Re: Not all micros
[Author here]
> I really don't understand what Liam is trying to say here.
That's OK. This article was carved out from a modest part of a talk I delivered 6Y ago. I had to cut probably over 50%. What remains is incomplete, but I hope to return to it.
> The vast majority of "every computer in the world" are embedded systems.
[...]
> While a great many of those use CPU cores descended from families popularized by microcomputers, they're not "micros" in any useful sense, since the whole point of the microcomputer was to be user-interactive.
[...]
> At the other end of the scale, we still most definitely have mainframes, which are in no way "micros". Not at all. And we have supercomputers, which also aren't "micros" under any sensible definition — not even "at heart", not even if they use Intel or AMD CPUs. And we have China building Longsoon-based MIPS-derived supers, while there's never been a MIPS-based micro. Yes, SGI sold MIPS-based workstations, and those were often primarily single-user machines, but they were not in any useful sense microcomputers.
OK, look, if you are going to argue over definitions, then we have to start with agreeing what we are trying to define and what words we are defining them in.
So, step 1: let us approach this problem from 2 different angles and see if we can enclose it.
In biology, in taxonomics, there are two types of analysis and people doing it: "clumpers" and "splitters".
Splitters want to subdivided clades, groups, by their differences. Clumpers seek to group them by their similarities.
Let's try both.
From there... step 2: the "clumper" approach. Lines of descent.
Is an embedded system a computer? Is a washing machine with a microchip a computer? I'd say no.
Is its embedded controller a computer? Maybe. Probably no. Is it a general purpose machine used by a human to run programs? No. Is it reprogrammable? No. Is it general purpose? No. Is it interactive? Itself, with humans? No.
So, it's not a computer and we can ignore it.
*But* is it derived from and closely enough related to conventional general-purpose interactive computers that it can run software developed and tested on them? Is it a generic CPU design running a generic OS?
In many cases, yes.
Then while it may not itself be "a compurer" in any recognisable sense, then it's descended from and closely related to things that *are* computers, and if those are micros, then it's a micro.
Step 3: the "splitter" approach:
There were, historically, 3 types of computer: (a) mainframes, (b) minicomputers, & (c) microcomputers.
[a]
Mainframes are room sized, cost millions, and were primarily batch oriented, not interactive. (That was bolted on later.)
I doubt any embedded systems are based on mainframe designs. I welcome correction. They are not mainframes.
[b]
Minicomputers are extinct. (Some software survives.) Minicomputers were inherently multiuser, inherently interactive, desk-side in scale, shared by departments. They did not have their own keyboards or displays: they were driven from terminals.
This category of machine is extinct, but the designs of their OSes dominate all computing today.
[c]
Microcomputers. Driven by a single-chip processor, designed to be used by a single person. Generally inherently single-tasking.
They are everywhere, but their OSes are today mostly based on minicomputer OSes. But the OSes are, mostly, compatible with earlier OS designs, even if that is disappearing.
64-bit Windows can't run DOS apps, but 32-bit Windows can, and 32-bit Windows is intercompatible with 64-bit. It's the same family, same UI, same filesystem, etc. It is recognisably a DOS descendant.
It's a micro OS even if its design owes much to VMS, a mini OS.
Windows PCs are microcomputers.
Does your notional embedded chip run Windows? Then it's a micro. Does it use a micro architecture, from Z80 to 8086 to MIPS? Then it's a micro.
Mainframes are still around. They are still binary compatible with 1960s kit. They are still mainframes. End of discussion.
Supercomputers built from clusters of microcomputers are built from microcomputers therefore they are microcomputers.
Any single user general-purpose PC, be it Arm or MIPS or whatever, is a microcomputer built from tech that evolved from microcomputers.
Therefore they are microcomputers.