[Xirdus]

There's a good chance it was Excel's workaround for some other GPU's buggy behavior.

[Taniwha]

there were no GPUs at that time. What we were building in the late 80s/early 90s were the first generation of Mac graphics accelerators, really just glorified blit engines, a class of things that eventually grew into what we now call GPUs as people started to push CPUs into them

[Xirdus]

I see. I took "early/mid 90s" literally and thought you mean like 1991 through 1995, inclusive.