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Comment by tppiotrowski | Hacker News Reader

"Therefore, on the Lisa display there are 3 pixels in the horizontal dimension for every 2 pixels in the vertical. These different resolutions do compIicate, slightly, the design of the Lisa graphics soft- ware. For example, the software must remember that a graphical object 150 by 100 appears as a square, however 100 by 100 is a rectangle."

Glad this convention died. Definitely a "clever" hack to save memory bandwidth resulting in a lot of pain for future generations.

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It was a natural consequence of CRT displays being able to provide higher horizontal than vertical resolution. (If text would require higher vertical than horizontal resolution, we might have used CRTs rotated by 90 degrees.)

Only LCDs forced using a single fixed aspect ratio, which then was chosen to be the square one. (Though subpixel rendering still allows for higher horizontal resolution.)

Non-square pixel graphics systems were quite common back then.

The Mac really pioneered square pixels (at least for consumer machines). Reportedly, some wanted them for the Lisa, as well, but, as the Lisa was behind schedule and working perfectly with non-square pixels already, the Lisa was denied this luxury. (One may also argue that in an office environment the horizontal resolution may have been more important than square pixels, which would have come at the cost of a third of the horizontal resolution. As usual, no free lunch…)

The Corvus Concept beat it to market, had a higher resolution bitmapped screen with square pixels, was built on top of the same SVS Pascal compiler as Lisa, and vanished because it's software was primitive, barely using the capabilities of the screen and had softkeys like the HP Amigo and no mouse.

http://bitsavers.org/pdf/corvus/Corvus_Concept/

It's essentially what Lisa would have been if the UI direction hadn't changed because of Apple's exposure to the PARC Alto (which also had a 606x808 screen with square pixels).

Fun fact:

Mike Cook, the person who designed the Corvus Concept hardware, ended up going to Apple and designed the board for the LaserWriter II.

I didn't know the Corvus Concept, at all – thank you!

Skimming the user manual, there's a label window below the screen, very similar to the soft function keys approach of the early Lisa concepts, indeed.

Why is bitsaver's informative comment downvoted to dead? Yes slightly off topic re: pixel shape but relevant to the overall topic

They still happen. The official raspberry pi 7” lcd panel has non-square pixels. As do a number of third party small lcd panels commonly used with SBCs.

Fascinating. But how does the graphics card know the pixel layout of the display or is there a chip in the display that recomputes where to display a pixel at (3,3) for example?

WAP enabled phones (the early mobile internet protocol of the early 200s, using a card metaphor) tended to have elongated pixels as well. Converting images for this was fun!

(WAP used a special, binary image format, but the compiler for this didn't care about pixel ratio. The fun part was really designing and previewing these images on square-pixel hardware and then converting this to something which was still crisp on the actual hardware target. But then there were also PDAs, which did have square pixels…)

And you'd even get MS-DOS PC image editing and desktop publishing programs that didn't didn't correct for non-1:1 pixels on-screen, only (hopefully) when printed.

Yet another way the Mac was glorious at the time.

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