Yeah, the screen redraw stuff was tense.  As I recall, the best way to see that was on a mid-speed line, say 9600 baud.  Slower and you could see it but it was still just annoying.  A lot faster and there was no visible magic.  At 9600 you could see the screen optimization doing some startling stuff.
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On Mon, Apr 21, 2025 at 11:41 AM Lars Brinkhoff <lars@nocrew.org> wrote:
Mark Seiden writes:
> the display updating code, as i recall, had a skull and crossbones on it
> i remember there was a bit of a kerfuffle when richard stallman introduced
> that code into gnu emacs

This is true.  Gosling Emacs from 1984 and GNU Emacs 13 from 1985 both
have the skull and crossbones comment.