The first RISC-V portable computer is now available

This is a common misconception. RVA22 is not just a bunch of profiles, but 2022's OS-A Platform.

Platforms do, among many things, require profiles, which are what you've described. In this particular case the RVA22 platform requires the RVA22 profiles.

From your link, documenting profiles, there's an entire section[0] addressing the difference.

The actual platform specification can be found here[1].

[0]: https://github.com/riscv/riscv-profiles/blob/main/profiles.a...

[1]: https://github.com/riscv/riscv-platform-specs/blob/main/risc...

They just open-source a light version of the C906, the OpenC906. For instance OpenC906 does not contain the vector extension.

But even the OpenC906 is only partially open-source. They only disclosed verilog code generated by an internal tool, so the real design source code is not open. Worse, they don't open source testbenchs which makes any modification or verification very tedious.

I've actually got an atom based PC that uses the exact same chassis and trackpad as the pinebook pro, and I've been trying to use the same community firmware. Because it is indeed horrible by default. Random touches, scrolling instead of pointing etc. No palm rekection at all.

Unfortunately I never managed to get it to install :(

This is like the classic home button on an iPhone being a tool for detaching the screen from the back of the phone.

They're still around but I haven't seen one since then.

So that leaves the last 3 links you provide.

#1: The screen is slightly tilted. So it isn't "flush with the keyboard" as I described. Also, this seems to have a typewriter-quality keyboard, which is the selling point there. I'm sure the users are touch-typists who are writing their novel, not someone trying to use BASH and VIM, which I'll have you note, is the target audience of this RISC-V computer.

#2: ...This is a keyboard. Which you connect to an external monitor. Sure, it has an internal monitor, but you can clearly see from the demo that it's meant for preferences and settings. You don't use it standalone. On-the-go seems to be a feature, but it isn't the focus, so it isn't a good example.

#3: ...This is a toy. This is a nostalgia talisman for people who want to go to a techno rave, or people who like the aesthetic of the Tandy 100. It isn't meant for practical use.

Not widely if that's what you meant by "in industry".

Most (like SiFive) did indeed wait for ratification (in case of last minute changes), before announcing their cores.

Pre-standard V chips do of course exist, and this is a good thing (there's better testing in using actual hardware implementations).

They have to use the opcode space reserved for custom extensions, and obviously cannot claim V compatibility. No overlap with actual V opcode space, and therefore no compatibility issues.

These are, nevertheless, fine for embedded uses in which the vendor has control over the whole stack.

It does also mean they have to take on the associated cost of having to maintain it, unless they choose not to actually use the custom extension at all, a choice that realistically will actually suffice for most deployments.

>I decided to install in my DevTerm the simplest module compatible with the popular RaspberryPi Linux distribution. It’s slower than the other “cores” but less power-hungry, and it’s very simple to install pre-compiled software and look up answers for any questions (as the RaspberryPi community is so huge). Yet this core still gives the user an ARM64-bit Quad-Core Cortex-A53 1.2 GHz CPU and 1 GB of RAM — more than enough to run simple writing apps.

But last year I learned about two innovations that have been brought to market that dramatically increase the potential abilities of such a device.

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It's entirely possible that your definition of 'any reasonable "work" performance level' is orders of magnitude higher than my "reasonably convenient programming environment". The VAX reference point is 1 Dhrystone MIPS, and the Macintosh SE (a 7.8 MHz 68000) was also about 1 Dhrystone MIPS. Current ARM7 Cortex designs deliver about 2 Dhrystone MIPS per MHz, so we're talking about 500kHz of ARM7 instructions here.

Without any fancy circuitry at all I was able to squeeze 8 mW out of a 38-mm-square solar panel from a dollar-store garden light, in direct sunlight. Theory predicts it should be capable of 200+ mW (16% efficiency, 1000 W/m²) so hopefully I can get better results out of other panels. The amorphous solar panels normally used on solar calculators, which work well indoors as well as in direct sunlight, are nominally about 10% efficient, which is to say, 10 mW/cm² in direct sunlight or 100 μW/cm² in office lighting. It's easy to imagine dedicating 30 cm² of surface area to solar panels, which would give you 300 mW outdoors or 3 mW indoors. (38 mm square is 14 cm². 30 cm² in medieval units is about 4⅝ square inches, depending on which inch you use.)

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So, what kind of computer can you run on a milliwatt or so?

Ambiq sells an ultra-low-power Cortex-M4F called Apollo3 Blue with 1MiB Flash plus 384 KiB RAM; the datasheet claims that, when fully active, at 3.3 volts, it uses 68 μA plus 10 μA per MHz running application code, and it runs at up to 48 MHz bursting to 96 MHz. So at, say, 10 MHz (20 VAXen or Macintosh SEs), it should use 170 μA or 550 μW. At 48 MHz (100 VAXen or Mac SEs), 550 μA or 1.8 mW. I haven't tested it yet. SparkFun sells a devboard for US$22 at https://www.sparkfun.com/products/15444.

Remembering, of course, that benchmarks are always pretty bogus, we can still roughly approximate this 20 DMIPS performance level as being roughly the processing speed of a 386/40, 486/25, or SPARC 2, and the 200 DMIPS peak as being roughly the processing speed of a Pentium Pro, PowerMac 7100, or SPARC 20 — but with enormously less RAM, an enormously lower-latency "disk", and a lower bandwidth budget for the disk. And no MMU, so no fork() and no demand-paged executables. You do get memory protection, hardware floating point, and saturating arithmetic, but no MMX-like SIMD instructions.

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If the computer's output isn't going to be just an earphone or something, though, you may need to spend substantial energy on a screen as well. Sharp makes a 400×240 "memory LCD" display (0.1 megapixels) used in, for example, Panic's Playdate handheld game console (https://youtu.be/uziFTK5c29k) which seems like it should enable submilliwatt personal computing; the datasheet says it uses 175 μW when being constantly updated with a worst-case update pattern at its maximum of 20 Hz. Adafruit sells a breakout board for the display for US$45: https://www.adafruit.com/product/4694

A VT100's character cell was 8×10 (https://sudonull.com/post/30508-Recreating-CRT-Fonts), so its 80×25 screen was 640×250, 0.16 megapixels, while the Macintosh SE was 512×342, 0.18 megapixels. Both of them were 1 bit deep: a pixel was either on or off. So two of these LCD screens together gives you more pixels than either of these two reference-point computers. However, the pixels are physically a lot smaller, which may compromise readability. (On the other hand, as you can see from the Playdate videos, you can do a lot of things on this display that a VT100 or Mac SE could never dream of doing because of lack of compute and RAM.)

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So, I think it's eminently feasible now, although it probably wasn't feasible ten years ago. But it's going to be a challenge; I can't just compile Linux and fire up Vim. Even if Linux could run on these super-low-power computers, they don't have enough memory to recompile it.

I agree that making computing power mobile makes it enormously more expensive, especially if you consider batteries unacceptable. But making computing power remote means that you need to spend energy on a radio to access it. That's a good tradeoff for some things, but not for others. In my other comment, note that if we believe Ambiq's datasheet, we can get the CPU speed of a SPARC 20 for 1.8 milliwatts.

It turns out the chip also includes a Bluetooth Low Energy 5 radio, so you can use it to remotely access more powerful stationary workstations via networking, as long as you're within a few meters of a base station. The radio costs 10 milliwatts when you're running it, six times as much as the Pentium-class CPU. Normal radios (Wi-Fi, cellphones) cost orders of magnitude more than that.

So constant remote wireless access to more powerful stationary workstations doesn't start to save energy until the amount of computation you're accessing is close to a gigaflop. Maybe closer to a teraflop if we're talking about streaming full-motion video. Intermittent remote access, of course, is a more reasonable proposition.

It's true that gaming commonly uses teraflops or petaflops of computing power, and plugging in such a beast in a server closet is a huge improvement over trying to somehow cram it into your pocket. But there are a lot of day-to-day things I do with a computer — recompiling my text editor, writing stupid comments on internet message boards, chatting on IRC, simulating an analog circuit, reading Wikipedia — that very much do not require gigaflops of computing power.

(Remote wired access of course can use very little power indeed, but if you're in a position to plug into a wire, you might as well deliver power over that wire too.)

If you take a modern cellphone and take almost all the processing power out of it, you still have a 1000-milliwatt radio and a 1000-milliwatt backlit screen. So you aren't going to get multiple days of battery life that way. 1000 milliwatts is enough to pay for dozens of gigaflops of computing power nowadays.

Myself, I have another reason: I travel, though I've traveled very little during the pandemic. But I am often someplace other than at home: at a café, in a park, at the office, in a bus, in the subway, in a taxi, visiting a friend in another city, at my in-laws' house, and so on. All of these places are out of Bluetooth range of my house. I could obtain internet bandwidth from a commercial provider, but that sacrifices privacy, it's never reliable, and I don't consider it reasonable to make my core exocortical functions dependent on the day-to-day vagaries of mere commerce. Personal autonomy is one of my core values.

I really hope not. The closest data center to me is about 70ms on a great day.

Most online games chose to host on servers that are 200-400ms away, it sucks immensely, so I don't play those games.

China has been effectively cut off from EUV steppers, but has used that fact to put a lot of money into developing their own by any means necessary. They have a pretty decent track record of developing manufacturing experience in something when they get cut off from importing it.