diff --git a/sys/apis/terminal.lua b/sys/apis/terminal.lua
index 214e4ec..e73d822 100644
--- a/sys/apis/terminal.lua
+++ b/sys/apis/terminal.lua
@@ -100,9 +100,9 @@ function Terminal.window(parent, sx, sy, w, h, isVisible)
 	end
 
 	function win.setCursorPos(x, y)
-		cx, cy = x, y
+		cx, cy = math.floor(x), math.floor(y)
 		if isVisible then
-			parent.setCursorPos(x + canvas.x - 1, y + canvas.y - 1)
+			parent.setCursorPos(cx + canvas.x - 1, cy + canvas.y - 1)
 		end
 	end
 
diff --git a/sys/apis/trace.lua b/sys/apis/trace.lua
index ddb023c..4323003 100644
--- a/sys/apis/trace.lua
+++ b/sys/apis/trace.lua
@@ -85,7 +85,7 @@ return function (fn, ...)
     end
 
     for _, line in pairs(trace) do
-      _G._debug(line)
+      _G._syslog(line)
     end
 
     -- If this traceback is more than 15 elements long, keep the first 9, last 5
diff --git a/sys/apis/ui/canvas.lua b/sys/apis/ui/canvas.lua
index c7fbca3..b7969b0 100644
--- a/sys/apis/ui/canvas.lua
+++ b/sys/apis/ui/canvas.lua
@@ -199,13 +199,15 @@ function Canvas:blit(x, y, text, bg, fg)
 			end
 
 			local line = self.lines[y]
-			line.dirty = true
-			line.text = replace(line.text, x, text, width)
-			if fg then
-				line.fg = replace(line.fg, x, fg, width)
-			end
-			if bg then
-				line.bg = replace(line.bg, x, bg, width)
+			if line then
+				line.dirty = true
+				line.text = replace(line.text, x, text, width)
+				if fg then
+					line.fg = replace(line.fg, x, fg, width)
+				end
+				if bg then
+					line.bg = replace(line.bg, x, bg, width)
+				end
 			end
 		end
 	end
diff --git a/sys/apps/network/transport.lua b/sys/apps/network/transport.lua
index 2eeb801..eccd9ef 100644
--- a/sys/apps/network/transport.lua
+++ b/sys/apps/network/transport.lua
@@ -33,7 +33,7 @@ function transport.read(socket)
 end
 
 function transport.write(socket, data)
-	--_debug('>> ' .. Util.tostring({ type = 'DATA', seq = socket.wseq }))
+	--_syslog('>> ' .. Util.tostring({ type = 'DATA', seq = socket.wseq }))
 	socket.transmit(socket.dport, socket.dhost, data)
 
 	--local timerId = os.startTimer(3)
@@ -45,7 +45,7 @@ function transport.write(socket, data)
 end
 
 function transport.ping(socket)
-	--_debug('>> ' .. Util.tostring({ type = 'DATA', seq = socket.wseq }))
+	--_syslog('>> ' .. Util.tostring({ type = 'DATA', seq = socket.wseq }))
 	if os.clock() - socket.activityTimer > 10 then
 		socket.activityTimer = os.clock()
 		socket.transmit(socket.dport, socket.dhost, {
@@ -78,9 +78,9 @@ Event.on('modem_message', function(_, _, dport, dhost, msg, distance)
 		local socket = transport.sockets[dport]
 		if socket and socket.connected then
 
-			--if msg.type then _debug('<< ' .. Util.tostring(msg)) end
+			--if msg.type then _syslog('<< ' .. Util.tostring(msg)) end
 			if socket.co and coroutine.status(socket.co) == 'dead' then
-				_G._debug('socket coroutine dead')
+				_G._syslog('socket coroutine dead')
 				socket:close()
 
 			elseif msg.type == 'DISC' then
@@ -111,9 +111,9 @@ Event.on('modem_message', function(_, _, dport, dhost, msg, distance)
 				socket.activityTimer = os.clock()
 				if msg.seq ~= socket.rseq then
 					print('transport seq error - closing socket ' .. socket.sport)
-					_debug(msg.data)
-					_debug('current ' .. socket.rseq)
-					_debug('expected ' .. msg.seq)
+					_syslog(msg.data)
+					_syslog('current ' .. socket.rseq)
+					_syslog('expected ' .. msg.seq)
 --					socket:close()
 --					os.queueEvent('transport_' .. socket.uid)
 				else
@@ -125,7 +125,7 @@ Event.on('modem_message', function(_, _, dport, dhost, msg, distance)
 						os.queueEvent('transport_' .. socket.uid)
 					end
 
-					--_debug('>> ' .. Util.tostring({ type = 'ACK', seq = msg.seq }))
+					--_syslog('>> ' .. Util.tostring({ type = 'ACK', seq = msg.seq }))
 					--socket.transmit(socket.dport, socket.dhost, {
 					--  type = 'ACK',
 					--  seq = msg.seq,
diff --git a/sys/boot/opus.boot b/sys/boot/opus.boot
index 7ba7a1d..d139e37 100644
--- a/sys/boot/opus.boot
+++ b/sys/boot/opus.boot
@@ -11,7 +11,7 @@ for k,v in pairs(_ENV) do
 	sandboxEnv[k] = v
 end
 
-_G._debug = function() end
+_G._syslog = function() end
 
 local function makeEnv()
 	local env = setmetatable({ }, { __index = _G })
diff --git a/sys/kernel.lua b/sys/kernel.lua
index a787513..799164e 100644
--- a/sys/kernel.lua
+++ b/sys/kernel.lua
@@ -28,19 +28,13 @@ local focusedRoutineEvents = Util.transpose {
 	'paste', 'terminate',
 }
 
-_G._debug = function(pattern, ...)
+_G._syslog = function(pattern, ...)
 	local oldTerm = term.redirect(kernel.window)
 	kernel.window.scrollBottom()
 	Util.print(pattern, ...)
 	term.redirect(oldTerm)
 end
 
-if not _G.debug then -- don't clobber lua debugger
-	function _G.debug(...)
-		_G._debug(...)
-	end
-end
-
 -- any function that runs in a kernel hook does not run in
 -- a separate coroutine or have a window. an error in a hook
 -- function will crash the system.