diff --git a/build.properties b/build.properties
index de6d33365..e9d4b2e25 100644
--- a/build.properties
+++ b/build.properties
@@ -1,7 +1,7 @@
 minecraft.version=1.7.10
 forge.version=10.13.4.1614-1.7.10
 
-oc.version=1.7.3
+oc.version=1.7.4
 
 ae2.version=rv2-beta-26
 bc.version=7.0.9
diff --git a/src/main/resources/assets/opencomputers/loot/openos/bin/mktmp.lua b/src/main/resources/assets/opencomputers/loot/openos/bin/mktmp.lua
index abcc1ec18..9fab5d2dc 100644
--- a/src/main/resources/assets/opencomputers/loot/openos/bin/mktmp.lua
+++ b/src/main/resources/assets/opencomputers/loot/openos/bin/mktmp.lua
@@ -13,17 +13,18 @@ end
 
 local args, ops = shell.parse(...)
 
-local function pop(key)
-  local result = ops[key]
-  ops[key] = nil
+local function pop(...)
+  local result
+  for _,key in ipairs({...}) do
+    result = ops[key] or result
+    ops[key] = nil
+  end
   return result
 end
 
 local directory = pop('d')
-local verbose = pop('v')
-verbose = pop('verbose') or verbose
-local quiet = pop('q') or quiet
-quiet = pop('quiet') or quiet
+local verbose = pop('v', 'verbose')
+local quiet = pop('q', 'quiet')
 
 if pop('help') or #args > 1 or next(ops) then
   print([[Usage: mktmp [OPTION] [PATH]
diff --git a/src/main/resources/assets/opencomputers/loot/openos/bin/sh.lua b/src/main/resources/assets/opencomputers/loot/openos/bin/sh.lua
index aee3d82b2..ae33bd3c9 100644
--- a/src/main/resources/assets/opencomputers/loot/openos/bin/sh.lua
+++ b/src/main/resources/assets/opencomputers/loot/openos/bin/sh.lua
@@ -3,20 +3,22 @@ local tty = require("tty")
 local text = require("text")
 local sh = require("sh")
 
-local args, options = shell.parse(...)
+local args = shell.parse(...)
 
 shell.prime()
-local needs_profile = io.input().tty
-local has_prompt = needs_profile and io.output().tty and not options.c
-local input_handler = {hint = sh.hintHandler}
 
 if #args == 0 then
+  local has_profile
+  local input_handler = {hint = sh.hintHandler}
   while true do
-    if has_prompt then
-      if needs_profile then -- first time run AND interactive
-        needs_profile = nil
+    if io.stdin.tty and io.stdout.tty then
+      if not has_profile then -- first time run AND interactive
+        has_profile = true
         dofile("/etc/profile.lua")
       end
+      if tty.getCursor() > 1 then
+        io.write("\n")
+      end
       io.write(sh.expand(os.getenv("PS1") or "$ "))
     end
     tty.window.cursor = input_handler
@@ -27,6 +29,7 @@ if #args == 0 then
       if command == "exit" then
         return
       elseif command ~= "" then
+        --luacheck: globals _ENV
         local result, reason = sh.execute(_ENV, command)
         if not result then
           io.stderr:write((reason and tostring(reason) or "unknown error") .. "\n")
@@ -35,9 +38,6 @@ if #args == 0 then
     elseif command == nil then -- false only means the input was interrupted
       return -- eof
     end
-    if has_prompt and tty.getCursor() > 1 then
-      io.write("\n")
-    end
   end
 else
   -- execute command.
diff --git a/src/main/resources/assets/opencomputers/loot/openos/etc/motd b/src/main/resources/assets/opencomputers/loot/openos/etc/motd
index 58c4b014b..0c73a8250 100644
--- a/src/main/resources/assets/opencomputers/loot/openos/etc/motd
+++ b/src/main/resources/assets/opencomputers/loot/openos/etc/motd
@@ -14,7 +14,7 @@ if f then
   f:close()
   greeting = greetings[math.random(1, math.max(#greetings, 1))] or ""
 end
-local width = math.min(#greeting, tty.getViewport() - 5)
+local width = math.min(#greeting, (tty.getViewport() or math.huge) - 5)
 local maxLine = #lines[1]
 while #greeting > 0 do
   local si, ei = greeting:sub(1, width):find("%s%S*$")
diff --git a/src/main/resources/assets/opencomputers/loot/openos/lib/core/boot.lua b/src/main/resources/assets/opencomputers/loot/openos/lib/core/boot.lua
index 904b7e905..4e51bf576 100644
--- a/src/main/resources/assets/opencomputers/loot/openos/lib/core/boot.lua
+++ b/src/main/resources/assets/opencomputers/loot/openos/lib/core/boot.lua
@@ -1,8 +1,9 @@
 -- called from /init.lua
 local raw_loadfile = ...
 
-_G._OSVERSION = "OpenOS 1.7.3"
+_G._OSVERSION = "OpenOS 1.7.4"
 
+-- luacheck: globals component computer unicode _OSVERSION
 local component = component
 local computer = computer
 local unicode = unicode
@@ -20,28 +21,23 @@ computer.shutdown = function(reboot)
   shutdown(reboot)
 end
 
-local screen = component.list('screen', true)()
-for address in component.list('screen', true) do
-  if #component.invoke(address, 'getKeyboards') > 0 then
-    screen = address
-    break
-  end
-end
-
-_G.boot_screen = screen
-
--- Report boot progress if possible.
-local gpu = component.list("gpu", true)()
 local w, h
-if gpu and screen then
+local screen = component.list("screen", true)()
+local gpu = screen and component.list("gpu", true)()
+if gpu then
   gpu = component.proxy(gpu)
-  gpu.bind(screen)
+  if not gpu.getScreen() then
+    gpu.bind(screen)
+  end
+  _G.boot_screen = gpu.getScreen()
   w, h = gpu.maxResolution()
   gpu.setResolution(w, h)
   gpu.setBackground(0x000000)
   gpu.setForeground(0xFFFFFF)
   gpu.fill(1, 1, w, h, " ")
 end
+
+-- Report boot progress if possible.
 local y = 1
 local uptime = computer.uptime
 -- we actually want to ref the original pullSignal here because /lib/event intercepts it later
@@ -49,7 +45,7 @@ local uptime = computer.uptime
 local pull = computer.pullSignal
 local last_sleep = uptime()
 local function status(msg)
-  if gpu and screen then
+  if gpu then
     gpu.set(1, y, msg)
     if y == h then
       gpu.copy(1, 2, w, h - 1, 0, -1)
diff --git a/src/main/resources/assets/opencomputers/loot/openos/lib/core/full_filesystem.lua b/src/main/resources/assets/opencomputers/loot/openos/lib/core/full_filesystem.lua
index 1a67f1763..fdf55dc79 100644
--- a/src/main/resources/assets/opencomputers/loot/openos/lib/core/full_filesystem.lua
+++ b/src/main/resources/assets/opencomputers/loot/openos/lib/core/full_filesystem.lua
@@ -335,6 +335,7 @@ function filesystem.setAutorunEnabled(value)
   saveConfig()
 end
 
+-- luacheck: globals os
 os.remove = filesystem.remove
 os.rename = filesystem.rename