@erikarn @mjg59 Only sort-of true - it does mention that on an actual 8088 you'd sit there watching the windows repaint quite slowly - the emulator it's running in is many many times faster than the actual hardware would have been. The 68000 in the original Mac is several times faster than the 8088, and large chunks of the OS were stored in ROM, so didn't have to be kept in RAM or reloaded from floppy.