MacOS System 7 looks like it would be a nice native interface for an e-paper tablet. I never used a Newton.
I’ve thought for some time now that if one were build a System 7.5/Mac OS 8 laptop with an e-ink or high quality transflective display (like that found on the Playdate[0]) and new 68k/PPC SoC built on a modern node with a modern battery, the resulting device would be surprisingly useful even if lacked connectivity. It’d sip power, with battery life likely measured in weeks or months and could probably be kept charged with a lid-sized solar panel.
[0]: https://play.date/
Are you sure? I think Classic MacOS effectively always busy-looped (WaitNextEvent would block, but only if the OS could run another event loop), never sleeping its (single) CPU.
https://developer.apple.com/library/archive/documentation/ma...:
“The Event Manager reports a null event when your application requests an event and your application’s event stream does not contain any of the requested event types”
If that’s true, that modern node CPU would not sleep most of the time, but just loop a lot faster.
Knowing this limitation though, I created created a kind of eInk calendar instead - as a love letter to my Mac Plus from the 90's.
Video of an Onyx BOOX Note displaying video, which I can vouch for from a similar (Max Lumi) device:
<https://yewtu.be/watch?v=XRDJv_-wWBI>
For a relatively static GUI display (such as the Classic Mac), e-ink displays are in fact viable, and there are e-ink devices sold specifically as computer monitors:
<https://shop.boox.com/products/mira>
For a demonstration of the capabilities of various e-ink displays (least capable are first), see: <https://yewtu.be/watch?v=KdrMjnYAap4>
I'd want a B&W, line- or halftone-oriented graphics, and relatively static window placement in general, with paginated rather than scroll-based displays (that is, content updates a full screen at a time rather than scrolling). It's not that scrolling isn't possible, it's just that it's really annoying. And there's a reason e-ink devices tend to use line drawings or etchings as demo / sleep screens (see Diaspora* post below for example).
I've written numerous times on HN about what the benefits and affordances of e-ink are, e.g.:
<https://news.ycombinator.com/item?id=31396797>
<https://diaspora.glasswings.com/posts/638a8d10e041013afba844...>
In which case, higher display quality (more pixels, sharper boundaries, deeper blacks, whiter whites, and less ghosting) tends to come with slower display response.
When you're reading static text, page-by-page, that's an acceptable trade-off. If you want to scroll, zoom, or pan through content, or are looking at animations or video, you'll want lower definition & sharpness but higher refresh.
And remember that once an image is displayed, it will persist indefinitely without further power to the display.
Newton can be emulated on your iPhone or iPad using an app called Einstein, but you'll need a stylus as the interface elements are tiny and require a great deal of precision.
The terms "e-paper" or "electronic paper" tends to be a generic label usually applied to electrophoretic displays, though there are numerous other technologies (Gyricon, electrowetting, interferometry, plasmonics).
E-Ink[tm] is a specific technology and trademark owned by E-Ink Corporation, covered by numerous patents, and to date has relied on electrophoretics.
I've addressed display characteristics in another comment to this thread here: <https://news.ycombinator.com/item?id=39198053>.
I can assure you that if e-ink characteristics and strengths are addressed by UI/UX design, e-ink can be quite satisfactory and is often preferable to other display options.