[CC - Emulation] 6502 CPU Emulator (WIP)

--[[
  6502 By Lewisk3 (Redxone) - Special thanks to SquidDev for compiler help!
Methods of emulation:
  1. Memory segments
    : Use a table of bytes 64KB
  2. Onboard registers
    : Use a seperate table for registers
  3. Flags
    : Use a String of true or falses
  4. Data Stack
    : 256B - Stored on another memory area
--]]

-- TODO: 0200 to 0D5B = Screen memory

-- Setup _6502 Enviorment
local _NIBBLE = 4
local _BYTE = 8
local _KBYTE = 1024
local _BUSWIDTH = 16
local _CCENV = true
-- Non CC lua compatibility
if(write == nil)then write = io.write end
if(read == nil)then read = io.read end
if(sleep == nil)then sleep = function() end end
if(term == nil)then
  term = {}
  term.current = function() return { setVisible = function(tf) return false end } end
  term.isColor = function() return false end
  term.setCursorPos = function(x,y) end
  term.clear = function() end
  term.setBackgroundColor = function(col) end
  term.setTextColor = function(col) end
  colors = {}
  colors.white = 0
  os = {}
  os.pullEvent = function(ev) return nil end
  shell = {}
  shell.resolve = function(txt) return txt end
  shell.getRunningProgram = function() return "6502" end
  _CCENV = false
elseif(term.current == nil)then
  term.current().setVisible = function(tf) return false end
end
-- Monochrome support
if(not term.isColor())then
  colors.orange    = colors.white
  colors.magenta   = colors.white
  colors.lightBlue = colors.white
  colors.yellow    = colors.white
  colors.lime      = colors.white
  colors.pink      = colors.white
  colors.gray      = colors.white
  colors.lightGray = colors.white
  colors.cyan      = colors.white
  colors.purple    = colors.white
  colors.blue      = colors.white
  colors.brown     = colors.white
  colors.green     = colors.white
  colors.red       = colors.white
  colors.black     = colors.white
end
--]] "BIOS" Functionality (All functions defined for Input and Output)

-- Useful bit logic functions

  typeCheck = function(val)
      if(not tonumber(val,16))then
          return "dec"
      else
          return "hex"
      end
  end

  toHex = function(dec)
    local hex = ""
    local hexkey = "0123456789ABCDEF"
    local rim
    if(dec == 0)then hex = "0" end
    while dec > 0 do
       rim = math.floor(dec%16)
       hex = hexkey:sub(rim+1,rim+1) .. hex
       dec = math.floor(dec/16)
    end
    if(#hex == 1)then
      hex = "0" .. hex
    end
    if(dec < 0)then
      local num = 256 + dec
      return toHex(num)
    end
    return hex
  end

  toBin = function(dec)
    -- Convert to base 10 soooo easy
    local bin = ""
    local binkey = "01"
    local rim
    if(type(dec) == "string")then error("toBin -> Invalid type: " .. dec) end
    while dec > 0 do
       rim = math.floor(dec%2)
       bin = binkey:sub(rim+1,rim+1) .. bin
       dec = math.floor(dec/2)
    end
    if(#bin < 8)then
      bin = string.rep("0",8-#bin) .. bin
    end
    return bin
  end

  signedHextoDec = function(hex)
     local dechex = tonumber(hex,16)
   -- Check sign
   local checksign = toBin(dechex):sub(1,1)
   --print(toBin(dechex))
     if(checksign == "1")then
      return (dechex - 255)-1
     else
      return dechex
     end
  end

-- 1Byte Registers
function writeReg(reg,byte)
  if(not _G.ASM.reg[reg])then
    error("Invalid register -> " .. reg)
  end
  _G.ASM.reg[reg] = string.char(tonumber(byte,16))
end

function writeRegDec(reg,byte)
  if(not _G.ASM.reg[reg])then
    error("Invalid register -> " .. reg)
  end
  _G.ASM.reg[reg] = string.char(byte)
end

function writeRegChar(reg,ch)
  if(not _G.ASM.reg[reg])then
    error("Invalid register -> " .. reg)
  end
  _G.ASM.reg[reg] = ch
end

function moveRegs(from,to,flags)
  if(flags == nil)then flags = false end
  local from = readRegHex(from)
  writeReg(to,from)
  if(flags)then updateResultFlags(readRegDec(to)) end
end

function loadRegIndirect(reg,ind,itype)
  local plusx = 0
  local plusy = 0
  -- Optional indexing types
  if(itype == nil)then itype = "" end
  if(itype == "X")then
    plusx = decodeByte(readReg("X"))
  elseif(itype == "Y")then
    plusy = decodeByte(readReg("Y"))
  end

  -- Get ind data from 1, and 2 (ind + 1) and concatenate location, lsb..msb

  local ind = toHex(tonumber(ind,16) + plusx)
  local ind2 = toHex(tonumber(ind,16) + 1)
  local byte1 = readByteHex(ind)
  local byte2 = readByteHex(ind2)
  local addr = toHex(tonumber(byte2 .. byte1,16) + plusy)
  if(#addr < 4)then
    addr = string.rep("0",4-#addr) .. addr
  end
  writeReg(reg,readByteHex(addr))
end
--storeRegIndirect("A","15","X")
function storeRegIndirect(reg,ind,itype)
  local plusx = 0
  local plusy = 0
  -- Optional indexing types
  if(itype == nil)then itype = "" end
  if(itype == "X")then
    plusx = decodeByte(readReg("X"))
  end
  if(itype == "Y")then
    plusy = decodeByte(readReg("Y"))
  end
  local ind = toHex(tonumber(ind,16) + plusx)
  local ind2 = toHex(tonumber(ind,16) + 1)
  local byte1 = readByteHex(ind)
  local byte2 = readByteHex(ind2)
  local addr = toHex(tonumber(byte2 .. byte1,16) + plusy)
  if(#addr < 4)then
    addr = string.rep("0",4-#addr) .. addr
  end
  writeByte(addr,readRegHex(reg))
end

function readReg(reg)
  if(not _G.ASM.reg[reg])then
    error("Invalid register -> " .. reg)
  end
  return tostring(_G.ASM.reg[reg])
end
function readRegHex(reg)
  return toHex(decodeByte(readReg(reg)))
end
function readRegDec(reg)
  if(not _G.ASM.reg[reg])then
    error("Invalid register -> " .. reg)
  end
  return string.byte(_G.ASM.reg[reg])
end

function decodeByte(byte)
  return string.byte(byte)
end

-- Program Counter
function readPC()
  local MSB = toHex(string.byte(_G.ASM.reg['PC']:sub(1,1)))
  local LSB = toHex(string.byte(_G.ASM.reg['PC']:sub(2,2)))
  return MSB .. LSB
end

setPC = function(bytes)
  if(#bytes > 4)then print("Program counter must be 4Bytes!") end
  if(#bytes < 4)then
    bytes = string.rep("0",4-#bytes) .. bytes
  end
  local MSB = string.char(tonumber(bytes:sub(1,2),16))
  local LSB = string.char(tonumber(bytes:sub(3,4),16))
  --print(MSB .. LSB)
  _G.ASM.reg['PC'] = MSB .. LSB
end

getProgramByte = function(byte)
  -- Program byte will be a hex value
    local hexPC = toHex(string.byte(readReg('PC')))
    -- PROGM is in ASCII format
    -- Convert to HEX then return
    return readByteHex(hexPC)
end

movePC = function(bytes)
  local absval = toHex(tonumber(readPC(),16) + bytes)
  if(#absval < 4)then absval = "0" .. absval end
  setPC(absval)
end

-- Stacks

function pushStack(val)
  local sp = toHex(string.byte(readReg('SP')))
  local pointer = toHex(string.byte(readReg("SP")))
  local val = tonumber(val,16)
  local offs = math.floor(tonumber(pointer,16)%_BUSWIDTH)
  local pointer = math.floor(tonumber(pointer,16)/_BUSWIDTH)+1
  local byte = _G.ASM.stack[pointer]
  byte = byte:sub(1,offs-1) .. string.char(val) .. byte:sub(offs+1,#byte)
  _G.ASM.stack[pointer] = byte
  -- Move pointer to next item in stack
  pointer = tonumber(sp,16) - 1
  -- If the pointer reached the end of the stack, reset it
  if(pointer < 1)then
    pointer = "FF"
    -- Write pointer back into Stack Pointer
    writeReg("SP",pointer)
  else
    -- Write pointer back into Stack Pointer
    writeRegDec("SP",pointer)
  end
end


function pullStack()
  -- Pull value off stack, and increment the stack pointer
  local sp = toHex(string.byte(readReg("SP")))
  local pointer = toHex(string.byte(readReg("SP"))+1)
  local offs = math.floor(tonumber(pointer,16)%_BUSWIDTH)
  local pointer = math.floor(tonumber(pointer,16)/_BUSWIDTH)+1
  local byte = _G.ASM.stack[pointer]
  -- Move pointer to next item in stack
  pointer = tonumber(sp,16) + 1
  -- If the pointer reached the end of the stack, reset it
  if(pointer > 255)then
    pointer = "00"
    -- Write pointer back into Stack Pointer
    writeReg("SP",pointer)
  else
    -- Write pointer back into Stack Pointer
    writeRegDec("SP",pointer)
  end
  if(byte == nil)then
    return string.char("0")
  end
  return byte:sub(offs,offs)
end

-- Flags

function setFlag(flagbit,onoff)
  if(_G.ASM.flagtypes[flagbit])then flagbit = _G.ASM.flagtypes[flagbit] end
  flagbit = tostring(flagbit)
  local flags = toBin(decodeByte(_G.ASM.flags))
  if(onoff ~= 1 and onoff ~= 0)then error("Invaild flag state!") end
  if(#flags < 0 or #flags > 8)then error("Invalid flag index!") end
  flags = flags:sub(1,flagbit-1) .. tostring(onoff) .. flags:sub(flagbit+1,#flags)
  _G.ASM.flags = string.char(tonumber(flags,2))
end
function getFlag(flagbit)
  if(_G.ASM.flagtypes[flagbit])then flagbit = _G.ASM.flagtypes[flagbit] end
  return toBin(decodeByte(_G.ASM.flags)):sub(flagbit,flagbit)
end
function getFlagsByte()
  return _G.ASM.flags
end
function setAllFlags(flaghex)
  _G.ASM.flags = string.char(decodeByte(flaghex))
end

function updateResultFlags(val)
  -- Val is in Hex
  if(type(val) == "string")then
      val = tonumber(val,16)
  end
  local binval = toBin(val)
  local flags = toBin(decodeByte(_G.ASM.flags))
  if(val == 0)then
    setFlag("ZRO",1)
  else
    setFlag("ZRO",0)
  end
  if(binval:sub(1,1) == "1")then
    setFlag("NEG",1)
  else
    setFlag("NEG",0)
  end
  return
end

function checkCarry(mode,val)
  if(type(val) == "string")then error("Value must be decimal for CARRY check!") end
  if(string.lower(mode) == "add")then
    if(val > 255)then
      setFlag("CRY",1)
      return true
    elseif(val < 0)then
      setFlag("CRY",1)
      return true
    else
      setFlag("CRY",0)
      return false
    end
  elseif(string.lower(mode) == "sub")then
    if(val < 0)then
      setFlag("CRY",0)
      return true
    else
      setFlag("CRY",1)
      return false
    end
  else
    error("Invalid CARRY check mode: " .. mode)
  end
end

function addHex(n1,n2)
  local num = tonumber(n1,16) + tonumber(n2,16)
  if(num > 255)then
    num = num - 256
  end
  return toHex(num)
end
function subHex(n1,n2)
  local num = (tonumber(n1,16) - tonumber(n2,16))
  if(num < 0)then
    num = 256 + num
  end
  return toHex(num)
end

function addSignedDec(n1,n2)
  local num = tonumber(n1,16) + tonumber(n2,16)
  if(num > 255)then
    num = num - 256
  end
  return num
end

function subSignedDec(n1,n2)
  local num = (tonumber(n1,16) - tonumber(n2,16))
  if(num < 0)then
    num = 256 + num
  end
  return num
end





function checkOverflow(mode,val,val2)
  if(val2 == nil)then val2 = "00" end
  if(string.lower(mode) == "bit")then
    val = toBin(tonumber(val,16))
    -- Check bit 6 (0 indexed) of value for a 1 if so, set V flag
    if(val:sub(2,2) == "1")then
      setFlag("OVR",1)
      return true
    else
      setFlag("OVR",0)
      return false
    end
  elseif(string.lower(mode) == "math")then
    val = signedHextoDec(val) + signedHextoDec(tonumber(val2,16))
    -- Check if value is negative (2s signed)
    -- Convert value into Decimal
    -- Convert decimal into 8bit signed decimal
    -- Check if val is outside the bounds of an 8bit
    -- 2's complement signed number, if so, set overflow.
    if(val < -127)then
      setFlag("OVR",1)
      return true
    elseif(val > 127)then
      setFlag("OVR",1)
      return true
    else
      setFlag("OVR",0)
      return false
    end
  end
end

function getSign(val)
  -- Returns true if negative
  return toBin(tonumber(val,16)):sub(1,1) == "1"
end

function signedAdd(val,val2)
  if(getFlag("DEC") == "1")then
    return signedAddDec(val, val2)
  end
  local snum = toHex(signedHextoDec(val) + signedHextoDec(val2))
  local num = tonumber(val,16) + tonumber(val2,16)
  checkOverflow("math",snum)
  checkCarry("add",num)
  if(getFlag("CRY") == "1")then
    -- Push off MSB from NUM, to fit in 1Byte space
    num = toHex(num)
    num = num:sub(#num-1,#num)
    num = tonumber(num,16)
  end
  return toHex(num)
end

function signedAddDec(val, val2)
    -- Determine string HEX or Dec, based on DEC flag "reasonableness" (Basically, the DEC flag math can still do hex, but only to an extent. )
    if(tonumber(val) == nil)then val = tonumber(val,16) else val = tonumber(val) end
    if(tonumber(val2) == nil)then val2 = tonumber(val2,16) else val2 = tonumber(val2) end
  local num = val + val2
    if(num > 99)then
      setFlag("CRY",1)
      num = ( (num-1) - 99 )
    elseif(num < 0)then
      setFlag("CRY",1)
    else
      setFlag("CRY",0)
    end
  num = tostring(num)
  if(#num == 1)then num = "0" .. num end
  return num
end

--signedSub("FF","01")
function signedSub(val,val2)
  if(getFlag("DEC") == "1")then
    return signedSubDec(val, val2)
  end
  local snum = toHex(signedHextoDec(val) - (signedHextoDec(val2)) )
  local num = tonumber(val,16) - (tonumber(val2,16))
  checkOverflow("math",snum)
  checkCarry("sub",num)
  return toHex(num)
end

function signedSubDec(val, val2)
    -- Determine string HEX or Dec, based on DEC flag "reasonableness" (Basically, the DEC flag math can still do hex, but only to an extent. )
    if(tonumber(val) == nil)then val = tonumber(val,16) else val = tonumber(val) end
    if(tonumber(val2) == nil)then val2 = tonumber(val2,16) else val2 = tonumber(val2) end
  local num = val - val2
    if(num < 0)then
      setFlag("CRY",1)
      num = ( 99 + num )
    else
      setFlag("CRY",0)
    end
    num = tostring(num)
    if(#num == 1)then num = "0" .. num end
  return num
end

-- RAM
function readIndirectByte(ind,itype)
  local plusx = 0
  local plusy = 0
  if(itype == "X")then
    plusx = decodeByte(readReg("X"))
  end
  if(itype == "Y")then
    plusy = decodeByte(readReg("Y"))
  end
  local ind = toHex(tonumber(ind,16) + plusx)
  local ind2 = toHex(tonumber(ind,16) + 1)
  local byte1 = readByteHex(ind)
  local byte2 = readByteHex(ind2)
  local addr = toHex(tonumber(byte2 .. byte1,16) + plusy)
  return addr
end

function writeByte(loc,byte,debug)
  if(debug == nil)then debug = false end
  local locraw = loc
  local offs = math.floor(tonumber(loc,16)%_BUSWIDTH)+1
  local absoluteloc = tonumber(loc,16) - math.floor(tonumber(loc,16)%_BUSWIDTH)
  local loc  = math.floor(tonumber(loc,16)/_BUSWIDTH)+1
  local byte = string.char(tonumber(byte,16))
  local byteloc = _G.ASM.ram[loc]
  if(debug)then print(absoluteloc .. ":" .. offs .. " = " .. byte) end
  byteloc = byteloc:sub(1,offs-1) .. byte .. byteloc:sub(offs+1,#byteloc)
  _G.ASM.ram[loc] = byteloc
  refreshScreen(locraw)
  if(debug)then print(absoluteloc .. " = " .. byteloc) end
end
function writeByteDec(loc,byte,debug)
  if(debug == nil)then debug = false end
  local locraw = loc
  local offs = math.floor(tonumber(loc,16)%_BUSWIDTH)+1
  local absoluteloc = tonumber(loc,16) - math.floor(tonumber(loc,16)%_BUSWIDTH)
  local loc  = math.floor(tonumber(loc,16)/_BUSWIDTH)+1
  local byte = string.char(byte)
  local byteloc = _G.ASM.ram[loc]
  if(debug)then print(absoluteloc .. ":" .. offs .. " = " .. byte) end
  byteloc = byteloc:sub(1,offs-1) .. byte .. byteloc:sub(offs+1,#byteloc)
  _G.ASM.ram[loc] = byteloc
  refreshScreen(locraw)
  if(debug)then print(absoluteloc .. " = " .. byteloc) end
end
function writeDecByte(loc,byte,debug)
  if(debug == nil)then debug = false end
  local locraw = loc
  local offs = math.floor(loc%_BUSWIDTH)+1
  local absoluteloc = loc - math.floor(loc%_BUSWIDTH)
  local loc  = math.floor(loc/_BUSWIDTH)+1
  local byte = string.char(byte)
  local byteloc = _G.ASM.ram[loc]
  if(debug)then print(absoluteloc .. ":" .. offs .. " = " .. byte) end
  byteloc = byteloc:sub(1,offs-1) .. byte .. byteloc:sub(offs+1,#byteloc)
  _G.ASM.ram[loc] = byteloc
  refreshScreen(locraw)
  if(debug)then print(absoluteloc .. " = " .. byteloc) end
end
function readByte(loc,debug)
  if(debug == nil)then debug = false end
  local offs =  math.floor(tonumber(loc,16)%_BUSWIDTH)+1
  local loc  = math.floor(tonumber(loc,16)/_BUSWIDTH)+1
  local byte = tostring(_G.ASM.ram[loc]:sub(offs,offs))
  if(debug)then print(loc .. ":" .. offs .. " = " .. byte) end
  return byte
end
function readAddressByte(byte,itype)
  local reg = false
  if(byte == "A" or byte == "X" or byte == "Y")then
    reg = true
  end
  if(itype == nil)then itype = "" end
  local plus = 0
  if(itype == "X")then
    plus = decodeByte(readReg("X"))
  end
  if(itype == "Y")then
    plus = decodeByte(readReg("Y"))
  end
  local addr = 0
  local val = 0
  if(not reg)then addr = toHex(tonumber(byte,16) + plus) end
  if(reg)then
    val = toHex(decodeByte(readReg(reg)))
  else
    val = toHex(decodeByte(readByte(addr)))
  end
  return val
end


function readByteHex(loc,debug)
  return toHex(string.byte(readByte(loc,debug)))
end
function readByteDec(loc,debug)
  return toHex(string.byte(readByte(loc,debug)))
end

function readDecByte(decloc)
  return string.byte(readByte(loc,debug))
end

function writeChar(loc,byte,debug)
  if(debug == nil)then debug = false end
  local locraw = loc
  local offs = math.floor(tonumber(loc,16)%_BUSWIDTH)+1
  local absoluteloc = tonumber(loc,16) - math.floor(tonumber(loc,16)%_BUSWIDTH)
  local loc  = math.floor(tonumber(loc,16)/_BUSWIDTH)+1
  local byteloc = _G.ASM.ram[loc]
  if(debug)then print(absoluteloc .. ":" .. offs .. " = " .. byte) end
  byteloc = byteloc:sub(1,offs-1) .. byte .. byteloc:sub(offs+1,#byteloc)
  _G.ASM.ram[loc] = byteloc
  refreshScreen(locraw)
  if(debug)then print(absoluteloc .. " = " .. byteloc) end
end


-- Screen memory/rendering
  function valueCheck(val)
    if(type(val) == "string")then val = tonumber(val,16) end
    return val
  end


function refreshScreen(mem)
  local scr_start = 512
  local scr_end   = 2448
  if( _G.ASM.pmode == 2 )then
    mem = (valueCheck(mem))
    if(mem >= scr_start and mem <= scr_end)then
      drawScreenAt(toHex(mem))
    end
  end
end


function drawScreenAt(addr,debug)
    if( _G.ASM.pmode ~= 2)then return nil end
    if(debug == nil)then debug = false end
    local scr_start = tonumber("0200",16)
    local scr_width = 51
    local scr_end   = tonumber("0990",16)
    local addr = tonumber(addr,16)
    local iscolor = false
    local ischar  = false
    if(addr < scr_start or addr > scr_end)then
        return nil
    end
    -- Determine screen type at memory
    if(addr%2 == 0)then
        iscolor = true
    else
        ischar  = true
    end
    -- Decode cursor position
    -- As Address is always larger then or equal to screen start
    local ypos = math.floor(((addr - scr_start)/2)/scr_width)+1
    local xpos = 0
    if(ischar)then
        xpos = math.ceil(((addr - scr_start)/2)-((ypos-1)*51))
    elseif(iscolor)then
        xpos = math.ceil((((addr+1) - scr_start)/2)-((ypos-1)*51))
    end
    if(debug)then
        print("Color: " .. tostring(iscolor))
        print("Text : " .. tostring(ischar))
        print("X: " .. xpos)
        print("Y: " .. ypos)
    end
    -- Decode colors
    local colors = "FF"
    local tcol = colors.black
    local bcol = colors.black
    if(iscolor)then
        colors = readByteHex(toHex(addr))
    elseif(ischar)then
        colors = readByteHex(toHex(addr-1))
    end
    -- Seperatew colors get MSB, LSB
    tcol = 2^tonumber(colors:sub(1,1),16)
    bcol = 2^tonumber(colors:sub(2,2),16)
    if(debug)then
        print("Text color: " .. tcol)
        print("Back color: " .. bcol)
    end
    -- Print char
    local char = " "
    if(ischar)then
        char = readByte(toHex(addr))
    elseif(iscolor)then
        char = readByte(toHex(addr+1))
    end
    local ox, oy = term.getCursorPos()
    term.setCursorPos(xpos, ypos)
    term.setTextColor(tcol)
    term.setBackgroundColor(bcol)
    write(char)
    term.setTextColor(1)
    term.setBackgroundColor(2^15)
    term.setCursorPos(ox, oy)
end

function drawScreen()
    if( _G.ASM.pmode ~= 2)then return nil end
    local size = 969
    local scr_start = tonumber("0200",16)
    local scr_end   = tonumber("0990",16)
    for i = 0, size*2 do
        drawScreenAt(toHex(scr_start+(i+1)))
    end
end

-- Instruction decoding
function runOpperation(op,type,val,debug,noexe)
  -- Get Hex code first
  local diss = ""
  if(op == nil)then return false end
  if(debug == nil)then debug = false end -- OCD precaution :P
  if(noexe == nil)then noexe = false end -- OCD precaution :P
  if(_G.ASM._HEXENCODE[op] == nil)then error("Invalid instruction: " .. op) end
  if(_G.ASM._HEXENCODE[op][type] == nil)then error("Invalid type for: " .. op .. ", " .. type) end
  -- Seperate arguments into Bytes
  local opEncode = _G.ASM._HEXENCODE[op][type]
  -- Split into bytes of 2
  local bytes = {}
  val = tostring(val)
  if(#val > 2)then
      for i=1, #val, 2 do
          bytes[#bytes+1] = val:sub(i,i+1)
      end
  else
    bytes[1] = val
  end
    -- If bytes passed is more than isntruction requires, error
    local optimalBytes = _G.ASM._OPCODES[opEncode].bytes
    if(optimalBytes > 0)then
      --if(#bytes > optimalBytes)then error("Malformed instruction: " .. op .. ", " .. val) end
      local i, j = 1, #bytes
    while i < j do
      bytes[i], bytes[j] = bytes[j], bytes[i]
      i = i + 1
      j = j - 1
    end
      for k, v in pairs(bytes) do
        -- For Accumulative instructions
        if(#v == 1)then v = "FF FF" end
        diss = diss .. v .. " "
      end
    end
    if(debug)then print("Dissassembly: " .. opEncode .. " " .. diss) end
  if(not noexe)then
    return opEncode .. " " .. diss, _G.ASM._OPCODES[opEncode]:exe(unpack(bytes))
  else
    return opEncode .. " " .. diss
  end
end
function procInstructionType(op,debug,err)
  -- Get instruction
  -- Syntax Tabing check
  if(err == nil)then err = true end
  if(#op:gsub("%s+","") == 0)then
    return nil
  elseif(op:sub(1,1) == " " or op:sub(1,1) == "\t")then
    op = op:gsub("%s+","")
    op = op:sub(1,3) .. " " .. op:sub(4,#op)
  end
  if(debug == nil)then debug = false end -- OCD precaution :P
  local instruction = string.upper(op:sub(1,3))
  local args = (op:sub(5,#op)):gsub("%s+","")
  local optype = "undefined"
  -- Check for implicit instructions
  if((#args:gsub('%s+','') == 0 or args == nil or args == "") and #op:gsub("%s+","") == 3)then
    optype = "IMP"
    if(debug)then print(instruction .. ":" .. optype) end
    return instruction, optype, ""
  end
  -- Check for Accumulator instructions
  if(#args == 1)then
    args = string.upper(args)
    if(args == "A" or args == "X" or args == "Y")then
      if(args == "A")then num = "01" end
      if(args == "X")then num = "02" end
      if(args == "Y")then num = "03" end
      optype = "ACC"
      if(debug)then print(instruction .. ":" .. optype .. " ->" .. args) end
      return instruction, optype, num
    else
      if(err)then error("Syntax Error: " .. op) else return "err" end
    end
  end
  -- Check if Relative
  if(args:sub(1,1) == "*")then
    args = args:gsub("%s+","")
    local sign = args:sub(2,#args):sub(1,1)
    local num = signedHextoDec(args:sub(3,#args))
    if(num > 127)then error("Out of bounds Error: " .. op) end
    if(num < -127)then error("Out of bounds Error: " .. op) end
    if(num == nil)then error("Syntax Error: " .. op) end
    if(sign == "-")then
      num = toHex(tonumber("FF",16) - (tonumber(toHex(math.abs(num)-1),16)))
    else
      num = toHex(num)
    end
    optype = "REL"
    if(debug)then print(instruction .. ":" .. optype .. " -> " .. num) end
    return instruction, optype, num
  end
  -- Check if Alpha numeric
  if(args:sub(1,1) == "#" and args:sub(2,2) == "'" )then
    if(args:sub(4,4) ~= "'")then if(err)then error("Syntax Error: " .. op) else return "err" end end
    local char = args:sub(3,3)
    local num = toHex(string.byte(char))
    args = args:sub(1,1) .. "$" .. num
  end
  -- Determine type of instruction
  -- Check if not HEX, then convert
  if(args:sub(1,1) == "#" and args:sub(2,2) ~= "$")then
    local num = args:sub(2,#args)
    -- If trying to zero page x or y a decimal, error
    if(args:find(","))then
      if(err)then error("Syntax Error: " .. op) else return "err" end
    end
    -- Convert num to hex
    num = toHex(tonumber(num))
    args = args:sub(1,1) .. "$" .. num
  end
  -- Check if value is an Immeditate address
  if(args:sub(1,1) == "#")then
    local num = args:sub(3,#args)
    if(#num == 2)then -- Instruction is Immeditate
      optype = "IMM"
      if(debug)then print(instruction .. ":" .. optype .. " -> " .. num) end
      return instruction, optype, num
    else
      if(err)then error("Syntax Error: " .. op) else return "err" end
    end
  end
  -- Zero Page X, Absolute XY checking
  if(args:sub(1,1) == "$")then
    local num = args:sub(2,#args)
    -- Check for , because a Zero Page X can pass as an Absolute numerically wise.
    if(not num:find(","))then
      if(tonumber(num,16) == nil)then error("Syntax Error: " .. op) end
      if(#num == 2)then -- Instruction is Zero Page
        optype = "ZP"
        if(debug)then print(instruction .. ":" .. optype .. " -> " .. num) end
        return instruction, optype, num
      end
      if(#num == 4)then -- Instruction is absolute
        optype = "AB"
        if(debug)then print(instruction .. ":" .. optype .. " -> " .. num) end
        return instruction, optype, num
      end
    end
    -- Check for Zero Paged X
    if(num:find(","))then
      local nargs = {}
      -- Take spaces out of string, then split it into 2 variables
      local num = num:gsub("%s+", "")
      -- Split string by comma
      for word in string.gmatch(num, '([^,]+)') do
          table.insert(nargs, word)
      end
      num = nargs[1]
      local reg = string.upper(nargs[2])
      -- If we have more than 2 variables in the string, then the user has seriously screwed up,
      -- Be sure to annoy them with a noice syntax error.
      if(#nargs > 2)then if(err)then error("Syntax Error: " .. op) else return "err" end end
      -- Check if num is zero paged or absolute
      if(#num == 2)then
        -- Looks like we got a Zero Page, check for registered versions
        if(string.upper(reg) == "X")then
          optype = "ZPX"
          if(debug)then print(instruction .. ":" .. optype .. " -> " .. num) end
          return instruction, optype, num
        elseif(string.upper(reg) == "Y")then
          optype = "ZPY"
          if(debug)then print(instruction .. ":" .. optype .. " -> " .. num) end
          return instruction, optype, num
        end
      end

      if(#num == 4)then
        -- Looks like we got a Absolute, check for registered versions
        if(string.upper(reg) == "X")then
          optype = "ABX"
          if(debug)then print(instruction .. ":" .. optype .. " -> " .. num .. ", X") end
          return instruction, optype, num
        elseif(string.upper(reg) == "Y")then
          optype = "ABY"
          if(debug)then print(instruction .. ":" .. optype .. " -> " .. num .. ", Y") end
          return instruction, optype, num
        else
          -- Invalid register
          if(err)then error("Syntax Error: " .. op) else return "err" end
        end
      end
    else
      -- Wut, we got a more than 4 digit value with no registers attached to it?!?!?, wut u smoking boi!
      if(err)then error("Syntax Error: " .. op) else return "err" end
    end
  end

  -- Indirect checking
  if(args:sub(1,1) == "(")then
    -- Any multi-argument statement needs to be space checked!
    local args = string.upper(args:gsub("%s+", ""))
    local num = 0
    -- Insert true hex number into indirect instruction
    if(args:sub(2,2) ~= "$")then
      num = tonumber(args:sub(3,4))
      if(num == nil)then if(err)then error("Syntax Error: " .. op) else return "err" end end
      num = toHex(num)
      args = args:sub(1,1) .. "$" .. num .. args:sub(4,#args)
    elseif(args:sub(2,2) == "#")then
      -- If user is trying to pass a value as an address, NOPE 'em!
      if(err)then error("Syntax Error: " .. op) else return "err" end
    else
      -- If hex number is passed by default set that minus its $ symbol
      num = args:sub(3,4)
    end
    if(args:sub(5,7) == "),Y")then
      -- If this is found at 5 we know, this must be a INY
      optype = "INY"
      if(debug)then print(instruction .. ":" .. optype .. " -> (" .. num .. "), Y") end
      return instruction, optype, num
    end
    if(args:sub(5,7) == ",X)")then
      -- If this is found at 7 we know, this must be a INX
      optype = "INX"
      if(debug)then print(instruction .. ":" .. optype .. " -> (" .. num .. ", X)") end
      return instruction, optype, num
    end
    if(args:sub(7,7) == ")")then
      if(args:sub(2,2) ~= "$")then if(err)then error("Syntax Error: " .. op) else return "err" end end
      -- If this is found at 7 we know, this must be a IN
      -- Get new number as 2Byte HEX
      num = args:sub(3,6)
      if(#num == 4)then
        optype = "IN"
      else
        if(err)then error("Syntax Error: " .. op) else return "err" end
      end

      if(debug)then print(instruction .. ":" .. optype .. " -> (" .. num .. ")") end
      return instruction, optype, num
    end
    -- Zero paged indirect
    if(args:sub(5,5) == ")")then
      if(args:sub(2,2) ~= "$")then if(err)then error("Syntax Error: " .. op) else return "err" end end
      -- If this is found at 5 we know, this must be a IZP
      -- Get new number as 2Byte HEX
      num = args:sub(3,4)
      if(#num == 2)then
        optype = "IZP"
      else
        if(err)then error("Syntax Error: " .. op) else return "err" end
      end
      if(debug)then print(instruction .. ":" .. optype .. " -> (" .. num .. ")") end
      return instruction, optype, num
    end
  end

  if(optype == "undefined")then
    if(err)then error("Syntax Error: " .. op) else return "err" end
  end

end


--- Setting everything up

function initalize()
  -- Define sizes in Bytes
  _G.ASM = {}
  _G.ASM.MSIZE = _KBYTE*64
  _G.ASM.SSIZE = _BYTE*32
  local GRAM = {}
  local GREG = {}
  local GSTACK = {}
  -- Initialize Virtual RAM
  for _RINDEX = 1, _G.ASM.MSIZE/_BUSWIDTH do
      GRAM[_RINDEX] = string.rep(string.char("0"),_BUSWIDTH)
  end
  -- Initialize Virtual STACK
  for _SINDEX = 1, _G.ASM.SSIZE/_BUSWIDTH do
      GSTACK[_SINDEX] = string.rep(string.char("0"),_BUSWIDTH)
  end
  -- Initialize Virtual Registers
  GREG['A'] = string.char("0")
  GREG['X'] = string.char("0")
  GREG['Y'] = string.char("0")
  GREG['SP'] = string.char(tonumber("FF",16))
  GREG['PC'] = string.char(tonumber("06",16)) .. string.char(tonumber("00",16))

  _G.ASM.pmode = 1 -- Program execution mode, 1 = text, 2 = graphics
  _G.ASM.ram = GRAM
  _G.ASM.stack = GSTACK
  _G.ASM.reg = GREG
  _G.ASM.flags = string.char(tonumber("00100000",2))
  _G.ASM.flagtypes = {
    ["CRY"] = 8, -- Carry
    ["ZRO"] = 7, -- Zero Flag
    ["INT"] = 6, -- Interupt Disable
    ["DEC"] = 5, -- Decimal
    ["BRK"] = 4, -- Software interupt
    ["UNK"] = 3, -- Unknown, logical 1
    ["OVR"] = 2, -- Overflow
    ["NEG"] = 1, -- Sign
  }
  -- Instruction encoding
  _G.ASM._HEXENCODE = {
    ['LDA'] = {
      ['IZP'] = "B2",
      ['IMM'] = "A9",
      ['ZP']  = "A5",
      ['ZPX'] = "B5",
      ['AB']  = "AD",
      ['ABX'] = "BD",
      ['ABY'] = "B9",
      ['INX'] = "A1",
      ['INY'] = "B1",
    },
    ['STA'] = {
      ['IZP'] = "92",
      ['ZP']  = "85",
      ['ZPX'] = "95",
      ['AB']  = "8D",
      ['ABX'] = "9D",
      ['ABY'] = "99",
      ['INX'] = "81",
      ['INY'] = "91",
    },
    ['ADC'] = {
      ['IZP'] = "72",
      ['IMM'] = "69",
      ['ZP']  = "65",
      ['ZPX'] = "75",
      ['AB']  = "6D",
      ['ABX'] = "7D",
      ['ABY'] = "79",
      ['INX'] = "61",
      ['INY'] = "71",
    },
    ['AND'] = {
      ['IZP'] = "32",
      ['IMM'] = "29",
      ['ZP']  = "25",
      ['ZPX'] = "35",
      ['AB']  = "2D",
      ['ABX'] = "3D",
      ['ABY'] = "39",
      ['INX'] = "21",
      ['INY'] = "31",
    },
    ['ASL'] = {
      ['ACC'] = "0A",
      ['ZP']  = "06",
      ['ZPX'] = "16",
      ['AB']  = "0E",
      ['ABX'] = "1E",
    },
    ['BCC'] = {
      ['REL'] = "90",
    },
    ['BCS'] = {
      ['REL'] = "B0",
    },
    ['BEQ'] = {
      ['REL'] = "F0",
    },
    ['BIT'] = {
      ['ZP']  = "24",
      ['AB']  = "2C",
    },
    ['BMI'] = {
      ['REL'] = "30",
    },
    ['BNE'] = {
      ['REL'] = "D0",
    },
    ['BPL'] = {
      ['REL'] = "10",
    },
    ['BRK'] = {
      ['IMP'] = "00",
    },
    ['BVC'] = {
      ['REL'] = "50",
    },
    ['BVS'] = {
      ['REL'] = "70",
    },
    ['CLC'] = {
      ['IMP'] = "18",
    },
    ['CLD'] = {
      ['IMP'] = "D8",
    },
    ['CLI'] = {
      ['IMP'] = "58",
    },
    ['CLV'] = {
      ['IMP'] = "B8",
    },
    ['CMP'] = {
      ['IZP'] = "D2",
      ['IMM'] = "C9",
      ['ZP']  = "C5",
      ['ZPX'] = "D5",
      ['AB']  = "CD",
      ['ABX'] = "DD",
      ['ABY'] = "D9",
      ['INX'] = "C1",
      ['INY'] = "D1",
    },
    ['CPX'] = {
      ['IMM'] = "E0",
      ['ZP']  = "E4",
      ['AB']  = "EC",
    },
    ['CPY'] = {
      ['IMM'] = "C0",
      ['ZP']  = "C4",
      ['AB']  = "CC",
    },
    ['DEC'] = {
      ['ACC'] = "3A",
      ['ZP']  = "C6",
      ['ZPX'] = "D6",
      ['AB']  = "CE",
      ['ABX'] = "DE",
    },
    ['DEX'] = {
      ['IMP'] = "CA",
    },
    ['DEY'] = {
      ['IMP'] = "88",
    },
    ['EOR'] = {
      ['IZP'] = "52",
      ['IMM'] = "49",
      ['ZP']  = "45",
      ['ZPX'] = "55",
      ['AB']  = "4D",
      ['ABX'] = "5D",
      ['ABY'] = "59",
      ['INX'] = "41",
      ['INY'] = "51",
    },
    ['INC'] = {
      ['ACC'] = "1A",
      ['ZP']  = "E6",
      ['ZPX'] = "F6",
      ['AB']  = "EE",
      ['ABX'] = "FE",
    },
    ['INX'] = {
      ['IMP'] = "E8",
    },
    ['INY'] = {
      ['IMP'] = "C8",
    },
    ['JMP'] = {
      ['AB']  = "4C",
      ['IN']  = "6C",
    },
    ['JSR'] = {
      ['AB'] = "20",
    },
    ['LDX'] = {
      ['IMM'] = "A2",
      ['ZP']  = "A6",
      ['ZPY'] = "B6",
      ['AB']  = "AE",
      ['ABY'] = "BE",
    },
    ['LDY'] = {
      ['IMM'] = "A0",
      ['ZP']  = "A4",
      ['ZPX'] = "B4",
      ['AB']  = "AC",
      ['ABX'] = "BC",
    },
    ['LSR'] = {
      ['ACC'] = "4A",
      ['ZP']  = "46",
      ['ZPX'] = "56",
      ['AB']  = "4E",
      ['ABX'] = "5E",
    },
    ['NOP'] = {
      ['IMP'] = "EA",
    },
    ['ORA'] = {
      ['IZP'] = "12",
      ['IMM'] = "09",
      ['ZP']  = "05",
      ['ZPX'] = "15",
      ['AB']  = "0D",
      ['ABX'] = "1D",
      ['ABY'] = "19",
      ['INX'] = "01",
      ['INY'] = "11",
    },
    ['PHA'] = {
      ['IMP'] = "48",
    },
    ['PHP'] = {
      ['IMP'] = "08",
    },
    ['PLA'] = {
      ['IMP'] = "68",
    },
    ['PLP'] = {
      ['IMP'] = "28",
    },
    ['ROL'] = {
      ['ACC'] = "2A",
      ['ZP']  = "26",
      ['ZPX'] = "36",
      ['AB']  = "2E",
      ['ABX'] = "3E",
    },
    ['ROR'] = {
      ['ACC'] = "6A",
      ['ZP']  = "66",
      ['ZPX'] = "76",
      ['AB']  = "6E",
      ['ABX'] = "7E",
    },
    ['RTI'] = {
      ['IMP'] = "40",
    },
    ['RTS'] = {
      ['IMP'] = "60",
    },
    ['SBC'] = {
      ['IZP'] = "F2",
      ['IMM'] = "E9",
      ['ZP']  = "E5",
      ['ZPX'] = "F5",
      ['AB']  = "ED",
      ['ABX'] = "FD",
      ['ABY'] = "F9",
      ['INX'] = "E1",
      ['INY'] = "F1",
    },
    ['SEC'] = {
      ['IMP'] = "38",
    },
    ['SED'] = {
      ['IMP'] = "F8",
    },
    ['SEI'] = {
      ['IMP'] = "78",
    },
    ['STX'] = {
      ['ZP']  = "86",
      ['ZPY'] = "96",
      ['AB']  = "8E",
    },
    ['STY'] = {
      ['ZP']  = "84",
      ['ZPX'] = "94",
      ['AB']  = "8C",
    },
    ['TAX'] = {
      ['IMP'] = "AA",
    },
    ['TAY'] = {
      ['IMP'] = "A8",
    },
    ['TSX'] = {
      ['IMP'] = "BA",
    },
    ['TXA'] = {
      ['IMP'] = "8A",
    },
    ['TXS'] = {
      ['IMP'] = "9A",
    },
    ['TYA'] = {
      ['IMP'] = "98",
    },
  }
  _G.ASM._OPCODES = {
  -- Bytes = How many more bytes to read
    -- Assembler will convert values to hex
    -- TODO: REMINDER!!!
    -- ACCUMULATIVE INSTRUCTIONS: Use 01 = A, 02 = X, 03 = Y
    --]] LDA instructions
    ["B2"] = {bytes=1,exe=function(self,val)
       -- Zero paged Indirect
      loadRegIndirect("A",val)
      updateResultFlags(readRegDec("A"))
    end},-- LDA ($00)
    ['A9'] = {bytes=1,exe=function(self,val)
      -- Load a value into A
      writeReg("A",val)
      updateResultFlags(val)
    end}, -- LDA #00
    ['A5'] = {bytes=1,exe=function(self,mem)
      -- Load a value from memory into A
      writeReg("A",readByteHex(mem))
      updateResultFlags(readByteDec(mem))
    end}, -- LDA $00
    ['B5'] = {bytes=1,exe=function(self,val)
      local val =  ( tonumber(val,16) + decodeByte(readReg("X")) )
      writeReg("A",readDecByte(val))
      updateResultFlags(val)
    end}, -- LDA $00, X
    ['AD'] = {bytes=2,exe=function(self,lsb,msb)
      local val = readByteHex(msb .. lsb)
      writeReg('A',val)
      updateResultFlags(val)
    end}, -- LDA $0000
    ['BD'] = {bytes=2,exe=function(self,lsb,msb)
      local val = readAddressByte(msb..lsb,"X")
      writeReg('A', val)
      updateResultFlags(val)
    end}, -- LDA $0000, X
    ['B9'] = {bytes=2,exe=function(self,lsb,msb)
      local val = readAddressByte(msb..lsb,"Y")
      writeReg('A',val)
      updateResultFlags(val)
    end}, -- LDA $0000, Y
    ['A1'] = {bytes=1,exe=function(self,val)
      loadRegIndirect("A",val,"X")
      updateResultFlags(decodeByte(readReg("A")))
    end}, -- LDA ($00, X)
    ['B1'] = {bytes=1,exe=function(self,val)
      loadRegIndirect("A",val,"Y")
      updateResultFlags(decodeByte(readReg("A")))
    end}, -- LDA ($00), Y
  --]] STA instructions
    ['92'] = {bytes=1,exe=function(self,val)
      storeRegIndirect("A",val)
    end}, -- STA ($00)
    ['85'] = {bytes=1,exe=function(self,val) writeByteDec(val,readRegDec("A")) end}, -- STA $00
    ['95'] = {bytes=1,exe=function(self,val)
      local val = (tonumber(val,16) + decodeByte(readReg("X")))
      writeDecByte(val,readRegDec("A"))
    end}, -- STA $00, X
    ['8D'] = {bytes=2,exe=function(self,lsb,msb) writeByteDec(msb .. lsb,readRegDec("A")) end}, -- STA $0000
    ['9D'] = {bytes=2,exe=function(self,lsb,msb)
      local val = msb .. lsb
      local val = (tonumber(val,16) + decodeByte(readReg("X")))
      writeDecByte(val,readRegDec("A"))
    end}, -- STA $0000, X
    ['99'] = {bytes=2,exe=function(self,lsb,msb)
      local val = msb .. lsb
      local val = (tonumber(val,16) + decodeByte(readReg("Y")))
      writeDecByte(val,readRegDec("A"))
    end}, -- STA $0000, Y
    ['81'] = {bytes=1,exe=function(self,val)
      storeRegIndirect("A",val,"X")
     end}, -- STA ($00, X)
    ['91'] = {bytes=1,exe=function(self,val)
      storeRegIndirect("A",val,"Y")
    end}, -- STA ($00), Y
  -- ADC (Add with carry) Adds to A
    ['72'] = {bytes=1,exe=function(self,val)
      local num = signedAdd(readRegHex("A"),readByteHex(readIndirectByte(val)))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end}, -- ADC ($00)
    ['69'] = {bytes=1,exe=function(self,val)
      local num = signedAdd(readRegHex("A"), val)
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- ADC #00
    ['65'] = {bytes=1,exe=function(self,val)
      local num = signedAdd(readRegHex("A"), readByteHex(val) )
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- ADC $00
    ['75'] = {bytes=1,exe=function(self,val)
      local num = signedAdd(readRegHex("A"),readAddressByte(val,"X"))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- ADC $00, X
    ['6D'] = {bytes=2,exe=function(self,lsb,msb)
      local num = signedAdd(readRegHex("A"), readByteHex(msb..lsb))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- ADC $0000
    ['7D'] = {bytes=2,exe=function(self,lsb,msb)
      local num = signedAdd(readRegHex("A"),readAddressByte(msb..lsb,"X"))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- ADC $0000, X
    ['79'] = {bytes=2,exe=function(self,lsb,msb)
      local num = signedAdd(readRegHex("A"),readAddressByte(msb..lsb,"Y"))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- ADC $0000, Y
    ['61'] = {bytes=1,exe=function(self,val)
      local num = signedAdd(readRegHex("A"),readByteHex(readIndirectByte(val,"X")))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- ADC ($00, X)
    ['71'] = {bytes=1,exe=function(self,val)
      local num = signedAdd(readRegHex("A"),readByteHex(readIndirectByte(val,"Y")))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- ADC ($00), Y
  -- AND  (Logical And)
    ['32'] = {bytes=1,exe=function(self,val)
       local num = bit.band(decodeByte(readReg("A")), tonumber( readByteHex(readIndirectByte(val)), 16) )
       updateResultFlags(num)
       writeRegDec("A",num)
    end}, -- AND ($00)
    ['29'] = {bytes=1,exe=function(self,val)
       local num = bit.band(decodeByte(readReg("A")), tonumber(val,16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- AND #00
    ['25'] = {bytes=1,exe=function(self,val)
      local num = bit.band(decodeByte(readReg("A")), decodeByte(readByte(val)))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- AND $00
    ['35'] = {bytes=1,exe=function(self,val)
       local num = bit.band(decodeByte(readReg("A")), tonumber(readAddressByte(val,"X"),16) )
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- AND $00, X
    ['2D'] = {bytes=2,exe=function(self,lsb,msb)
      local num = bit.band(decodeByte(readReg("A")), decodeByte(readByte(msb..lsb)))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- AND $0000
    ['3D'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.band(decodeByte(readReg("A")), tonumber(readAddressByte(msb..lsb,"X"),16) )
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- AND $0000, X
    ['39'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.band(decodeByte(readReg("A")), tonumber(readAddressByte(msb..lsb,"Y"),16) )
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- AND $0000, Y
    ['21'] = {bytes=1,exe=function(self,val)
       local num = bit.band(decodeByte(readReg("A")), tonumber( readByteHex(readIndirectByte(val,"X")), 16) )
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- AND ($00, X)
    ['31'] = {bytes=1,exe=function(self,val)
       local num = bit.band(decodeByte(readReg("A")), tonumber( readByteHex(readIndirectByte(val,"Y"))),16)
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- AND ($00), Y
  -- ASL  (Arithmetic Shift Left)
    ['0A'] = {bytes=1,exe=function(self,val)
       if(val == "01")then val = "A" end
       if(val == "02")then val = "X" end
       if(val == "03")then val = "Y" end
       local num = bit.blshift(decodeByte(readReg(val)), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags(num)
       if(num > 255)then num = 255 setFlag("NEG",0) end
       writeRegDec(val,num)
    end},-- ASL A/X/Y
    ['06'] = {bytes=1,exe=function(self,val)
       local num = bit.blshift(decodeByte(readByte(val)), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = 255 setFlag("NEG",0) end
       writeByteDec(val,num)
    end},-- ASL $00
    ['16'] = {bytes=1,exe=function(self,val)
       local num = bit.blshift(tonumber(readAddressByte(val,"X"),16), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = 255 setFlag("NEG",0) end
       writeByteDec(addHex(val,readRegHex("X")),num)
    end},-- ADC $00, X
    ['0E'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.blshift(decodeByte(readByte(msb..lsb)), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = 255 setFlag("NEG",0) end
       writeByteDec(msb..lsb,num)
    end},-- ADC $0000
    ['1E'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.blshift(tonumber(readAddressByte(msb..lsb,"X"),16), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = 255 setFlag("NEG",0) end
       writeByteDec(addHex(msb..lsb,readRegHex("Y")),num)
    end},-- ADC $0000, X
  -- BCC   (Branch if Carry Clear)
    ['90'] = {bytes=1,exe=function(self,val)
      local num = signedHextoDec(val)
      if(getFlag("CRY") == "0")then movePC(num) end
    end},-- BCC *+val
  -- BCS   (Branch if Carry Set)
    ['B0'] = {bytes=1,exe=function(self,val)
      local num = signedHextoDec(val)
      if(getFlag("CRY") == "1")then movePC(num) end
    end},-- BCS *+val
  -- BEQ   (Branch if Equal)
    ['F0'] = {bytes=1,exe=function(self,val)
      local num = signedHextoDec(val)
      if(getFlag("ZRO") == "1")then movePC(num) end
    end},-- BCS *+val
  -- BIT  (Bit Test)
    ['24'] = {bytes=1,exe=function(self,val)
      local num = bit.band(decodeByte(readReg("A")), decodeByte(readByte(val)))
      if(toBin(num):sub(2,2))then setFlag("OVR",1) end
      updateResultFlags(num)
    end},-- BIT $00
    ['2C'] = {bytes=2,exe=function(self,val)
    end},-- BIT $0000
  -- BMI  (Branch if Minus)
    ['30'] = {bytes=1,exe=function(self,val)
      local num = signedHextoDec(val)
      if(getFlag("NEG") == "1")then movePC(num) end
    end},-- BMI *+val
  -- BNE  (Branch if Not Equal)
    ['D0'] = {bytes=1,exe=function(self,val)
      local num = signedHextoDec(val)

      if(getFlag("ZRO") == "0")then movePC(num) end
    end},-- BNE *+val
  -- BPL  (Branch if Positive)
    ['10'] = {bytes=1,exe=function(self,val)
      local num = signedHextoDec(val)
      if(getFlag("NEG") == "0")then movePC(num) end
    end},-- BPL *+val
  -- BRK  (Force Interrupt)
    ['00'] = {bytes=0,exe=function(self)
      pushStack(toHex(decodeByte(getFlagsByte())))
      local pc = "0" .. tostring(tonumber(readPC(),16)+1)
      pushStack(tostring(readPC()):sub(1,2))
      pushStack(tostring(readPC()):sub(3,4))
      -- Push status to stack, stop program wait for re-run program executor will check for interupt flag and pull from stacks and resume program
      setFlag("BRK",1)
    end},-- BRK
  -- BVC  (Branch if Overflow Clear)
    ['50'] = {bytes=1,exe=function(self,val)
      local num = signedHextoDec(val)
      if(getFlag("OVR") == "0")then movePC(num) end
    end},-- BVC *+val
  -- BVS  (Branch if Overflow Set)
    ['70'] = {bytes=1,exe=function(self,val)
      local num = signedHextoDec(val)
      if(getFlag("OVR") == "1")then movePC(num) end
    end},-- BVC *+val
  -- CLC  (Clear Carry Flag)
    ['18'] = {bytes=0,exe=function(self,val)
      setFlag("CRY",0)
    end},-- CLC
  -- CLD  (Clear Decimal Mode)
    ['D8'] = {bytes=0,exe=function(self,val)
      setFlag("DEC",0)
    end},-- CLD
  -- CLI  (Clear Interrupt Disable)
    ['58'] = {bytes=0,exe=function(self,val)
      setFlag("INT",0)
    end},-- CLI
  -- CLV  (Clear Overflow Flag)
    ['B8'] = {bytes=0,exe=function(self,val)
      setFlag("OVR",0)
    end},-- CLV
  -- CMP  (Compare)
    ['D2'] = {bytes=1,exe=function(self,val)
        local num = tonumber(readByteHex(readIndirectByte(val)),16) - decodeByte(readReg("A"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end}, -- CMP ($00)
    ['C9'] = {bytes=1,exe=function(self,val)
        local num = decodeByte(readReg("A")) - tonumber(val,16)
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CMP #00
    ['C5'] = {bytes=1,exe=function(self,val)
        local num = decodeByte(readByte(val)) - decodeByte(readReg("A"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CMP $00
    ['D5'] = {bytes=1,exe=function(self,val)
        local num = tonumber(readAddressByte(val,"X"),16) - decodeByte(readReg("A"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CMP $00, X
    ['CD'] = {bytes=2,exe=function(self,lsb,msb)
        local num = decodeByte(readByte(msb..lsb)) - decodeByte(readReg("A"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CMP $0000
    ['DD'] = {bytes=2,exe=function(self,lsb,msb)
        local num = tonumber(readAddressByte(msb..lsb,"X"),16) - decodeByte(readReg("A"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CMP $0000, X
    ['D9'] = {bytes=2,exe=function(self,lsb,msb)
        local num = tonumber(readAddressByte(msb..lsb,"Y"),16) - decodeByte(readReg("A"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CMP $0000, Y
    ['C1'] = {bytes=1,exe=function(self,val)
        local num = tonumber(readByteHex(readIndirectByte(val,"X")),16) - decodeByte(readReg("A"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CMP ($00, X)
    ['D1'] = {bytes=1,exe=function(self,val)
        local num = tonumber(readByteHex(readIndirectByte(val,"Y")),16) - decodeByte(readReg("A"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CMP ($00), Y
  -- CPX  (Compare X Register)
    ['E0'] = {bytes=1,exe=function(self,val)
        local num = tonumber(val,16) - decodeByte(readReg("X"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CPX #00
    ['E4'] = {bytes=1,exe=function(self,val)
        local num = decodeByte(readByte(val)) - decodeByte(readReg("X"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CPX $00
    ['EC'] = {bytes=2,exe=function(self,lsb,msb)
        local num = decodeByte(readByte(msb..lsb)) - decodeByte(readReg("X"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CPX $0000
  -- CPY  (Compare Y Register)
    ['C0'] = {bytes=1,exe=function(self,val)
        local num = tonumber(val,16) - decodeByte(readReg("Y"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CPY #00
    ['C4'] = {bytes=1,exe=function(self,val)
        local num = decodeByte(readByte(val)) - decodeByte(readReg("Y"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CPY $00
    ['CC'] = {bytes=2,exe=function(self,lsb,msb)
        local num = decodeByte(readByte(msb..lsb)) - decodeByte(readReg("Y"))
        if(num >= 0)then setFlag("CRY",1) else setFlag("CRY",0) end -- If A >= M
        updateResultFlags(num)
    end},-- CPY $0000
  -- DEC  (Decrement Memory)
    ['3A'] = {bytes=1,exe=function(self,val)
      if(val == "01")then val = "A" end
      if(val == "02")then val = "X" end
      if(val == "03")then val = "Y" end
      local num = subHex(readRegHex(val),"01")
      writeReg(val,num)
    end}, -- INC A/X/Y
    ['C6'] = {bytes=1,exe=function(self,val)
      local num = subSignedDec(readByteHex(val),"01")
      writeByteDec(val,num)
    end},-- DEC $00
    ['D6'] = {bytes=1,exe=function(self,val)
      local num = subSignedDec(readAddressByte(val,"X"),"01")
      writeByteDec(addHex(val,readRegHex("X")),num)
    end},-- DEC $00, X
    ['CE'] = {bytes=2,exe=function(self,lsb,msb)
      local num = subSignedDec(readByteHex(msb..lsb),"01")
      writeByteDec(msb..lsb,num)
    end},-- DEC $0000
    ['DE'] = {bytes=2,exe=function(self,lsb,msb)
      local num = subSignedDec(readAddressByte(msb..lsb,"X"),"01")
      writeByteDec(addHex(msb..lsb,readRegHex("X")),num)
    end},-- DEC $0000, X
  -- DEX  (Decrement X Register)
    ['CA'] = {bytes=0,exe=function(self,val)
      local num = subSignedDec(readRegHex('X'),"01")
      updateResultFlags(num)
      writeRegDec("X",num)
    end},-- DEX
  -- DEY  (Decrement Y Register)
    ['88'] = {bytes=0,exe=function(self,val)
      local num = subSignedDec(readRegHex('Y'),"01")
      updateResultFlags(num)
      writeRegDec("Y",num)
    end},-- DEY
  -- EOR   (Exclusive OR)
    ['52'] = {bytes=1,exe=function(self,val)
       local num = bit.bxor(tonumber(readRegHex("A"),16), tonumber(readByteHex(readIndirectByte(val)),16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end}, -- EOR ($00)
    ['49'] = {bytes=1,exe=function(self,val)
       local num = bit.bxor(tonumber(readRegHex("A"),16), tonumber(val,16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- EOR #00
    ['45'] = {bytes=1,exe=function(self,val)
       local num = bit.bxor(tonumber(readRegHex("A"),16), tonumber(readByteHex(val),16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- EOR $00
    ['55'] = {bytes=1,exe=function(self,val)
       local num = bit.bxor(tonumber(readRegHex("A"),16), tonumber(readAddressByte(val,"X"),16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- EOR $00, X
    ['4D'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.bxor(tonumber(readRegHex("A"),16), tonumber(readByteHex(msb..lsb),16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- EOR $0000
    ['5D'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.bxor(tonumber(readRegHex("A"),16), tonumber(readAddressByte(msb..lsb,"X"),16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- EOR $0000, X
    ['59'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.bxor(tonumber(readRegHex("A"),16), tonumber(readAddressByte(msb..lsb,"Y"),16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- EOR $0000, Y
    ['41'] = {bytes=1,exe=function(self,val)
       local num = bit.bxor(tonumber(readRegHex("A"),16), tonumber(readByteHex(readIndirectByte(val,"X")),16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- EOR ($00, X)
    ['51'] = {bytes=1,exe=function(self,val)
       local num = bit.bxor(tonumber(readRegHex("A"),16), tonumber(readByteHex(readIndirectByte(val,"Y")),16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end},-- EOR ($00), Y
  -- INC  (Increment Memory)
    ['1A'] = {bytes=1,exe=function(self,val)
      if(val == "01")then val = "A" end
      if(val == "02")then val = "X" end
      if(val == "03")then val = "Y" end
      local num = addHex(readRegHex(val),"01")
      writeReg(val,num)
    end}, -- INC A/X/Y
    ['E6'] = {bytes=1,exe=function(self,val)
      local num = addSignedDec(readByteHex(val),"01")
      writeByteDec(val,num)
    end},-- INC $00
    ['F6'] = {bytes=1,exe=function(self,val)
      local num = addSignedDec(readAddressByte(val,"X"),"01")
      writeByteDec(addHex(val,readRegHex("X")),num)
    end},-- INC $00, X
    ['EE'] = {bytes=2,exe=function(self,lsb,msb)
      local num = addSignedDec(readByteHex(msb..lsb),"01")
      writeByteDec(msb..lsb,num)
    end},-- INC $0000
    ['FE'] = {bytes=2,exe=function(self,val)
      local num = addSignedDec(readAddressByte(msb..lsb,"X"),"01")
      writeByteDec(addHex(msb..lsb,readRegHex("X")),num)
    end},-- INC $0000, X
  -- INX  (Increment X Register)
    ['E8'] = {bytes=0,exe=function(self,val)
      local num = addSignedDec(readRegHex('X'),"01")
      updateResultFlags(num)
      writeRegDec("X",num)
    end},-- INX
  -- INY  (Increment Y Register)
    ['C8'] = {bytes=0,exe=function(self,val)
      local num = addSignedDec(readRegHex('Y'),"01")
      updateResultFlags(num)
      writeRegDec("Y",num)
    end},-- INY
  -- JMP  (Jump)
    ['4C'] = {bytes=2,exe=function(self,lsb,msb)
      setPC(msb..lsb)
    end},-- JMP $0000
    ['6C'] = {bytes=2,exe=function(self,lsb,msb)
      setPC(readIndirectByte(msb..lsb))
    end},-- JMP ($0000)
  -- JSR
    ['20'] = {bytes=2,exe=function(self,lsb,msb)
      pushStack(readPC():sub(1,2))
      pushStack(readPC():sub(3,4))
      setPC(msb..lsb)
    end},-- JSR $0000
  -- LDX  (Load X Register)
    ['A2'] = {bytes=1,exe=function(self,val)
      writeReg("X",val)
      updateResultFlags(val)
    end},-- LDX #00
    ['A6'] = {bytes=1,exe=function(self,val)
      writeReg("X",readByteHex(val))
      updateResultFlags(readByteDec(val))
    end},-- LDX $00
    ['B6'] = {bytes=1,exe=function(self,val)
      local val =  ( tonumber(val,16) + decodeByte(readReg("Y")) )
      writeRegDec("X",val)
      updateResultFlags(val)
    end},-- LDX $00, Y
    ['AE'] = {bytes=2,exe=function(self,lsb,msb)
      local val = readByteHex(msb .. lsb)
      writeRegDec('X',val)
      updateResultFlags(val)
    end},-- LDX $0000
    ['BE'] = {bytes=2,exe=function(self,lsb,msb)
      local val = readAddressByte(msb..lsb,"Y")
      writeReg('X', val)
      updateResultFlags(val)
    end},-- LDX $0000, Y
  -- LDY  (Load Y Register)
    ['A0'] = {bytes=1,exe=function(self,val)
      writeReg("Y",val)
      updateResultFlags(val)
    end},-- LDY #00
    ['A4'] = {bytes=1,exe=function(self,val)
      writeReg("Y",readByteHex(val))
      updateResultFlags(readByteDec(val))
    end},-- LDY $00
    ['B4'] = {bytes=1,exe=function(self,val)
      local val =  ( tonumber(val,16) + decodeByte(readReg("X")) )
      writeRegDec("Y",val)
      updateResultFlags(val)
    end},-- LDY $00, X
    ['AC'] = {bytes=2,exe=function(self,lsb,msb)
      local val = readByteHex(msb .. lsb)
      writeReg('Y',val)
      updateResultFlags(val)
    end},-- LDY $0000
    ['BC'] = {bytes=2,exe=function(self,lsb,msb)
      local val = readAddressByte(msb..lsb,"X")
      writeReg('Y', val)
      updateResultFlags(val)
    end},-- LDY $0000, X
  -- LSR  (Logical Shift Right)
    ['4A'] = {bytes=1,exe=function(self,val)
         if(val == "01")then val = "A" end
       if(val == "02")then val = "X" end
       if(val == "03")then val = "Y" end
       local num = bit.brshift(decodeByte(readReg(val)), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags(num)
       writeRegDec(val,num)
    end},-- LSR A/X/Y
    ['46'] = {bytes=1,exe=function(self,val)
       local num = bit.brshift(decodeByte(readByte(val)), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags(num)
       writeByteDec(val,num)
    end},-- LSR $00
    ['56'] = {bytes=1,exe=function(self,val)
       local num = bit.brshift(tonumber(readAddressByte(val,"X"),16), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags(num)
       writeByteDec(val,num)
    end},-- LSR $00, X
    ['4E'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.brshift(decodeByte(readByte(msb..lsb)), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags(num)
       writeByteDec(msb..lsb,num)
    end},-- LSR $0000
    ['5E'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.brshift(tonumber(readAddressByte(msb..lsb,"X"),16), 1)
       setFlag("CRY",tonumber(toBin(num):sub(8,8)))
       updateResultFlags(num)
       writeByteDec(msb..lsb,num)
    end},-- LSR $0000, X
  -- NOP (No Operation)
    ['EA'] = {bytes=0,exe=function(self,val)
      sleep(0) -- CC is alot faster than ur average 6502
    end},-- NOP
  -- ORA (Logical Inclusive OR)
    ['12'] = {bytes=1,exe=function(self,val)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(readByteHex(readIndirectByte(val)),16))
       updateResultFlags(num)
       writeRegDec("A",num)
    end}, -- ORA ($00)
    ['09'] = {bytes=1,exe=function(self,val)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(val,16))
       updateResultFlags((num))
       writeRegDec("A",(num))
    end},-- ORA #00
    ['05'] = {bytes=1,exe=function(self,val)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(readByteHex(val),16))
       updateResultFlags((num))
       writeRegDec("A",(num))
    end},-- ORA $00
    ['15'] = {bytes=1,exe=function(self,val)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(readAddressByte(val,"X"),16))
       updateResultFlags((num))
       writeRegDec("A",(num))
    end},-- ORA $00, X
    ['0D'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(readByteHex(msb..lsb),16))
       updateResultFlags((num))
       writeRegDec("A",(num))
    end},-- ORA $0000
    ['1D'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(readAddressByte(msb..lsb,"X"),16))
       updateResultFlags((num))
       writeRegDec("A",(num))
    end},-- ORA $0000, X
    ['19'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(readAddressByte(msb..lsb,"Y"),16))
       updateResultFlags((num))
       writeRegDec("A",(num))
    end},-- ORA $0000, Y
    ['01'] = {bytes=1,exe=function(self,val)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(readByteHex(readIndirectByte(val,"X")),16))
       updateResultFlags((num))
       writeRegDec("A",(num))
    end},-- ORA ($00, X)
    ['11'] = {bytes=1,exe=function(self,val)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(readByteHex(readIndirectByte(val,"Y")),16))
       updateResultFlags((num))
       writeRegDec("A",(num))
    end},-- ORA ($00), Y
  -- PHA (Push Accumulator)
    ['48'] = {bytes=0,exe=function(self,val)
      pushStack(readRegHex("A"))
    end},-- PHA
  -- PHP (Push Processor Status)
    ['08'] = {bytes=0,exe=function(self,val)
      pushStack(toHex(decodeByte(getFlagsByte())))
    end},-- PHP
  -- PLA (Pull Accumulator)
    ['68'] = {bytes=0,exe=function(self,val)
      writeRegDec("A", decodeByte(pullStack()))
      updateResultFlags(readRegDec("A"))
    end},-- PLA
  -- PLP (Pull Processor Status)
    ['28'] = {bytes=0,exe=function(self,val)
      setAllFlags(pullStack())
    end},-- PLP
  -- ROL (Rotate Left)
    ['2A'] = {bytes=1,exe=function(self,val)
       if(val == "01")then val = "A" end
       if(val == "02")then val = "X" end
       if(val == "03")then val = "Y" end
       setFlag("CRY",tonumber(toBin(decodeByte(readReg(val))):sub(8,8)))
       local num = bit.blshift(decodeByte(readReg(val)), 1)
       updateResultFlags(num)
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeRegDec(val,num)
    end},-- ROL A/X/Y
    ['26'] = {bytes=1,exe=function(self,val)
       local num = bit.blshift(decodeByte(readByte(val)), 1)
       setFlag("CRY",tonumber(toBin(decodeByte(readByte(val))):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeByteDec(val,(num))
    end},-- ROL $00
    ['36'] = {bytes=1,exe=function(self,val)
       local num = bit.blshift(tonumber(readAddressByte(val,"X"),16), 1)
       setFlag("CRY",tonumber(toBin(tonumber(readAddressByte(val,"X"),16)):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeByteDec(readAddressByte(val,"X"),(num))
    end},-- ROL $00, X
    ['2E'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.blshift(decodeByte(readByte(msb..lsb)), 1)
       setFlag("CRY",tonumber(toBin(decodeByte(readByte(msb..lsb))):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeByteDec(msb..lsb,(num))
    end},-- ROL $0000
    ['3E'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.blshift(tonumber(readAddressByte(msb..lsb,"X"),16), 1)
       setFlag("CRY",tonumber(toBin(tonumber(readAddressByte(msb..lsb,"X"),16)):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeByteDec(readAddressByte(msb..lsb,"X"),(num))
    end},-- ROL $0000, X
  -- ROR (Rotate Right)
    ['6A'] = {bytes=1,exe=function(self,val)
       if(val == "01")then val = "A" end
       if(val == "02")then val = "X" end
       if(val == "03")then val = "Y" end
       setFlag("CRY",tonumber(toBin(decodeByte(readReg(val))):sub(8,8)))
       local num = bit.brshift(decodeByte(readReg(val)), 1)
       updateResultFlags((num))
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeRegDec(val,(num))
    end},-- ROR A/X/Y
    ['66'] = {bytes=1,exe=function(self,val)
       local num = bit.brshift(decodeByte(readByte(val)), 1)
       setFlag("CRY",tonumber(toBin(decodeByte(readByte(val))):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeByteDec(val,(num))
    end},-- ROR $00
    ['76'] = {bytes=1,exe=function(self,val)
       local num = bit.brshift(tonumber(readAddressByte(val,"X"),16), 1)
       setFlag("CRY",tonumber(toBin(tonumber(readAddressByte(val,"X"),16)):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeByteDec(readAddressByte(val,"X"),(num))
    end},-- ROR $00, X
    ['6E'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.brshift(decodeByte(readByte(msb..lsb)), 1)
       setFlag("CRY",tonumber(toBin(decodeByte(readByte(msb..lsb))):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeByteDec(msb..lsb,(num))
    end},-- ROR $0000
    ['7E'] = {bytes=2,exe=function(self,lsb,msb)
       local num = bit.brshift(tonumber(readAddressByte(msb..lsb,"X"),16), 1)
       setFlag("CRY",tonumber(toBin(tonumber(readAddressByte(msb..lsb,"X"),16)):sub(8,8)))
       updateResultFlags((num))
       if(num > 255)then num = tonumber(toHex(num):sub(#toHex(num)-1,#toHex(num)),16) end
       writeByteDec(readAddressByte(msb..lsb,"X"),(num))
    end},-- ROR $0000, X
  -- RTI (Return from Interrupt)
    ['40'] = {bytes=0,exe=function(self,val)
      local lsb = toHex(decodeByte(pullStack()))
      local msb = toHex(decodeByte(pullStack()))
      local status = pullStack()
      setAllFlags(status)
      setPC(msb..lsb)
    end},-- RTI
  -- RTS (Return from Subroutine)
    ['60'] = {bytes=0,exe=function(self,val)
      local lsb =  toHex(decodeByte(pullStack()))
      local msb =  toHex(decodeByte(pullStack()))
      setPC(msb..lsb)
    end},-- RTS
  -- SBC (Subtract with Carry)
    ['F2'] = {bytes=1,exe=function(self,val)
       local num = bit.bor(tonumber(readRegHex("A"),16), tonumber(readByteHex(readIndirectByte(val)),16))
       updateResultFlags((num))
       writeRegDec("A",(num))
    end}, -- SBC ($00)
    ['E9'] = {bytes=1,exe=function(self,val)
      local num = signedSub(readRegHex("A"), val)
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- SBC #00
    ['E5'] = {bytes=1,exe=function(self,val)
      local num = signedSub(readRegHex("A"), readByteHex(val) )
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- SBC $00
    ['F5'] = {bytes=1,exe=function(self,val)
      local num = signedSub(readRegHex("A"),readAddressByte(val,"X"))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- SBC $00, X
    ['ED'] = {bytes=2,exe=function(self,lsb,msb)
      local num = signedSub(readRegHex("A"), readByteHex(msb..lsb))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- SBC $0000
    ['FD'] = {bytes=2,exe=function(self,lsb,msb)
      local num = signedSub(readRegHex("A"),readAddressByte(msb..lsb,"X"))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- SBC $0000, X
    ['F9'] = {bytes=2,exe=function(self,lsb,msb)
      local num = signedSub(readRegHex("A"),readAddressByte(msb..lsb,"Y"))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- SBC $0000, Y
    ['E1'] = {bytes=2,exe=function(self,val)
      local num = signedSub(readRegHex("A"),readByteHex(readIndirectByte(val,"X")))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- SBC ($00, X)
    ['F1'] = {bytes=2,exe=function(self,val)
      local num = signedSub(readRegHex("A"),readByteHex(readIndirectByte(val,"Y")))
      writeReg("A",num)
      updateResultFlags(decodeByte(readReg("A")))
    end},-- SBC ($00), Y
  -- SEC (Set Carry Flag)
    ['38'] = {bytes=0,exe=function(self,val)
      setFlag("CRY",1)
    end},-- SEC
  -- SED (Set Decimal Flag)
    ['F8'] = {bytes=0,exe=function(self,val)
      setFlag("DEC",1)
    end},-- SED
  -- SEI (Set Interrupt Disable)
    ['78'] = {bytes=0,exe=function(self,val)
      setFlag("INT",1)
    end},-- SEI
  -- STX (Store X Register)
    ['86'] = {bytes=1,exe=function(self,val)
      writeByte(val,readRegHex("X"))
    end},-- STX $00
    ['96'] = {bytes=1,exe=function(self,val)
      local val = toHex(tonumber(val,16) + decodeByte(readReg("Y")))
      writeByteDec(addHex(val,readRegHex("Y")),decodeByte(readReg("X")))
    end},-- STX $00, Y
    ['8E'] = {bytes=2,exe=function(self,lsb,msb)
      writeByte(msb .. lsb,readRegHex("X"))
    end},-- STX $0000
  -- STY (Store Y Register)
    ['84'] = {bytes=1,exe=function(self,val)
      writeByte(val,readRegHex("Y"))
    end},-- STY $00
    ['94'] = {bytes=1,exe=function(self,val)
      local val = toHex(tonumber(val,16) + decodeByte(readReg("X")))
      writeByteDec(addHex(val,readRegHex("X"),decodeByte(readReg("Y"))))
    end},-- STY $00, X
    ['8C'] = {bytes=2,exe=function(self,lsb,msb)
      writeByte(msb .. lsb,readRegHex("Y"))
    end},-- STY $0000
  -- TAX (Transfer Accumulator to X)
    ['AA'] = {bytes=0,exe=function(self,val)
        moveRegs("A","X",true)
    end},-- TAX
  -- TAY (Transfer Accumulator to Y)
    ['A8'] = {bytes=0,exe=function(self,val)
        moveRegs("A","Y",true)
    end},-- TAX
  -- TSX (Transfer Stack Pointer to X)
    ['BA'] = {bytes=1,exe=function(self,val)
        moveRegs("SP`","X",true)
    end},-- TSX
  -- TXA (Transfer X to Accumulator)
    ['8A'] = {bytes=0,exe=function(self,val)
        moveRegs("X","A",true)
    end},-- TXA
  -- TXS (Transfer X to Stack Pointer)
    ['9A'] = {bytes=0,exe=function(self,val)
        moveRegs("X","SP",true)
    end},-- TXS
  -- TYA (Transfer Y to Accumulator)
    ['98'] = {bytes=0,exe=function(self,val)
        moveRegs("Y","A",true)
    end},-- TYA
}
end

function getInstuctionBytes(op,type)
  if(_G.ASM._HEXENCODE[op])then
    if(_G.ASM._OPCODES[_G.ASM._HEXENCODE[op][type]] == nil)then
      print(type)
    end
    return _G.ASM._OPCODES[_G.ASM._HEXENCODE[op][type]].bytes+1
  else
    return "err"
  end
end

function str_shearWord(str,word)
  local str = str:gsub("%s+","")
  return str:sub(#word+1,#str)
end

function AssembleHEX(code,ln)
  local op, otype, num = procInstructionType(code,false,false)
  if(op == "err")then error("Syntax error line " .. ln .. ": " .. code:gsub("%s+","")) end
  local hex = runOpperation(op,otype,num,false,true)
  return hex
end

function DecodeOpCodeHex(hex,args)
    for k, v in pairs(_G.ASM._HEXENCODE) do
        for kk, vv in pairs(v) do
            if(vv == hex)then
                local format = k .. " "
                if(kk == "IMP")then
                elseif(kk == "IMM")then
                    format = format .. "#$" .. args[1]
                elseif(kk == "AB")then
                    format = format .. "$" .. args[2] .. args[1]
                elseif(kk == "ABX")then
                    format = format .. "$" .. args[2] .. args[1] .. ", X"
                elseif(kk == "ABY")then
                    format = format .. "$" .. args[2] .. args[1] .. ", Y"
                elseif(kk == "IN")then
                    format = format .. "($" .. args[1] .. ")"
                elseif(kk == "INX")then
                    format = format .. "($" .. args[1] .. ", X)"
                elseif(kk == "INY")then
                    format = format .. "($" .. args[1] .. "), Y"
                elseif(kk == "ACC")then
                    format = format .. "$" .. args[1]
                elseif(kk == "REL")then
                    format = format .. "$" .. args[1]
                elseif(kk == "ZP")then
                    format = format .. "$" .. args[1]
                end
                return format
            end
        end
    end
end

function disassembleASM(input)
    local code = ""
    local hex = {}
    local f = fs.open(input,"rb")
    local progstart = ""
    local counter = 1
    local index = 1
      for byte in f.read do -- Iterate over every byte in the file.
         if(index > 2)then
             hex[#hex+1] = toHex(byte)
         else
            progstart = progstart .. toHex(byte)
         end
         index = index + 1
      end
      f.close()

      print("Read " .. index .. " Bytes.")
      local codeindex = 1
    while codeindex < #hex do
        local args = {}
        local dump = hex[codeindex]
        local opBytes = 0
        local opperation = "???"
        if(_G.ASM._OPCODES[hex[codeindex]] ~= nil)then
            opBytes = _G.ASM._OPCODES[hex[codeindex]].bytes
            if(opBytes >= 1)then
                for byteIndex = 1, opBytes do
                    args[#args+1] = hex[codeindex+byteIndex]
                    dump = dump .. " " .. hex[codeindex+byteIndex]
                end
            end
            opperation = DecodeOpCodeHex(hex[codeindex],args)
        end
        -- Example:
        -- Address  Hexdump    Disassembly
        -- -------------------------------
        -- $600     A9 02 03    LDA $0302
        -- $601     A9 02       LDA $02
        -- ..............................
        local addr = toHex(tonumber(progstart,16) + codeindex-1)

        code = code .. "\n" .. "$" .. string.rep("0",4-#addr) .. addr .. "    " .. dump .. string.rep(" ",(8-#dump)+4) .. opperation
        codeindex = codeindex + 1
        codeindex = codeindex + opBytes
    end
    return code
end

function runCompiledASM(input,mode,debug)
  local step = true
  if(mode == "-s")then step = true else step = false end
  if(debug == nil)then debug = true end
  if(not fs.exists(input))then error("File doesnt exist: " .. input) end
  -- Convert Bytes to hex
  local dump = ""
  local hex = {}
  local f = fs.open(input,"rb")
  local progstart = ""
  local index = 1
  for byte in f.read do -- Iterate over every byte in the file.
     if(index > 2)then
         hex[#hex+1] = toHex(byte)
         dump = dump .. " " .. toHex(byte)
     else
        progstart = progstart .. toHex(byte)
     end
     index = index + 1
  end
  f.close()
  print("Read " .. index .. " Bytes.")

  -- Load Hex into program memory
  -- Make sure interupt hasnt been called, if it has dont reset the program counter.
  if(tonumber(getFlag("BRK")) == 0)then
    setPC(progstart)
  else
    print("Break detected, resuming program.")
    print("press any key. ")
    setFlag("BRK",0)
    os.pullEvent("key")
  end
  -- Insert HEX into Program memory
  for i = 1, #hex do
    writeByte(toHex( tonumber(progstart,16)+(i-1) ),hex[i])
  end
  -- With program loaded, start running through it base on the program counter index
  local line = 1
  local hexstart = tonumber(progstart,16)
  -- Run program till its hex limit is reached.
  term.clear()
  term.setCursorPos(1, 1)
  while tonumber(readPC(),16) <= hexstart+(#hex-1) do
    if(tonumber(getFlag("BRK")) == 1)then
      term.setTextColor(colors.white)
      print("\nProgram brk at PC=$" .. readPC())
      break
    end
    -- Get key inputs / generate random numbers
    os.queueEvent("ASMWait")
    local ev = {os.pullEvent()}
    if(ev[1] == "key")then writeByte("FF",toHex(tonumber(ev[2]))) end
    writeByte("FE",toHex(math.random(0,255)))
    local args = {}
    local opperation = readByteHex(readPC())
    if(_G.ASM._OPCODES[opperation] == nil)then print(opperation .. " nil?") end
    local opBytes = _G.ASM._OPCODES[opperation].bytes
    for byteIndex = 1, opBytes do
      args[#args+1] = readByteHex(toHex((tonumber(readPC(),16)+byteIndex)))
    end
    -- Run command
    if(debug and _G.ASM.pmode ~= 2)then
      term.current().setVisible(false)
      term.clear()
      term.setCursorPos(1, 1)
      print("A: " .. readRegHex("A") .. " X: ".. readRegHex("X") .. " Y: " .. readRegHex("Y") .. " SP: " .. readRegHex("SP") .. " PC: " .. readPC())
      print("NZ-BDIZC")
      print(toBin(decodeByte(getFlagsByte())))
      for i = 1, #hex do
        local found = false
        local ind = tonumber(readPC(),16) - tonumber(progstart,16)
        if( (i-1) == ind)then
          term.setTextColor(colors.orange)
          write(hex[i] .. " ")
        else
          if(opBytes > 0)then
            for x = 1, opBytes do
              if((i-1)-x == ind)then
                term.setTextColor(colors.green)
                write(hex[i] .. " ")
                found = true
              end
            end
          end
          if not found then
            term.setTextColor(colors.white)
            write(hex[i] .. " ")
          end
        end
      end
    end
    term.current().setVisible(true)
    movePC(1)
    movePC(opBytes)
    _G.ASM._OPCODES[opperation]:exe(unpack(args))
    line = line + 1
    if(step)then
      if(_G.ASM.pmode ~= 2)then term.setCursorPos(1, 1) end
      term.setTextColor(colors.white)
      print("\nPress any key. ")
      os.pullEvent("key")
    end
  end
  if(tonumber(getFlag("BRK")) == 0)then
    term.setTextColor(colors.white)
    print("\nProgram end at PC=$" .. readPC())
  end
end

function AssembleASM(input,output,nout)
  if(nout == nil)then nout = false
  elseif(nout ~= "-y")then nout = false end
  if(nout == "-y")then nout = true end
  if(not fs.exists(input))then error("File doesnt exist: " .. input) end
  if(fs.exists(output))then error("File exists: " .. output) end
  local labels = {}
  local vars = {}
  bytearray = {}
  local keyword_var = "define"
  local keyword_label = ":"
  local keyword_begin = ".begin"
  local keyword_bytes = "dcb"
  local online = 1
  local codeline = 0
  local programstart = "0600"
  print("Reading file...")
  -- Safer to read file first, then compile as the fs hook is closed, and they is no risk of data loss.
  local source = fs.open(input,"r")
  local code = {}
  local line = source.readLine()
  while line do
    code[#code+1] = line
    line = source.readLine()
  end
  source.close()
  -- Compile Variables and labels, check for syntax errors
  print("Initializing...")
  for i = 1, #code do
    -- Handle variables
    if(code[i]:find(";"))then
      local nargs = {}
       for word in string.gmatch(code[i], '([^;]+)') do
          table.insert(nargs, word)
       end
       if(#nargs <= 1)then
        code[i] = ""
       else
        code[i] = nargs[1]
       end
    end

     if(code[i]:find(keyword_bytes))then
        local val = str_shearWord(code[i],keyword_bytes)
        if(code[i]:find(","))then
            for word in string.gmatch(val, '([^,]+)') do
                word = word:gsub("%s","")
                if(word:sub(1,1) ~= "$")then error("Syntax error line " .. online .. ": " .. code[i]) end
                if(word:sub(2,2) == "'")then
                    if(#word:sub(3,#word-1) ~= 1)then error("Syntax error line " .. online .. ": " .. code[i]) end
                    word = "$" .. toHex((string.byte(word:sub(3,#word-1))))
                end
                if(#word == 5)then
                    -- Divide and reverse order
                    word = "$" .. word:sub(4,5) .. word:sub(2,3)
                end

                bytearray[codeline] = word:sub(2,#word)
                codeline = codeline + 1
            end
        else
            if(val:sub(2,2) == "'")then
                if(#val:sub(3,#val-1) ~= 1)then error("Syntax error line " .. online .. ": " .. code[i]) end
                val = "$" .. toHex((string.byte(val:sub(3,#val-1))))
            end
            if(val:sub(1,1) ~= "$")then error("Syntax error line " .. online .. ": " .. code[i]) end
            bytearray[codeline] = val:sub(2,#val)
            codeline = codeline + 1
        end
    end

    if(code[i]:find(keyword_begin))then
        local val = str_shearWord(code[i],keyword_begin)
        if(val:sub(1,1) ~= "$")then error("Syntax error line " .. online .. ": " .. code[i]) end
        if(codeline ~= 0)then error("Syntax error line " .. online .. ": " .. code[i] .. " :>  Must be placed only at start of file.") end
        programstart = val:sub(2,#val)
    end
    if(code[i]:find(keyword_var))then
       local val = str_shearWord(code[i],keyword_var)
       local nargs = {}
       -- Take spaces out of string, then split it into 2 variables
       val = val:gsub("%s+", "")
       -- Split string by $
       for word in string.gmatch(val, '([^$]+)') do
          table.insert(nargs, word)
       end
        if(#nargs > 2)then error("Syntax error line " .. online .. ": " .. code[i]) end
        -- Convert ASCII to hex
        if(nargs[2]:sub(1,1) == "'")then
          if(nargs[2]:sub(3,3) ~= "'")then error("Syntax error line " .. online .. ": " .. code[i]) end
          nargs[2] = toHex(string.byte(nargs[2]:sub(2,#nargs))) -- ToHex needed upon converted chars their respective byte.
          -- Using SUB because the string is split up into sections from the $ char, sub is needed to remove the ''.
        end
         -- if(_G.ASM._HEXENCODE[string.upper(nargs[1])])then error("Syntax error line " .. online .. ": " .. code[i]) end
       vars[nargs[1]] = nargs[2]
      -- print(nargs[1] .. ": " .. vars[nargs[1]])
    end
    -- Handle labels
    if(code[i]:find(keyword_label))then
      local val = code[i]:gsub("%s+","")
      local nargs = {}
       for word in string.gmatch(val, '([^:]+)') do
          table.insert(nargs, word)
       end
       if(#nargs > 1 or nargs == nil)then
         error("Syntax error line " .. online .. ": " .. code[i])
       end
       labels[nargs[1]] = codeline
      -- print(nargs[1] .. ": " .. labels[nargs[1]])
    end
    online = online + 1
    if(#code[i]:gsub("%s+","") ~= 0 and not code[i]:find(keyword_label) and not code[i]:find(keyword_var) and not code[i]:find(keyword_begin) and not code[i]:find(keyword_bytes))then
      codeline = codeline + 1
    end
  end

  -- Get Bytes Per line
  codeline = 0
  online = 1
  linebytes = {}
  local loadedbytes = false
  code_backup = code -- LUA bug where this variable acts like a pointer and still writes to code.
  print("Getting Bytes...")
  -- Process each defined byte
  for i = 1, #code_backup do
    if(code[i]:find(";"))then
      local nargs = {}
       for word in string.gmatch(code[i], '([^;]+)') do
          table.insert(nargs, word)
       end
       if(#nargs <= 1)then
        code[i] = ""
       else
        code[i] = nargs[1]
       end
    end
    -- Calculate defined bytes
     if(code_backup[i]:find(keyword_bytes))then
        local val = str_shearWord(code[i],keyword_bytes)
        if(code_backup[i]:find(","))then
            for word in string.gmatch(val, '([^,]+)') do
                word = word:gsub("%s","")
                if(word:sub(1,1) ~= "$")then error("Syntax error line " .. online .. ": " .. code_backup[i]) end
                if(word:sub(2,2) == "'")then
                    if(#word:sub(3,#word-1) ~= 1)then error("Syntax error line " .. online .. ": " .. code_backup[i]) end
                end
                if(#word == 5)then
                    -- Divide and reverse order
                    linebytes[#linebytes+1] = 2
                else
                    linebytes[#linebytes+1] = 1
                end
            end
        else
            if(val:sub(2,2) == "'")then
                if(#val:sub(3,#val-1) ~= 1)then error("Syntax error line " .. online .. ": " .. code[i]) end
                linebytes[#linebytes+1] = 1
            else
                linebytes[#linebytes+1] = 1
            end
            if(val:sub(1,1) ~= "$")then error("Syntax error line " .. online .. ": " .. code[i]) end
            codeline = codeline + 1
        end
    end

    if(#code_backup[i]:gsub("%s+","") ~= 0 and not code_backup[i]:find(keyword_label) and not code_backup[i]:find(keyword_var) and not code_backup[i]:find(keyword_begin) and not code_backup[i]:find(keyword_bytes))then
      local op  = string.upper(code_backup[i]:gsub("%s+",""):sub(1,3))
      local vtype = code_backup[i]:gsub("%s+",""):sub(4,4)
      local opperand = ""
      local prefix = ""
      local val = code_backup[i]:gsub("%s+",""):sub(4,#code_backup[i])
      if(code[i]:find(","))then
            local ends = {}
            for word in string.gmatch(code[i], '([^,]+)') do
                table.insert(ends, word)
            end
            val = str_shearWord(ends[1],op)
            opperand = ", " .. ends[2]:gsub("%s","")
            if(code[i]:find("%("))then
                if(string.lower(ends[2]:gsub("%s","")) == "y")then
                    opperand = ")" .. opperand
                end
                prefix = "("
            end
      end
      if(val:sub(1,1) == "#")then val = val:sub(2,#val) end
      if(not _G.ASM._HEXENCODE[op])then error("Syntax error line " .. online .. ": " .. code_backup[i]) end
      if(vars[val] ~= nil)then
        if(_G.ASM._HEXENCODE[op]['REL'] ~= nil)then
          error("Syntax error line " .. online .. ": " .. code_backup[i])
        end
        if(vtype == "#")then
          code_backup[i] = op .. " #$" .. vars[val] .. opperand
        else
          if(not tonumber(vars[val],16))then error("Syntax error line " .. online .. ": " .. code_backup[i]) end
          code_backup[i] = op .. " $" .. vars[val] .. opperand
        end
      elseif(labels[val] ~= nil)then
        if(_G.ASM._HEXENCODE[op]['REL'] ~= nil)then
          code_backup[i] = op .. " *+" .. "00"
        else
          code_backup[i] = op .. " $" .. "0000" .. opperand
        end
      end
          -- Variable encoding
         val = val:gsub("[()]","")
        if(vars[val] ~= nil)then
            if(_G.ASM._HEXENCODE[op]['REL'] ~= nil)then
              -- No variable branching!
              error("Syntax error line " .. online .. ": " .. code_backup[i])
            end
            if(vtype == "#")then
              code[i] = op .. " " .. prefix .. "#$" .. vars[val] .. opperand
              --print(code[i])
            else
              -- Direct index
              if(not tonumber(vars[val],16))then error("Syntax error line " .. online .. ": " .. code[i]) end
              code[i] = op .. " " .. prefix .. "$" .. vars[val] .. opperand
              --print(code[i])
            end
        end
      codeline = codeline + 1
      local opr, otype, num = procInstructionType(code_backup[i],false,false)
      if(lineB == "op")then error("Syntax error line " .. online .. ": " .. code_backup[i]) end
      if(otype == nil)then otype = "err" end
      print(opr .. ": " .. otype)
      local lineB = getInstuctionBytes(opr,otype)
      if(lineB == "err")then error("Syntax error line " .. online .. ": " .. code_backup[i]) end
      linebytes[#linebytes+1] = lineB
      --print(#linebytes .. ": " .. lineB)
      --os.pullEvent("key")
    end
    online = online + 1
  end
  -- Compile Code substitute variables and labels, check syntax
  -- Branch labels and jump labels, are controlled based on additions to the base program start
  codeline = 0
  online = 1
  local source = fs.open(input,"r")
  local code = {}
  local line = source.readLine()
  while line do
    code[#code+1] = line
    line = source.readLine()
  end
  source.close()
  local hexdump = ""
  print("Compiling code...")
  for i = 1, #code do
    if(code[i]:find(";"))then
      local nargs = {}
       for word in string.gmatch(code[i], '([^;]+)') do
          table.insert(nargs, word)
       end
       if(#nargs <= 1)then
        code[i] = ""
       else
        code[i] = nargs[1]
       end
    end
    if(#code[i]:gsub("%s+","") ~= 0 and not code[i]:find(keyword_label) and not code[i]:find(keyword_var) and not code[i]:find(keyword_begin) and not code[i]:find(keyword_bytes))then
      -- Check if code references label or variable
      local op  = string.upper(code[i]:gsub("%s+",""):sub(1,3))
      local vtype = code[i]:gsub("%s+",""):sub(4,4)
      local opperand = ""
      local prefix = ""
      local val = code[i]:gsub("%s+",""):sub(4,#code[i])
      if(val:sub(1,1) == "#")then val = val:sub(2,#val) end
      if(code[i]:find(","))then
            local ends = {}
            for word in string.gmatch(code[i], '([^,]+)') do
                table.insert(ends, word)
            end
            val = str_shearWord(ends[1],op)
            opperand = ", " .. ends[2]:gsub("%s","")
            if(code[i]:find("%("))then
                if(string.lower(ends[2]:gsub("%s","")) == "y")then
                    opperand = ")" .. opperand
                end
                prefix = "("
            end
      end
      val = val:gsub("[()]","")
      if(not _G.ASM._HEXENCODE[op])then error("Syntax error line " .. online .. ": " .. code[i]) end
      if(vars[val] ~= nil)then
        if(_G.ASM._HEXENCODE[op]['REL'] ~= nil)then
          -- No variable branching!
          error("Syntax error line " .. online .. ": " .. code[i])
        end
        if(vtype == "#")then
          code[i] = op .. " " .. prefix .. "#$" .. vars[val] .. opperand
          --print(code[i])
        else
          -- Direct index
          if(not tonumber(vars[val],16))then error("Syntax error line " .. online .. ": " .. code[i]) end
          code[i] = op .. " " .. prefix .. "$" .. vars[val] .. opperand
          --print(code[i])
        end
      elseif(labels[val] ~= nil)then
        -- Insert for relative branching
        --error("Labels do not work yet (And may never work)")
        local bytediff = 0
        branches = {}
          for i = 1, #linebytes do
            if(i > 1)then
              branches[i] = branches[i-1] + linebytes[i]
            else
              branches[i] = linebytes[i]
            end
          end
        if(_G.ASM._HEXENCODE[op]['REL'] ~= nil)then

          -- Jump difference
          local difference = (branches[labels[val]] - branches[codeline+1])

          if(difference < -128 or difference > 127)then
              error("Out of range branch on line " .. online .. " (branches are limited to -128 to +127): " .. code[i] .. "(" .. difference .. ") ")
          end

          if(difference < 0)then
            -- Subtract the amount of bytes taken by branch
            difference = 256 + difference
          end
          difference = toHex(difference)
          -- Insert branch difference into code
          code[i] = op .. " *+" .. difference
          --print(code[i])
        else
          -- Insert for jumping
          local newBase = toHex(tonumber(programstart,16) + branches[labels[val]])
          if(#newBase < 4)then newBase = string.rep("0",4-#newBase) .. newBase end
          code[i] = op .. " $" .. newBase .. opperand
          --print(code[i])
        end
      end
      local hex = AssembleHEX(code[i],online)
      hexdump = hexdump .. hex
      codeline = codeline + 1
    end
    online = online + 1

    -- if DCB, replace with the raw bytes
    -- Calculate defined bytes
     if(code[i]:find(keyword_bytes))then
        local val = str_shearWord(code[i],keyword_bytes)
        local hex = ""
        local wInd = 0
        if(code[i]:find(","))then
            for word in string.gmatch(val, '([^,]+)') do
                word = word:gsub("%s","")
                if(word:sub(1,1) ~= "$")then error("Syntax error line " .. online .. ": " .. code[i]) end
                if(word:sub(2,2) == "'")then
                    if(#word:sub(3,#word-1) ~= 1)then error("Syntax error line " .. online .. ": " .. code[i]) end
                    word = "$" .. toHex(string.byte(word:sub(3,3)))
                end
                code[wInd] = word:sub(2,#word)
                hex = word:sub(2,#word)
                wInd = wInd +1
                if(#hex == 4)then
                    hex = hex:sub(1,2) .. " " .. hex:sub(3,4)
                end
                hexdump = hexdump .. hex .. " "
                codeline = codeline+1
            end
        else
            if(val:sub(2,2) == "'")then
                if(#val:sub(3,#val-1) ~= 1)then error("Syntax error line " .. online .. ": " .. code[i]) end
                val = toHex(string.byte(val:sub(3,3)))
                code[i] = val
                hex = val
            else
                code[i] = val:sub(2,#val)
                hex = val:sub(2,#val)
            end
            if(val:sub(1,1) ~= "$")then error("Syntax error line " .. online .. ": " .. code[i]) end
            if(#hex == 4)then
                hex = hex:sub(1,2) .. " " .. hex:sub(3,4)
            end
            hexdump = hexdump .. hex .. " "
            codeline = codeline + 1
        end
    end
  end

  -- Compile hex to bytes
  local hexbytes = ""
  local _hexdump = hexdump
  hexdump = hexdump:gsub("%s+","")
  if(hexdump == "")then
     print("No code to run.")
     return
  end
  if(#hexdump > 2)then
      for i=1, #hexdump, 2 do
          hexbytes = hexbytes .. string.char(tonumber(hexdump:sub(i,i+1),16))
      end
  else
    hexbytes = string.char(tonumber(hexdump,16))
  end
  print("Hex Compiled: " .. _hexdump)
  if(nout == false)then
    local f = fs.open(output,"wb")
    for i=1, #hexdump, 2 do
        if(i == 1)then
            -- Program counter encoding.
            f.write(tonumber(programstart:sub(1,2),16))
            f.write(tonumber(programstart:sub(3,4),16))
        end
        f.write(tonumber(hexdump:sub(i, i + 1), 16))
    end
    f.close()
    print("Hex outputed to: " .. output)
    print("Done. ")
    --os.pullEvent("key")
  end
end

local function StartSyntaxInterpreter()
  print("Starting Syntax Interpreter (type \"exit\" to exit.)")
  local running = true
  local function getinp()
    local opperation = read()
    if(opperation == "exit")then
      if(_CCENV)then
         print("Returning to CraftOS.")
      else
         print("Returning to LUA.")
      end
      running = false
    end
    local op, type, val = procInstructionType(opperation,true)
    runOpperation(op,type,val,true)
    print("A: " .. readRegHex("A") .. " X: ".. readRegHex("X") .. " Y: " .. readRegHex("Y") .. " SP: " .. readRegHex("SP") .. " PC: " .. readPC())
    print(toBin(decodeByte(getFlagsByte())))
  end
  while running do

    write("Ready :> ")
    local gd, err = pcall(getinp)
    if(not ok and err and running)then print(err) end --print(err:sub(11,#err)) end
  end
end

if(not _G.ASM and shell)then
  print("6502: Not Initialized, press any key. ")
  os.pullEvent("key")
  initalize()
  print("Memory testing...")
  writeByte("1","0C")
  writeByte("2","0C")
  writeByte("3","0C")
  writeByte("FFFF","0C")
  print("Retrieving...")
  readByte("1",true)
  readByte("2",true)
  readByte("3",true)
  readByte("FFFF",true)
  print("Memory check successful!, re-initalizing...")
  writeByte("1","0")
  writeByte("2","0")
  writeByte("3","0")
  writeByte("FFFF","0")
  print("Memory: " .. _G.ASM.MSIZE .. "B free. \n")
  print("Ready. ")
  sleep(0.5)
  term.clear()
  term.setCursorPos(1,1)
elseif(not shell and not _G.ASM)then
    initalize()
end


-- Program Arguments Use
local progargs = { ... }
-- Arguments -i, -c, -r, interpreter, compile, run
-- If this program is not being loaded as an API
if(shell ~= nil)then
    if(#progargs == 0)then
      print("Usage: " .. shell.resolve(shell.getRunningProgram()) .. " -<mode> <args> \n")
      print("Modes -> -i, -c, -r, -rn, -m, -d")
      print("-i  Starts 6502 Interpreter. ")
      print("-c  Compiles <file>, outputs hex to <output>.")
      print("-r  Runs compiled ASM hex <file>. ")
      print("-rn Runs the <file> without exporting it.")
      print("-m  Sets run <mode>: [1 - Text] [2 - Graphics]" )
      print("-d  Exports Disassembled ASM from <source> to <output>")
    end
    if(not _CCENV)then
        local mode = io.read()
        for word in string.gmatch(mode, '([^ ]+)') do
          table.insert(progargs, word)
        end
    end

    if(progargs[1] == "-i")then
      StartSyntaxInterpreter()
    elseif(progargs[1] == "-c")then
      if(#progargs < 3)then error("Usage: -i <source> <output>") end
      AssembleASM(progargs[2],progargs[3],progargs[4])
    elseif(progargs[1] == "-r")then
      if(#progargs < 2)then error("Usage: -r <compiled asm>") end
      runCompiledASM(progargs[2],progargs[3],progargs[4])
    elseif(progargs[1] == "-rn")then
      if(#progargs < 2)then error("Usage: -rn <source>") end
      if(fs.exists("/.tempasm"))then fs.delete("/.tempasm") end
      AssembleASM(progargs[2],"/.tempasm",progargs[3])
    if(fs.exists("/.tempasm"))then
        runCompiledASM("/.tempasm",progargs[3],progargs[4])
    end
      fs.delete("/.tempasm")
    elseif(progargs[1] == "-m")then
       if(#progargs < 2)then error("Usage: -m <mode>") end
       local mode = tonumber(progargs[2])
       if(progargs[2] == "2")then
          print("Programs set to run in Graphics mode.")
       elseif(progargs[2] == "1")then
          print("Programs set to run in Text mode.")
       else
          print("Unknown mode: " .. progargs[2])
          mode = 1
       end
       _G.ASM.pmode = mode
    elseif(progargs[1] == "-d")then
          if(#progargs < 3)then error("Usage: -d <compiled asm> <output>") end
          if(not fs.exists(progargs[2]))then error("No such file: " .. progargs[2]) end
          local asmc = disassembleASM(progargs[2])
          local f = fs.open(progargs[3],"w")
          f.writeLine("Address  Hexdump   Dissassembly")
          f.writeLine("-------------------------------")
          f.write(asmc)
          f.close()
          print("Disassembly outputed to: " .. progargs[3])
    end
end