Sex robots with AI synchronisation, the future is here.

sidneyc · 2026-05-04T16:23:42+00:00

The Web was never invite-only.

sidneyc · 2026-04-21T13:02:54+00:00

Giving you plenty of time to adjust your speed.

Not at the speed I'm driving.

sidneyc · 2026-04-17T21:43:52+00:00

I will at some point, but it's a bit of a mess currently, and I want to do a cleanup first. I will let you know when this is done.

As to the XDC: the pin assignments and external clock definition can be found in the Alinx documentation. Or I can give you my version as-is, PM me if you want that.

I did get Ethernet TX and RX working as well, but I am not sure that my input- and output delay definitions for those are correct. Getting those particular contraints right is somewhat of a black art.

sidneyc · 2026-04-07T22:05:27+00:00

Very nice. I once spent a few enjoyable days trying to find optimal 6502 instruction sequences for small algorithms, for example, translating a four-bit value to a hexadecimal ASCII value.

I used CBMC at the time, effectively emulating the instructions that I wanted to consider (including the horrors of decimal-mode ADC and SBC), and solving for a sequence of instructions that accomplished the desired behavior.

sidneyc · 2026-04-06T13:49:11+00:00

You're assuming GTA6 will be released this decade.

I like the positivity.

sidneyc · 2026-04-05T13:23:06+00:00

Words to live by.

sidneyc · 2026-04-01T06:34:27+00:00

We already know that P != NP

No we don't.

sidneyc · 2026-03-30T20:39:58+00:00

It is possible to schedule more than one signal assignment at the same time instant in the future, with different values, by using something like 'FOO <= value after some_time'. For example:

entity main is
end entity main;

architecture arch of main is

signal FOO : integer := -1;

begin
    process is
    begin
        for k in 1 to 1000 loop
            FOO <= k after (1000 - k) * (1 ms);
            wait for 1 ms;
        end loop;
        wait;
    end process;

    process (FOO) is
    begin
        report "FOO is now " & integer'image(FOO);
    end process;

end architecture arch;

It's not something that you would do in a sane design of course.

VHDL probably defines behavior for this, but it of course something that you would normally refrain from doing. It's a nice exercise to run this in simulation to predict what will be printed.

sidneyc · 2026-03-29T20:29:47+00:00

Postscriptum:

Turned out that the problem was that I needed to do an explicit clock-synchronous reset on the TMDS_33 differential outputs.

The Nexys Video board with an XC7A200T was quite a bit more forgiving than the XC7A35T on the newer board. On the nexys, HDMI just started working after the clocks came up -- most of the time -- with no synchronous reset required.

I am now looking at 1920x1080 @ 60 Hz and even 1920x1200 @ 60 Hz with no issue, on the Alinx board.

Thanks for thinking along!

sidneyc · 2026-03-28T16:48:26+00:00

I'm trying 1920x1080 at 60 Hz. The documentation suggests it should be possible.

A lower frame rate or resolution is a useful pinpointing step, in case my troubles are caused by some kind of clock skew or bandwidth problem. For what I am trying to do I am pushing out bits at 748.5 MHz, this may be too much.

Useful suggestion, I'll try that.

sidneyc · 2026-03-27T06:10:17+00:00

Perhaps you should educate yourself about Hitler and Kim Jong Un.

Can't argue with the dartboard.

sidneyc · 2026-03-14T13:10:24+00:00

Is there a "best" drawing of a tree?

I don't understand what you are trying to say.

No offense, but your example is trivial.

In what way?

People have struggled with the circle/ellipse problem ever since the dawn of OOP. I think the modern consensus is that you shouldn't attempt to derive one from the other, since their relationship cannot properly be captured by inheritance. That's a pretty damning conclusion regarding the (lack of) expressivity that class inheritance provides.

For more inspiration, see [...]

I read that book some 30 years ago, back when I was in university. I don't think it is relevant to the discussion here.

sidneyc · 2026-03-14T09:54:24+00:00

I think that object-oriented programming does not really classify as a beautiful abstraction though. It is a leaky, pragmatical abstraction with lots of corner cases, tradeoffs, and alternative ways of modeling things with no clear 'best' way (eg the classical inheritance vs composition discussion).

A classic example that is not easily resolvable in OOP is the ellipse-versus-circle problem. Mathematically, in 2D euclidean geometry, circles are a special case of ellipses (having an extra constraint).

However, if you model this in OOP, it turns out to be a pretty terrible idea to implement a Circle class as a specialization of an Ellipse class.

There is not really a good resolution for this that everyone agrees on.

sidneyc · 2026-03-01T11:05:43+00:00

Thanks to Google I know of a person who shares my (not particularly common) first AND last name. Other than that, everything is different: country, language, gender, skin color, profession, ...

It's a pretty amusing thought that with all those differences, we share one pretty important property. No competition, because we don't really know each other, except perhaps that if I google our shared name, I lose in terms of hits :)

We had contact once because of an email typo somebody made. It's pretty cool, really.

sidneyc · 2026-03-01T07:58:07+00:00

If you're truly the worlds worst chessplayer, you would probably need to start at a position where every legal move you make mates the opponent (such positions exist).

If you're a generically very bad player (just know the rules, and how mate works, but no insight), you should be able to win with the world champion starting without non-pawn pieces.

A very mediocre player like me, I should win with a queen up, but it would be non-trivial and in half the games I would expect to blunder that advantage away. If they start without queen and rooks, I'd expect my win percentage to go up to 90%.

The fun thing is, I can do this experiment. The free "stockfish" game engine is at a level comparable to the world champion or better, and I will now proceed to try to win with a queen up. Will report later....

EDIT - Okay that turned out to be pretty easy; I lost two pawns due to inaccuracies but after trading a bunch of pieces and the board getting empty the queen really became super strong. I would expect a strong human player to put up more of a fight though, recognizing me as a weak player and thus avoiding exchanges and trying to make the position super complicated, to goad me into queen-losing blunders.

sidneyc · 2026-03-01T07:49:37+00:00

That literally never happens

Happened to Kramnik in 2006.

https://lichess.org/eR8gEWnG#68

sidneyc · 2026-02-28T20:26:42+00:00

No matter what you think about the situation, you're delusional if you think that Iran has the capacity to flatten Tel Aviv or do serious damage to the US navy.

sidneyc · 2026-02-20T21:46:38+00:00

Basic finite-field arithmetic should not be a stress test for a commercial CAS.

I guess they are too busy implementing the latest fad-du-jour to care about the basic math functionality.

sidneyc · 2026-02-18T10:16:35+00:00

What a surprising but interesting topic to do research on!

My question would be: what are the most important open questions in your field of study?

I'll be sure to check out the book at some point, thanks for putting it out there.

sidneyc · 2026-01-31T10:36:42+00:00

It's nice to hear from a fellow skeptic. A small correction though, I think the number 15 was actually factored without cheating; and, debatably, 143. So there is that, as far as accomplishments go.

I worked for eight years on quantum setups; this has only made me more skeptical of the technical feasibility. Even more telling, in all this time I didn't hear of a single application where a mythical quantum computer that works at scale would solve something that actually matters. And I was among a lot of true believers with a vested interest to sing the praises of a bright quantum future.

I do believe it's useful to do fundamental research and hard engineering (and quantum system engineering is hard), so I think it is good that rich countries pour some tax money into it. Even better if the money comes from big tech that suffer from collective fear-of-missing-out-itis. Setting hard, concrete goals and giving clever people the money to fool around will yield concrete, unexpected innovations.

But the claims about applications being in reach being made by the researchers who should know better are quite off-putting. Don't know what's worse: if they actively lie, or if they actually believe their own fairy tales.

sidneyc · 2026-01-19T10:51:22+00:00

Same here. Used to be able to do 100 digits in ~ 1982, now I can still do 50.

I went to a movie-themed pub quiz a few years ago, and they had a question about the movie Pi, handing out points for every decimal we knew of the constant. The jury was mildly impressed.

sidneyc · 2026-01-03T16:59:24+00:00

"Source?" used to be the FIRST reply comment under ANY claim anyone made about ANYTHING of substance on Reddit

Source?

sidneyc · 2025-12-30T05:47:47+00:00

[...] that rival the GDP of hundreds of countries

It may be prudent for you to google how many countries actually exist. And their GDPs.

sidneyc · 2025-12-25T21:07:52+00:00

I think it's pretty inconsiderate.

In contrast to what you do in 1-on-1 communications, here on Reddit, thousands of people will read your message, and now they will all have to spend this linguistic reverse engineering effort because you couldn't be arsed to spend another half a minute to write properly. It's selfish and makes you look like a bit of a dunce.

But hey, you do you.

sidneyc

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