[reerdna]

Thank you! Yes, I've had this in mind for a while, I have some pictures of beginning the first prototyping by dismembering the keyboard back in 2020, although what I was thinking at the time is not recorded.

I would not be surprised if it's simply the availability of the good-enough CPU that caused the idea to take root in multiple heads independently.

initrd has gathered a lot of resources in https://hackaday.io/project/177716-the-libre-autarkic-laptop and https://github.com/EI2030, he sent me a link to your writing a while back and it made me think of using an sd card for storage, which I had previously rejected for taking too much power. But I have since managed to only power it when reading/writing files and it works quite well.

[kragen]

I didn't learn about the CPU or the display until 02021, but apparently they've been around for quite a number of years. My notes in energy-autonomous-computing in Dernocua http://canonical.org/~kragen/dernocua/ on both the Ambiq chips and the memory LCDs date from July 02021, also three days apart.

For the Zorzpad's main nonvolatile storage my plan is to use bare SLC NAND Flash, but I'll have to write to it fairly slowly to get to my desired design lifetime. So my initial plan of a KeyKOS-like or EUMEL-like transparently persistent system with huge virtual memory is out the window.

If your limit is only the power budget, though, that approach seems like it might be within reach; the energy-autonomous-computing note I mentioned above has a table of memory types and their energy consumption, and if I didn't fuck up the calculations, NAND Flash only costs about 10 nJ per byte to write. So a full memory snapshot (384 KiB) every 30 seconds (104 kbps) would only cost about 130 μW, and if your Lisp (or other virtual machine) can keep track of what data is dirty, it should be a fraction of that.

I'm glad to hear my notes have already been useful to you! I'm sure yours will be for me, too. And thanks for the links to initrd's work! I somehow didn't know about it.