Hardware terminals had this feature, ish. The vt220 had a 'slow scroll' speed which would buffer text and scroll it at a viewable speed, limited by the quite s

Hardware terminals had this feature, ish. The vt220 had a 'slow scroll' speed which would buffer text and scroll it at a viewable speed, limited by the quite small memory on the screen. It also had a 'pause' key which would pause the display and then continue the output (again limited by the terminal's memory). See also PC 'scroll lock' key.