The MOS 6581 SID, the original version of the sound chip in the Commodore 64, was according to Wikipedia, 'produced in 7-micrometer technology to gain a high yield; the state of the art at the time was 6-micrometer technologies.'
At that process size, area was a limiting factor, though not much of one; the chip didn't end up with every feature Bob Yannes wanted, but a Commodore manager famously pointed out to him, with only a little hyperbole, that the chip was ten times better than anything else out there, and twenty times better than it needed to be.
What was the actual die size?