Why the original Macintosh had a screen resolution of 512×324
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Re: Why the original Macintosh had a screen resolution of 512×324
#2The title is incorrect, because b&w Macs have 512×342 resolution, not 512x324.
It wouldn't've been too crazy had Apple went with 64K x 4 chips, so they'd've just needed four of them to get 128 KB at a full 16 bits wide.
512x342 was 16.7% of 128 KB of memory, as opposed to 18.75% with 512x384. Not much of a difference. But having square pixels is nice.
Re: Why the original Macintosh had a screen resolution of 512×324
#3The article really didn’t explain why they picked that number.
Re: Why the original Macintosh had a screen resolution of 512×324
#4The title is incorrect, because b&w Macs have 512×342 resolution, not 512x324. It wouldn't've been too crazy had Apple went with 64K x 4 chips, so they'd've just needed four of them to get 128 KB at a full 16 bits wide. 512x342 was 16.7% of 128 KB of memory, as opposed to 18.75% with 512x384. Not much of a difference. But having square pixels is nice.
It looks like it's just the HN submitted title which is wrong (currently "Why the Original Macintosh Had a Screen Resolution of 512×324"). The article's title is "Why the Original Macintosh Had a Screen Resolution of 512×342", and "324" doesn't appear anywhere on the page.
Re: Why the original Macintosh had a screen resolution of 512×324
#5The article really didn’t explain why they picked that number.
For efficient graphics routines on a 32 bit machine, it's important that the scan line direction (aka horizontal for normally mounted CRT's) be a factor of 32, preferably one that's a power of 2.
The article mentions the desire for square pixels. So presumably they chose the horizontal resolution first and then chose the vertical resolution that gave them square pixels for a 512 pixel horizontal resolution.
Re: Why the original Macintosh had a screen resolution of 512×324
#6The article really didn’t explain why they picked that number.
The article says:
In short, there’s no easy answer to explain why early compact Macs ran at a screen resolution of 512×342. Rather, Apple was doing what it does best: designing a product with the right trade-offs for performance, ease of use, and cost.
Re: Why the original Macintosh had a screen resolution of 512×324
#7The answer is probably more akin to: "As small of a resolution as they could make it without Steve bitching at them about it."
Re: Why the original Macintosh had a screen resolution of 512×324
#8The title is incorrect, because b&w Macs have 512×342 resolution, not 512x324. It wouldn't've been too crazy had Apple went with 64K x 4 chips, so they'd've just needed four of them to get 128 KB at a full 16 bits wide. 512x342 was 16.7% of 128 KB of memory, as opposed to 18.75% with 512x384. Not much of a difference. But having square pixels is nice.
It looks like it's just the HN submitted title which is wrong (currently "Why the Original Macintosh Had a Screen Resolution of 512×324"). The article's title is "Why the Original Macintosh Had a Screen Resolution of 512×342", and "324" doesn't appear anywhere on the page.
Looks like someone is reading Hacker News comments and editing the page - archive.org captured the page probably mid-edit, and it says "324" in one place: https://web.archive.org/web/20250527202300/https://512pixels...
Re: Why the original Macintosh had a screen resolution of 512×324
#9The article really didn’t explain why they picked that number.
The article says: In short, there’s no easy answer to explain why early compact Macs ran at a screen resolution of 512×342. Rather, Apple was doing what it does best: designing a product with the right trade-offs for performance, ease of use, and cost.
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Re: Why the original Macintosh had a screen resolution of 512×324
#10The article really didn’t explain why they picked that number.
I don't know, but I can do some numerology: a 3:2 aspect ratio that's 512 pixels wide would need a 341 and a third lines, so round up and you get 512 by 342.
The later 384 number corresponds to an exact 4:3 aspect ratio.