> It can’t be understated how much impact Wolfenstein 3D and Doom had. Commander Keen was already quite the tech demo, with scrolling on a PC without dedicated

> It can’t be understated how much impact Wolfenstein 3D and Doom had. Commander Keen was already quite the tech demo, with scrolling on a PC without dedicated hardware But ... the PC did have hardware supported scrolling? CGA, EGA, VGA and the various SVGAs all had a register for "address of beginning of screen". It was not well documented, and nontrivial to use especially because of the banked memory setup -- but it WAS there even on the first ever CGA, Hercules and Monochrome adapter which were all based on the 6845 - and also available on EGA, VGA etc - the latter made things even less usable by practically requiring Mode-X plane memory addressing to use. And IIRC, that's what commander keen had used. [0] https://en.wikipedia.org/wiki/Motorola_6845#Tricks https://en.wikipedia.org/wiki/Motorola_6845#Tricks