I find this project very intriguing (besides the fact that, despite being, or at least having been, a big Sir Clive fan, I had never heard of "project Loki").
However, it's disappointing that the author didn't publish its source code.
Really?! Wow. It was very famous in the Sinclair community of the time. The last new computers from Sinclair Research were the QL (a 680xx home computer launched two weeks before the Mac) and the Spectrum 128, which used a design partly from Investronica in Spain, which tragically didn't incorporate the improvements from Timex in the USA -- it didn't have the extra graphics modes, which the Spectrum desperately needed, and it didn't have joystick ports or a cartridge slot. (Those appeared in the ZX Interface 2, of course.)
The two planned machines that Sinclair was talking about were the Pandora and Loki.
Pandora was to be a Z80-based laptop -- and bear in mind, at this time, laptops did not really exist yet. Sir Clive's second computer company did launch a derivative of this idea: the Cambridge Computers Z88. I have one. It's a lovely machine, hindered by nonstandard storage slots (because the standards didn't exist yet), and an awkward way of getting documents off the machine: RS-232 serial.
(The better way, IMHO, is what Alphasmart did later: make the portable appear as a keyboard, so it can just type your documents into any computer with the right keyboard port, whatever OS or apps you are running.)
The Z88 does show that Sinclair learned from his mistakes: it has its own proprietary OS, OZ, which is still in development -- a new version, 5.0, is in beta.
https://cambridgez88.jira.com/wiki/spaces/OZ/overview
But on top of OZ it runs the standard Z80 edition of BBC BASIC.
As an aside, I gather than CP/M+ (aka CP/M 3.0) runs quite well on the Spectrum Next and is due to be available on the Spectrum Next Issue 2 (whenever they get hold of the FPGAs the project is hung up on). And the Next looks a whole lot like Loki, except with a gonzo modern FPGA pretending to be a really fast Z80, SD card support, and a Raspberry Pi Zero as a GPU(!). It even costs about the same as an original Spectrum 16K did in 1982, adjusted for 40 years of inflation.
the QL (a 680xx home computer launched two weeks before the Mac)
This implies that the QL was a competitor to the Mac. My sincere apologies if that wasn't your intention, but anyone who has used a QL and a Mac would have a hearty chuckle at the thought.
Sinclair guessed and gambled on the next big thing in small business micros being multitasking. It wasn't. That came more than a decade later. The next big thing, we know now, was the GUI.
Also, the QL was far too savagely cost-cut, as was Sinclair's wont.
But what is rarely considered is that the QL inspired more derivative designs than almost any other micro except the IBM PC... if you exclude the dozens of illegal Sinclair Spectrum clones in the Soviet Bloc.
The Thor, Thor II, Thor III. The Aurora. The QXL card. The Q40 and Q60, and later, and still around now, the Q68.
The OS was rewritten as SMSQ/E and was sold in a form that ran on Atari ST hardware, too.
And the many that didn't run QDOS: the Merlin Tonto, ICL OnePerDesk, Telecom Australia Computerphone.
About a dozen different computers from half a dozen companies, all QL compatible to some degree, developed and sold over some 35 years, is pretty impressive, IMHO, for a machine widely seen as a flop and a failure.
I had a Z88 back in the early 90s. A great little machine. I still think Pipedream is one of the ideal pieces of productivity software. The Alphasmart was a gem as well.
However, it's disappointing that the author didn't publish its source code.