram[address and 0x1FFF] = b
+  
+  of 0xF000:
+    case address and 0x0F00
+    of 0x0F00:
+      if address > 0xFF7F:
+        #echo("ZeroRam. Address: ", toHex(address, 4), " Value: ", toHex(b, 4))
+        mem.zeroRAM[address and 0x007F] = b
+        return 
+    
+      case address
+      of 0xFF11:
+        # TODO:
+        echo("Sound Mode 1 register (0xFF11): ", b.toHex(4))
+      of 0xFF26:
+        # TODO:
+        echo("Sound on/off (0xFF26): ", b.toHex(4))
+      of 0xFF47:
+        # TODO:
+        echo("BG Palette (0xFF47): ", b.toHex(4))
+      else:
+        echo("Interrupts. Address: 0x", toHex(Address, 4), " Value: ", toHex(b, 4))
+    else:
+      echo("0xF000. Address: 0x", toHex(Address, 4), " Value: ", toHex(b, 4))
+  
+  else:
+    echo("writeByte. Address: 0x", toHex(address, 4), " Value: ", toHex(b, 4))
+
+proc writeWord*(mem: PMem, address: int32, w: int32) =
+  mem.writeByte(address, w and 255)
+  mem.writeByte(address+1, w shr 8)
+
+when isMainModule:
+  var rom = load("/home/dom/code/nimrod/gbemulator/Pokemon_Red.gb")
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
\ No newline at end of file
diff --git a/tests/manyloc/gbemulator/readme.markdown b/tests/manyloc/gbemulator/readme.markdown
new file mode 100644
index 0000000000..7961912241
--- /dev/null
+++ b/tests/manyloc/gbemulator/readme.markdown
@@ -0,0 +1,12 @@
+# gbemulator
+
+Inspired by the Rust NES emulator I have decided to write a Gameboy emulator in
+my favourite programming language.
+
+## References
+
+http://www.devrs.com/gb/files/gbspec.txt
+http://www.zilog.com/docs/z80/um0080.pdf
+https://github.com/Two9A/jsGB/blob/master/js
+https://github.com/grantgalitz/GameBoy-Online/blob/master/js/GameBoyCore.js
+http://imrannazar.com/Gameboy-Z80-Opcode-Map
\ No newline at end of file
diff --git a/tests/specials.nim b/tests/specials.nim
index b5c49ec3c0..173ebd2f80 100644
--- a/tests/specials.nim
+++ b/tests/specials.nim
@@ -178,7 +178,9 @@ proc runJsTests(r: var TResults, options: string) =
     
   for t in os.walkFiles("tests/js/t*.nim"):
     test(t)
-  for testfile in ["texceptions", "texcpt1", "texcsub", "tfinally", "tfinally2", "tfinally3", "tactiontable", "tmultim1", "tmultim3", "tmultim4"]:
+  for testfile in ["texceptions", "texcpt1", "texcsub", "tfinally",
+                   "tfinally2", "tfinally3", "tactiontable", "tmultim1",
+                   "tmultim3", "tmultim4"]:
     test "tests/run/" & testfile & ".nim"
 
 # ------------------------- register special tests here -----------------------
@@ -195,6 +197,26 @@ proc runSpecialTests(r: var TResults, options: string) =
 proc rejectSpecialTests(r: var TResults, options: string) =
   rejectThreadTests(r, options)
 
+proc findMainFile(dir: string): string =
+  # finds the file belonging to ".nimrod.cfg"; if there is no such file
+  # it returns the some ".nim" file if there is only one: 
+  const cfgExt = ".nimrod.cfg"
+  result = ""
+  var nimFiles = 0
+  for kind, file in os.walkDir(dir):
+    if kind == pcFile:
+      if file.endsWith(cfgExt): return file[.. -(cfgExt.len+1)] & ".nim"
+      elif file.endsWith(".nim"):
+        if result.len == 0: result = file
+        inc nimFiles
+  if nimFiles != 1: result.setlen(0)
+
+proc compileManyLoc(r: var TResults, options: string) =
+  for kind, dir in os.walkDir("tests/manyloc"):
+    if kind == pcDir:
+      let mainfile = findMainFile(dir)
+      compileSingleTest(r, mainfile, options)
+
 proc compileSpecialTests(r: var TResults, options: string) =
   compileRodFiles(r, options)
 
@@ -203,6 +225,8 @@ proc compileSpecialTests(r: var TResults, options: string) =
 
   compileDLLTests(r, options)
   compileDebuggerTests(r, options)
+  
+  compileManyLoc(r, options)
 
   #var given = callCompiler("nimrod i", "nimrod i", options)
   #r.addResult("nimrod i", given.msg, if given.err: reFailure else: reSuccess)
diff --git a/todo.txt b/todo.txt
index 74e6188847..0639844c87 100644
--- a/todo.txt
+++ b/todo.txt
@@ -18,6 +18,7 @@ version 0.9.2
 Bugs
 ====
 
+- docgen: sometimes effects are listed twice
 - even the easiest range checking is not performed anymore
 - 'result' is not properly cleaned for NRVO
 - instantiated generics are listed in error messages