If one would type on a computer on Shabbos would he be ovar an issur d'oraisa in regards to the malacha of writing? (The other malachos involved aside for a moment.)
Is there any room to say this would be an issur d'oraisa of casiva (כתיבה)? Perhaps there is a svara to say that since this a "derech" of writing nowadays that it gets the consideration that the Torah gave to a normal writing?
However, in reality there is no substance to this "writing" and no tangible thing to hold on to; it's simply how the computer screen is interpreting data. How can the malacha of casiva be extended to this?