ComputerCraft

local monitor = peripheral.wrap('Change to side monitors on')
term.redirect( monitor )
monitor.setTextScale( <Change size> )
local w, h = term.getSize()
local function center(text)
    x, y = term.getCursorPos()
    term.setCursorPos((w/2)-#text/2, y)
    print(text)
end
center("Write text here")

term.restore()