This is not a bug. At any point in time, there is a character position associated with the upper left corner of the text window. Text before that position is not shown; text at or after that position is shown, until it runs off the bottom of the window. Let's call that upper left character position p0.
Most of the time, acme/sam/rio work to arrange that p0 follows a newline character, so that the window begins at the beginning of a line. Sometimes this is not possible. One case is when a line is very long--longer than the entire window--and you want to see the end of it. Another case is when you tell acme/sam/rio to scroll past the end of the text. Then p0 is the end of the text, right where your cursor is. When you type new text, it correctly shows at p0. The prompt is still there, just off the window to the top. You are expecting line-oriented behavior in a "stream of bytes" world. Russ
