hi guys as i know we have gui and non gui application today. but remember back in the old days there were many application thats kinda like half gui half not . the applications are text based and it has no GUI like what we have now if we were to use java swing library or etc. but you could pretty much select the area that you want using keyboard shortcut . pretty much looks like vim with more features. basically it is text based but not fully gui so my question is how did they do this ? to make the text output persistent and process the data as being inputed non sequentially (non gui typically inputs data non sequentially)