Yes, you can put Graffiti 1 on a TX, the big snag is it breaks anything that puts a box on the screen for you to enter text in, such as web pages in Blazer. Using G2, if you enter more text that the box will hold, it pops up a text entry page, but if you try it with G1 then as soon as you fill the text box the TX crashes and resets itself.
It took me ages to find out that it was G1 that was causing all the blasted resets!! It's extra annoying cos I'm really coming to hate G2, with all its idiocies and general poor letter recognition...