I'd just like to add, that I don't think it's writing as fonts, like runes. Tiompan is right, this style of writing was much later 1500bc?
I think they have a different interpretation ability within them.
Well I have to admit I know very little about this sort of thing, but it's very interesting. It reminds me a bit of the difference between western characters and Chinese characters (although maybe this analogy isn't quite right).
Are there any good photos about of the original inscriptions that were found on the grooved ware? I'd like to see that.