cpmish

g/wiki/Ship_of_Theseus There was a code investigation that looked for any DR code in the early MS-DOS binaries: https://www.embedded.com/was-dos-copied-from-cp-m/ It concluded that no, code was not copied, but APIs were. https://www.researchgate.net/publication/309274064_Source_Co...

d, touchscreen, ARM based with multitasking GUI OS (later became Symbian, now FOSS.) Still ran for months on 2xAAs. CF cards for storage. Also in the same general category: Cambridge Computers Z88, Amstrad NC100/150/200. A4, no hinge, letterbox mono screen. Ran for days on 4 batteries. Silent typing. Full-sized keyboard, portable, silent and 100% solid-state when laptops were huge, expensive, slow and fragile. Multitasking OSes and many megs of RAM, on a Z80 CPU. 8-bit, but with a very basic GUI, end-user programmable in BBC BASIC. Expandable storage. These things should be possible today for say 25% of the cost of the cheapest possible Chromebook. Text-only GUI, no need for X.11 or Wayland or a pointing device. Underclock the CPU of a RasPi Zero or something for maximal battery life. Perhaps a good use for RISC-V. Maybe use an e-ink display. Make them very robust, with no moving parts, silent keyboards, maybe even waterproof. Ideal educational tools for kids. If phone network connectivity is a problem, don't do it. Make something cheaper and simpler than a tablet, with a hardware keyboard, that can be used away from mains power or the Internet for days not hours, and that runs a FOSS OS. Maybe make it powerful enough to run DOS apps under emulation: there are hundreds of legal freeware DOS apps out there for every function. People are enjoying running CP/M again on things like the NC200: https://www.z80cpu.eu/mirrors/www.dcast.vbox.co.uk/zcn.html And on VGA32 devices: https://www.instructables.com/Retro-CPM-Stand-Alone-Emulator... https://lehwalder.wordpress.com/2021/04/28/getting-runcpm-v5... But CP/M is very limited and it's not technically fully FOSS. https://github.com/davidgiven/cpmish DOS is. https://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/dis... There are loads of rich, powerful apps. https://clasqm.github.io/freedos-repo/Productivity.html

ams, here are some pointers if you wanted to write something yourself: Also written by the maintainer of the CP/Mish project (and not CP/M specific) is Cowgol. Alpha quality. But it's a self-hosted Pascal/Ada-like language with compiler. Runs on 8-bit systems, at least theoretically. It is written, of course, entirely in Cowgol: https://github.com/davidgiven/cowgol Millfork is another new language which targets CP/M systems, among others. It's a whole-program optimizing cross-compiler for a language somewhat lower level than C, with properties that make it very nice to compile for 8-bit systems like no recursion, and no automatic promotion to 16-bit integers in type handling: https://github.com/KarolS/millfork There's some work on a Z80 target for FreePascal. I don't think there's CP/M specific support, so there's a project idea: https://wiki.freepascal.org/Z80 SDCC supports the platform with C surprisingly well. I wouldn't call it rock-solid but compared to the above toys it is an industrial quality compiler for the Z80. In fact, C seems to be the most common actual language for hobbyist and the little remaining serious Z80 development, probably ahead of assembly. If it just reads and writes the terminal and can fit in about 60 KB, then a port is probably straightforward.