c

rednet.open( "top" )

function sendToAll( message )
	for i=574, 577 do
		rednet.send( i, message )
	end
end

x = 0
y = 0

sendToAll( "_getSize" )
for i=1,4 do
	id, message = rednet.receive()
	if id >= 574 and id <= 577 then
		size = textutils.unserialize( message )

		x = x + size[1]
		y = y + size[2]
	else
		i = i-1
	end
end

function update()
	while true do
		os.pullEvent("redstone")
		if redstone.getInput("left") then
			sendToAll( "_update" )
		end
	end
end

function sshell()
	shell.run("shell")
end

term.clear()
term.setCursorPos(1,1)
print("Screen Size: ")
print(x .. " / " .. y)
print( string.rep( "-", term.getSize() -1 ) )
parallel.waitForAny( update, sshell )