diff --git a/Lua/lib/lips/Expander.lua b/Lua/lib/lips/Expander.lua
index 08e885f..95d9efe 100644
--- a/Lua/lib/lips/Expander.lua
+++ b/Lua/lib/lips/Expander.lua
@@ -31,6 +31,8 @@ function Expander:pop(kind)
         ret = self.s[self.i]
     elseif kind == 'CPU' then
         ret = self:register(data.registers)
+    elseif kind == 'FPU' then
+        ret = self:register(data.fpu_registers)
     elseif kind == 'DEREF' then
         ret = self:deref()
     elseif kind == 'CONST' then
diff --git a/Lua/lib/lips/Expression.lua b/Lua/lib/lips/Expression.lua
index 022c765..5634c3a 100644
--- a/Lua/lib/lips/Expression.lua
+++ b/Lua/lib/lips/Expression.lua
@@ -144,22 +144,39 @@ function Expression:lex1(str, tokens)
         local here = " (#"..tostring(pos)..")"
         if consider(' +') then
             consume(#considered)
-        elseif consider('[0-9.]') then
+        elseif consider('[0-9.]') or consider('[%%$#]') then
             local num
             if consider('((0|[1-9][0-9]*)%.[0-9]*|%.[0-9]+)(e0|e[1-9][0-9]*)?') then
                 num = tonumber(considered)
             elseif consider('(0|[1-9][0-9]*)e(0|[1-9][0-9]*)') then
                 num = tonumber(considered)
-            elseif consider('[0-1]+b') then
-                num = tonumber(considered, 2)
+            elseif consider('%%[0-9]+') then
+                if considered:match('[2-9]') then
+                    return "bad binary number: "..considered..here
+                end
+                num = tonumber(considered:sub(2), 2)
+            elseif consider('$[0-9A-Fa-f]+') then
+                num = tonumber(considered:sub(2), 16)
             elseif consider('0x[0-9A-Fa-f]+') then
-                num = tonumber(considered, 16)
+                num = tonumber(considered:sub(3), 16)
+            elseif consider('0o[0-9]+') then
+                if considered:match('[89]') then
+                    return "bad octal number: "..considered..here
+                end
+                num = tonumber(considered:sub(3), 8)
+            elseif consider('0b[0-9]+') then
+                if considered:match('[2-9]') then
+                    return "bad binary number: "..considered..here
+                end
+                num = tonumber(considered:sub(3), 2)
             elseif consider('0[0-9]+') then
                 if considered:match('[89]') then
                     return "bad octal number: "..considered..here
                 end
-                num = tonumber(considered, 8)
-            elseif consider('[0-9]*') then
+                num = tonumber(considered:sub(2), 8)
+            elseif consider('#[0-9]+') then
+                num = tonumber(considered:sub(2))
+            elseif consider('[0-9]+') then
                 num = tonumber(considered)
             end
             if num == nil then
@@ -176,7 +193,7 @@ function Expression:lex1(str, tokens)
         elseif consider_operator() then
             insert(tokens, {type='operator', value=considered})
             consume(#considered)
-        elseif consider('%w+') then
+        elseif consider('[%w_]+') then
             local num = self.variables[considered]
             if num == nil then
                 return 'undefined variable "'..considered..'"'
diff --git a/Lua/lib/lips/Lexer.lua b/Lua/lib/lips/Lexer.lua
index ff7318c..a8617a6 100644
--- a/Lua/lib/lips/Lexer.lua
+++ b/Lua/lib/lips/Lexer.lua
@@ -3,6 +3,7 @@ local char = string.char
 local find = string.find
 local format = string.format
 local insert = table.insert
+local unpack = rawget(_G, 'unpack') or table.unpack
 
 local path = string.gsub(..., "[^.]+$", "")
 local data = require(path.."data")
@@ -15,6 +16,7 @@ local simple_escapes = {
     ['"']   = 0x22,
     ['a']   = 0x07,
     ['b']   = 0x08,
+    ['e']   = 0x1B,
     ['f']   = 0x0C,
     ['n']   = 0x0A,
     ['r']   = 0x0D,
@@ -263,6 +265,18 @@ function Lexer:lex_string(yield)
             local simple = simple_escapes[self.chr]
             if simple then
                 insert(bytes, simple)
+            elseif self.chr == 'x' then
+                self:nextc()
+                local hex = self.chrchr
+                if not self.chr:find('[0-9a-fA-F]') then
+                    self:error('invalid hex escape sequence: \\x'..hex)
+                end
+                self:nextc()
+                if not self.chr:find('[0-9a-fA-F]') then
+                    self:error('invalid hex escape sequence: \\x'..hex)
+                end
+                local byte = tonumber(hex, 16)
+                insert(bytes, byte)
             else
                 self:error('unknown escape sequence')
             end
@@ -276,32 +290,27 @@ function Lexer:lex_string(yield)
     yield('STRING', bytes)
 end
 
-function Lexer:lex_string_naive(yield) -- no escape sequences
-    if self.chr ~= '"' then
-        self:error('expected opening double quote')
-    end
-    self:nextc()
-    local buff = self:read_chars('[^"\n]')
-    if self.chr ~= '"' then
-        self:error('expected closing double quote')
-    end
-    self:nextc()
-    yield('STRING', buff)
-end
-
 function Lexer:lex_filename(_yield)
     self:read_spaces()
-    local fn
-    self:lex_string_naive(function(tt, tok)
-        fn = tok
+    local fn = ''
+    self:lex_string(function(tt, tok)
+        fn = char(unpack(tok))
     end)
     _yield('STRING', fn, self.fn, self.line)
 
-    if self.chr ~= '\n' then
+    self:read_spaces()
+    if self.chr == ';' or self.chrchr == '//' then
+        self:skip_to_EOL()
+    end
+    if self.chr == '\n' then
+        _yield('EOL', '\n', self.fn, self.line)
+        self:nextc()
+    elseif self.ord == self.EOF then
+        _yield('EOL', '\n', self.fn, self.line)
+        self.was_EOL = true
+    else
         self:error('expected EOL after filename')
     end
-    _yield('EOL', '\n', self.fn, self.line)
-    self:nextc()
 
     return fn
 end
diff --git a/Lua/lib/lips/TokenIter.lua b/Lua/lib/lips/TokenIter.lua
index a63032f..70dca0e 100644
--- a/Lua/lib/lips/TokenIter.lua
+++ b/Lua/lib/lips/TokenIter.lua
@@ -184,7 +184,8 @@ function TokenIter:special()
 
     local args = {}
     while true do
-        local arg = self:advance()
+        self:advance()
+        local arg = self.t
         if not self.arg_types[arg.tt] then
             self:error('invalid argument type', arg.tt)
         else
diff --git a/Lua/lib/lips/overrides.lua b/Lua/lib/lips/overrides.lua
index b4b4f01..8470847 100644
--- a/Lua/lib/lips/overrides.lua
+++ b/Lua/lib/lips/overrides.lua
@@ -49,9 +49,10 @@ end
 local overrides = {}
 -- note: "self" is an instance of Expander
 
+local fpu_tob = {}
 local function tob_override(self, name)
     -- handle all the addressing modes for lw/sw-like instructions
-    local dest = self:pop('CPU')
+    local dest = fpu_tob[name] and self:pop('FPU') or self:pop('CPU')
     local offset, base
     if self:peek('DEREF') then
         offset = 0
@@ -96,6 +97,9 @@ end
 for k, v in pairs(data.instructions) do
     if v[2] == 'tob' then
         overrides[k] = tob_override
+    elseif v[2] == 'Tob' then
+        fpu_tob[k] = true
+        overrides[k] = tob_override
     end
 end
 
diff --git a/Lua/lib/lips/writers.lua b/Lua/lib/lips/writers.lua
index 45bf6d8..63e9a52 100644
--- a/Lua/lib/lips/writers.lua
+++ b/Lua/lib/lips/writers.lua
@@ -82,4 +82,32 @@ function writers.make_tester()
     end
 end
 
+function writers.make_gameshark()
+    local buff = {}
+    local max = -1
+    return function(pos, b)
+        if pos then
+            pos = pos % 0x80000000
+            buff[pos] = b
+            if pos > max then
+                max = pos
+            end
+        elseif max >= 0 then
+            for i=0, max, 2 do
+                local a = buff[i+0]
+                local b = buff[i+1]
+                a = a and ("%02X"):format(a)
+                b = b and ("%02X"):format(b)
+                if a and b then
+                    print(('81%06X %s'):format(i, a..b))
+                elseif a then
+                    print(('80%06X 00%s'):format(i, a))
+                elseif b then
+                    print(('80%06X 00%s'):format(i + 1, b))
+                end
+            end
+        end
+    end
+end
+
 return writers