I’ve actually been wondering if it could be possible to design a small computer that powered off in between key presses (paired with an e-ink screen.) If the CPU state could be stored and reloaded in between key presses. I was mainly thinking about turn based games on an e-ink device, but I guess it could be suited to anything event driven that triggered the next set of CPU cycles to perform some work before a “sleep” instruction put the computer back into hibernation.
I did search online to see if anyone was thinking about something similar and there was a paper “Design of a nonvolatile-register-embedded RISC-V CPU with software-controlled data-retention and hardware-acceleration functions” which looked interesting.
https://www.sciencedirect.com/science/article/pii/S277306462...
Don't get me wrong. I like modern CPUs with huge caches and incredible power, but you do not need this for most devices. Also leads to lazy programming practices and calculators consuming hundreds of megabytes of RAM.
But you need a strategy to protect the screen which is the most delicate part of the entire assembly. They do sell screen protectors of various kinds and even supply one in the original box. I bought their magnetic case which works for my use case (I do not store it in a pocket with keys and other objects that might damage the screen).
You can use XIP to run code from Flash, so you can be get away with that in lieu of a decent amount of RAM.
The screens are really fragile, I've stuck my fingernail through three and broke one with an inadvertent tap from a screwdriver.
But they're only $10 and still work as a microcontroller.
Unless you're paying $40 for coffee and cake I'll call bullshit.
Also, kinda want to order a RP2350 board now too, but I know I'll probably end up having zero time to do anything with it and it'll just sit in a drawer somewhere...
That said, Photoshop doesn't feel like the sweet spot of what to run on this hardware. There's only 520kB of fast static RAM, and that's not enough to run a framebuffer with enough bit depth to hold a photo reasonably. I have invented a 4bpp compression scheme which opens up possibilities, but it's asymmetrical and in its current form compression is very slow, so it wouldn't be suitable for interactive work.
As a general matter, emulation makes a ton of sense. You can emulate all kinds of computers up to the late 80s, including video subsystems. Of course Mac and PC don't really do anything interesting like tiles and sprites, they're pretty much just dumb framebuffers.
I suppose in principle the RPi Pico could self-host its own OS and devel environment. 520 KB of RAM in the old days was plenty to fit an OS and compiler. No MMU so no paging though.
While the proposed use cases were things like that, I'd push back on saying that they weren't "intended to be general-purpose computers". I have the original 8080 manual in front of me, and it's very clear they considered them computers to be applied to problems (the first chapter is literally "The Functions of a Computer"). Oh, and the 8080 manual clearly identifies it as the "Intel 8080 Microcomputer Systems" and the 6800 calls it the "Benchmark Family for Microcomputer Systems"
In case anyone's wondering what makes HN so damn great
I spent pretty much all of the 1988-9 school year (I was 10) inhaling it.
Seriously, it was fantastic.
With two cheap PSRAM chips and a bit of trickery, you can upgrade that to 32(.5) MB, which is certainly enough to run a small OS.
In principle you can add even more memory with bank switching, but 32 MB is the limit for a flat address space.
The first Amigas had 512k of ram. Both had much less processing power.
With 32mb you could probably run some kind of Linux.
https://github.com/hchunhui/tiny386/tree/master https://www.cnx-software.com/2025/11/14/windows-95-made-to-r...
Imagine running an GPT-3 Generation model on a raspberry pi . This would be great
Because this is how I fake vectorized images in 2005 and it took dayyyyys