Why the Original Macintosh Had a Screen Resolution of 512×324

Many classic Macs came with — or supported — displays running at 512×384 pixels, but many compact Macs, ranging from the original 1984 machine up through 1991’s Macintosh Classic II had built-in CRTs running at 512×342 pixels. That covers all black-and-white compact Macs with a 9-inch screen. The later Color Classic and Color Classic II used a 10-inch CRT at a full 512×384. This came up when I joined John Gruber on The Talk Show. At one point in the show, I rattled off the original Mac’s resolution as being 512×384. Except… it wasn’t. The original Mac screen ran at 512×342. I remembered the right number and corrected myself a moment later, but given the name of this website, it was pretty embarrassing. This set me off on a journey to understand why Apple made this decision. Why were the displays on early Macs 42 pixels shorter in height than later ones? After doing a lot of reading, there are several factors to consider when trying to answer this question. Memory The original Mac ... Read full article.