Some thoughts: - The banal answer is yes we can use the same components and build the same style of machines. - A slightly more nuanced answer is that we have

Some thoughts: - The banal answer is yes we can use the same components and build the same style of machines. - A slightly more nuanced answer is that we have much more efficient components these days, from CPUs to displays. So we could do better now for the same functionality. - Adding a nice display, wifi, bluetooth, etc should be possible for a small display. For reference, the apple watch has a battery capacity between 250mAh and 550mAh. A single alkaline AA battery has over 3000mAh. - Eink displays have some tradeoffs but are very low power and are getting better at display update times. - OLED displays can be quite power efficient. Especially the monochrome ones. But of course there isn't really a market for this style of device anymore with smartphones dominating.