The old processors are commonly underestimated. I remember the times of the first versions of Turbo Pascal on CP/M and 8086. It had a very basic user interface (just key strokes) but the language was very convenient, and compilation was incredibly fast, almost instant.
I also had an Atari ST with 8MHz 68000 (no math copro) with Tempus Editor (ASCII) and Tempus Word (word procesor). Both were written in assembler, also incredibly fast -- faster than MS Word on a PC today. Other people used their Atari ST to write their disseration with Signum, and others published professional newspapers with it.
What does a PC really need? A convenient assembler, a few compilers, a screen editor (vi), a simple database, a word processor (TeX), simple TCP/IP and other very basic things. Just the things which Alan focuses on. Unix on a Z80 or on enhanced FPGA cores sounds really interesting.
I am a happy Linux user for decades but I am seriously concerned about the future of Linux. On one hand Linux will probably soon be kept out from hard locked UEFI/Secure Boot systems, on the other hand modern PCs cannot be trusted anymore in case of security anyway. Also many Linux distros follow the questionable systemd way which makes me wonder if Linux will soon be bloated up like Windows. The Linux kernel runs wonderful so far but it already has several million lines of code, and systemd will add a significant level of complexity.
These things are reasons why I consider Alan's approach of "back to the roots" the right way and very promising. Not only the software is open source but also the requirements for the hardware are so low that many people could build their own System V Unix Z80 systems at home. Cheap microcontrollers like the Parallax Propeller could be added to provide VGA output and parallel I/O.
I wrote 2 games on the Gameboy and Gameboy Color assembly (both running Z80s at 4 and 8 MHz) back in the day and they were great to program on. Loved the simplicity of the machine.
