LokiOS: A new version of CP/M 2.2, written from scratch

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.

The other machine, the Loki, was to be an all-singing all-dancing games machine, and it never happened in any form. https://en.wikipedia.org/wiki/Loki_(computer)

It's like a windowed, multi-tasking environment where each process actually gets its own dedicated CPU/memory/display hardware and can run fully independent of the others.

CP/M was also very portable and eventually ended up on Atari ST 68000 machines which I also used with the GEM desktop/graphics environment. There was even a CP/M card for the Apple II that had a Z80 on it.

In contrast to CP/M. It requires a block device of some kind (i.e. a disk drive), and a console of some kind (typically, but not necessarily, a serial terminal).

While some applications did route around the BIOS and BDOS in CP/M, most did not. CP/M was quite portable across a crazy range of hardware. Porting a CP/M BIOS is a nice engineering and assembly language challenge for anyone willing to take it on, depending on their hardware environment.

Today, anyone with a Z80 chip, a RAM chip, and some paperclips to wire it all together can get a device that will run Wordstar. That flexibility makes CP/M very popular with retro enthusiasts today. It's easy to find dongle sized computers for $50 running CP/M on eBay. It's also easy to find full through hole kits of parts and PC boards to make your own. Or, grab a Z80 CPU and Peripheral manual, a copy of KiCad, some parts and breadboards and go to town. Having your creating run Wordstar beats blinking LEDs any day of the week.

It had terminal capabilities (not to the level of termcap in Unix, but good) which meant that shrinkwrapped software like Wordstar would run on anything with an 8080, Z80, or NEC V20/V30 and CP/M. The Osborne 1's tiny screen was only 50 characters wide instead of 80, but software still ran on it.

It hit the sweet spot of abstraction for its time, and made it easy to write drivers for custom hardware that a new manufacturer might decide to make.

Here in Europe I've never seen it in the real world. It was all commodore 64 and other 8-bit or early PC. Even in businesses.

As for the prevalence of its concepts, Gary Kildall borrowed a lot from minicomputer OSes that he was exposed to early in his career. CP/M brought a lot of the capabilities and styles of those $$$ systems to machines that people could use at home. So I think if you want to see where this style of CLI came from and why those things were popular you might look at DEC TOPS-10... or other "real" minicomputer operating systems that hobbyists coveted but could not afford for themselves.

Before standardization around the IBM PC, CP/M was the only way to get that, really. And there were boatloads of these 8080/Z80 systems out there, all sharing some common attributes but not being 100% compatible with each other, so CP/M is what glued them all together until the great wave of the IBM PC overtook them all.

It didn't have any. That's why it thrived. It was the first cross-platform OS for microcomputers. There were other microcomputers, but they didn't have OSes as such: they mostly had a BASIC interpreter in ROM and that was all.

And most machines had their own unique implementations of BASIC, all subtly different. In the American market (and only there), Microsoft BASIC was a lowest-common-denominator industry standard, because it was very small and MS made it cheap. It was rubbish, though: no graphics, no sound, no structure, not even IF...THEN...ELSE.

In the rest of the world, vendors competed for who could offer the best BASIC... and in the end, Acorn won, with BBC BASIC, which was the best by far of any early 1980s micro. Acorn went on to invent the ARM processor.

However, all the different BASICs made all the machines software incompatible.

CP/M was a DOS: a disk operating system. You needed a disk drive, and ideally 2. That was expensive, so CP/M ran on expensive micros in the small-business market: often they cost thousands of £/$ while home computers sold for hundreds of £/$.

In that space, CP/M had no competition until MS-DOS came along, for the newer and more powerful 16-bit Intel 8088 and 8086 chips.

Microsoft's first hardware product, the Z80 Softcard for the Apple II, was a bestselling product because it gave the Apple an 80 column display and CP/M 2.2 all in one package.

B: it’s possible, even recommended, to express disappointment and talk about the virtues of the original design without saying this “sucks”

Very embarrassing, but I could not move to Sweden, because unsolved tax issues from 1975.