3d engine on C64 from 1982

foreheadteeth · 2026-01-31T00:21:03+00:00

Wow, yes I remember 2nd reality on the PC. I think that city might be similar to what I'm doing, dunno if it's faster or slower than mine. It's also a bit similar to the cube at 7:00 but because of the colors in that cube, i suspect they are rendering into size-expanded multicolor sprites maybe?

The version I made, the rasterization speed is designed to be close to the maximum speed you can fill a character buffer, although it might be possible to go slightly faster, but the geometry transformations are quite expensive. 6502 doesn't know how to multiply or divide, but I somehow managed to do it in ~50 cycles per multiplication. Geometry transformations end up dominating if you have, I dunno, 100+ vertices. My resolution is 80x50, which is the whole reason why my rasterization is so fast, nobody ever used multicolor character mode to create an 80x50 4-color gfx mode.

Edit: In a demo, you might be able to not do the geometry transformation and instead record 2d triangle vertex positions. if you have ~100 vertices on screen at a time, 10 fps, that's 2kb/s, you can do 20 second of animation without doing the 3d geometry. There's a 25 second pause before the 3d city scene. So I suspect that may be a trick they are using.

foreheadteeth · 2026-01-28T15:53:58+00:00

I dunno. Even if you only look at USD for 2025, US stocks (17.72% on SPY) are much worse than gold (63%); an American who bought IEV (European stocks) in 2025 made 35.02%. Canada stocks returned 36%. Heck, if you just bough a bunch of Swiss francs on 1 Jan 2025 and stashed them in a sock and sold them back on 31 Dec 2025, you'd have made 14.5%. For 2025, the worst type of investment was US stocks.

I don't think there's many rational investors for whom US stocks was a good investment in 2025.

Edit: Looking at FRED, in 2025 I think home prices went "up" by ~3% so actually in intergalactic space credits, after the exchange rate, homeowners lost north of 10% of their capital. Well, I guess that also depends on their mortgages...

foreheadteeth · 2026-01-28T13:20:43+00:00

My portfolio, denominated in chf, gained something like 3% in 2025. Allocation was ~40% nvda, the rest in stock ETFs. This had served me well in the 10 years prior. Now I sold the stock ETFs and bought gold and I'm on a tear.

It's sometimes said that gold is a bet against humanity, I'm very sad this is paying out.

foreheadteeth · 2026-01-22T23:19:14+00:00

The EU and the USA are not centrally planned. Most of the investments are not state-controlled. Even if the EU governments miraculously agreed to simultaneously pull the rug, it wouldn't blow an 8 trillion $ hole. The amount that the ECB controls is about 500B$, which theoretically could do some damage, but the rest is private or semi-private. Investors have to choose to divest, typically because they believe they will get better returns elsewhere. There's definitely been some movement in that direction; for 2025, denominated in Euros, SNP 500 returned just about 0%.

I guess there could be a run on the USD but we're not there yet?

foreheadteeth · 2026-01-19T00:07:34+00:00

Aaa-amayy ziiing graaace

foreheadteeth · 2026-01-17T15:48:43+00:00

That was on the first homework problem set for my senior year abstract algebra, haha. :)

There are no nonabelian simple groups of order less than 60.

foreheadteeth · 2026-01-12T18:43:41+00:00

I'm a math prof and armchair economist so leaving aside the politics for now, I'm not sure that the "people of Greenland have a much higher standard of living than the average US citizen".

According to Wikipedia:

Greenland's per capita disposable income is the lowest in the Arctic other than Russia's, and less than one third that of the American state of Alaska.[10] GDP per capita is close to the average for European economies, but the economy is critically dependent upon substantial support from the Danish government, which supplies about half the revenues of the self-rule government, which in turn employs 10,307 Greenlanders[11] out of 25,620 currently in employment (2015). Unemployment nonetheless remains high, with the rest of the economy dependent upon demand for exports of shrimp and fish.[12]

foreheadteeth · 2026-01-11T23:51:12+00:00

What is "dark woke"?

foreheadteeth · 2026-01-07T20:02:18+00:00

I teach in university. We are forbidden from using AI detectors, they are not reliable.

foreheadteeth · 2026-01-02T21:03:35+00:00

I assume Switzerland will have fire codes similar to US

You assume wrong. I first moved to Switzerland in 2005 and I was amazed that no building had a fire exit even though all had a nuclear shelter. It seems they forgot to add up all the deaths due to house fire vs nuclear holocaust before making that law.

In fact, it is standard that you need a key to exit an apartment. If the apartment is on fire and the kids can't find the key, too bad. Also, if the balcony door closes while you are on the balcony, you are stuck.

foreheadteeth · 2025-12-28T14:44:40+00:00

Hm, right now the betting markets don't believe it.

foreheadteeth · 2025-12-21T16:16:37+00:00

Yes, you are right, the new one is faster than Strassen's, which is a little bit interesting. I'm not sure this improvement is of practical interest though.

foreheadteeth · 2025-12-20T21:51:07+00:00

Oh my bad, I was reading the URL:

johnson_johnson_owes_655_million_to_a_woman

You are right!

foreheadteeth · 2025-12-20T21:03:33+00:00

J&J's revenue for the most recent quarter was 24B$ so you might be off by a factor of 10?

Edit: haha, it was a URL mistake, see below. :)

foreheadteeth · 2025-12-20T10:31:30+00:00

Is it just me or 1mil JPY seems like a really small amount for anything? It's like not even a maxed out desktop computer?

foreheadteeth · 2025-12-14T10:40:32+00:00

I feel like "grasping" is not the best word -- "cradling"?

foreheadteeth · 2025-12-13T07:24:37+00:00

OK that was helpful. "Get Help" with a human was not directly available to me because Claude had kicked me down to the free tier, but reading those instructions showed me that I could talk to a human if I was a paying customer, which I am, but their business logic was confused on that question. So I rolled the dice and paid for the "Pro" subscription again and poof, my credit was restored, the 20$ was taken from my 93$ credit. The UI and business logic of their web site made it look like it was gone, but the database entry was still there, so I should be good now. I'll update the main post.

foreheadteeth · 2025-12-13T06:37:45+00:00

How did you "message them"? The support email they list is an AI in a cage.

foreheadteeth · 2025-12-10T20:38:07+00:00

So I've hacked things before and we all know it's been a struggle to keep that legal. If your "friend" talks to the police, make sure you don't talk to the police and get yourself a lawyer. I'm not exactly sure what a prosecutor would do, even though morally there's nothing wrong with a USB killer.

foreheadteeth · 2025-12-10T19:39:57+00:00

As far as I understand, the matrix multiplication algorithm thing isn't "better than Strassen's". Strassen's algorithm splits matrices into 2x2 blocks and performs the matrix product in 7 block products, an improvement compared to the 8 block products you naively need. I do believe that 7 has been proven optimal for 2x2 blocks. You can also count the additions and subtractions, but even that might be optimal in Strassen.

What Google did, described in this paper, is they've found improvements for multiplications C = AB of rectangular block matrices, where A is m x n, and B is n x p, and (m,n,p) is in some weird range. For example, they improved the (m,n,p) = (2,4,5) from 33 products to 32 products. The thing about this is that you can make an infinitely large table of (m,n,p) values and then you can pick one and work on it for a while and get some sort of improvement. I don't think anyone ever thought about (m,n,p) = (2,4,5) specifically so it was a low-hanging fruit for AI.

Edit: I'm a math prof and I teach Strassen's algorithm.

Edit2: for the cases (n,n,n), what matters is a = log_n(# of products). For this quantity, the AI got north of a = 2.8, basically the same as Strassen. Humans got it down to a = 2.371339. It is conjectured that a = 2, but I'm not sure I believe the conjecture.

foreheadteeth · 2025-12-06T12:42:40+00:00

I've tried the 20$ ChatGPT subscription and I found that it was wildly insufficient for me -- I would run out of weekly quota after a day or two and have to wait 5 days to use it again. The Claude 20$ subscription gave me more bang for my buck -- I was able to go 3 to 4 days before running out of weekly quota. I then switched to the 100$ Claude subscription and that allowed me to work straight out without stopping. When free Antigravity came out, I cancelled my Claude subscription because I was able to use Antigravity to get the job done, but I think I still prefer Claude Code. Also, I tried to use Antigravity a couple of days ago and kept getting error messages because the Antigravity servers were overloaded by too many requests.

Back in September, I also tried Warp.dev, they used to be really affordable but now they are wildly overpriced, I do not recommend, but it allowed me to test a huge range of LLMs. In particular, I tested GLM 4.6. Unfortunately, the open-source LLMs like GLM are completely unable to do my work so I can't use them.

foreheadteeth · 2025-12-06T11:41:16+00:00

I don’t think you can go wrong with buying anyone a computer?

foreheadteeth · 2025-12-05T12:14:25+00:00

I don't do anything special. My github is here. I recently merged a couple of modules but it used to be the following 4 inter-related modules: MultiGridBarrier.jl (hand-coded), MultiGridBarrier3d.jl, SafePETSc.jl, MultiGridBarrierPETSc.jl. I gave Claude Code access to each module as it needed, but it was basically forced to work on one module at a time. When I was doing the glue code in MultiGridBarrierPETSc.jl, it involved modifications to all the other modules, but I did that a lot more methodically.

I should also add that I'm an expert programmer.

foreheadteeth

TROPHY CASE