Classic Mac OS had multitasking shoehorned into an operating system originally designed for single-tasking. This meant that if one program locked up, it would n

Classic Mac OS had multitasking shoehorned into an operating system originally designed for single-tasking. This meant that if one program locked up, it would never give up the processor and your whole system would lock up. The only way to recover was to hard power off the computer. It also meant that you couldn't do things as basic as listening to MP3s while web browsing, because whenever you loaded a new webpage your browser would hog the CPU to render the page so your MP3 player would skip.