f0nt

local list = "abcdefghigklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
local new = "4bcd3fgh1gklmn0pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

local oldw = term.write
function term.write(txt)
    for i = 1, #txt do
        local tow = string.sub(txt, i, i)
        for r = 1, #list do
            if string.sub(list, r, r) == tow then
                tow = string.sub(new, r, r)
            end
        end
        oldw(tow)
    end
end