Per Vognsen

https://mastodon.social/@pervognsen

I like programming and understanding how stuff works. My background is in systems programming and game development.

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npub19kyqnmj2a8k6ul224zrel2cc6xtl5xtkyf7nz304mexxp393xyasy396vu

NIP-05 Address

pervognsen_at_mastodon.social@momostr.pink

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nprofile1qqszmzqfae9wnmdw04923pul4vvdr9l6r9mzylf3gh6aunrqcjcnzwcprpmhxue69uhhyetvv9ujumt0d4hhxarj9ecxjmntea2ghn

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relay.momostr.pink

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npub19kyqnmj2a8k6ul224zrel2cc6xtl5xtkyf7nz304mexxp393xyasy396vu

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Last Notes

2026-07-06 15:54:24 UTC

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It's hard to find reliable, up to date numbers on Minecraft MAU but it looks like it's in the 100-200 million range. Not sure where they plan to find the remaining 800-900 million given that Xbox Series S and X lifetime hardware sales is apparently ~30 million.

2026-01-21 01:59:56 UTC

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I guess these aren't conventional hazmat suits but styled after the suits you'd wear in a semiconductor fab? So it's not totally arbitrary.
Confirmed on the Wikipedia page for cleanroom suits: "More advanced designs with face covers were introduced in the 1990s (like the Intel fab worker-style suits seen on the Pentium product advertisements)."

2026-01-21 01:57:50 UTC

https://files.mastodon.social/media_attachments/files/115/930/606/352/765/906/original/18f18ae8708aa656.png

2026-01-17 23:14:26 UTC

ASCII characters are not pixels: a deep dive into ASCII rendering. https://alexharri.com/blog/ascii-rendering

2025-08-08 12:03:27 UTC

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This is good too.
https://files.mastodon.social/media_attachments/files/114/993/044/195/238/530/original/a6c270f25e99aece.png

2025-08-08 11:59:32 UTC

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Stained glass is a wonderful way of visualizing the overlap.

2025-08-08 11:52:38 UTC

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It must be a little sad to be reduced to something like that. Even now Hoare is "the quicksort guy" to most people, if they know who is he at all. I admittedly don't know anything else about Venn!

2025-06-20 03:28:33 UTC

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The culture of extensive reverse engineering and binary patching to extend proprietary dev tools on Windows has always made me smile. This is one of the crazier examples: https://gitlab.com/VC6Ultimate/VC6Ultimate

2025-06-20 01:50:03 UTC

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<3 The Dead

2025-02-24 01:12:27 UTC

Anyone know what GUI set the precedent for triggering widget actions on mouse button release rather than press? As a follow up, what about the specific convention where you can press a button with the mouse cursor over a widget, move the cursor off the widget, release the button and the action does not trigger? Original Mac? Earlier?

2025-02-07 00:12:16 UTC

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Random neurons firing, pun very much intended: dunno if you're familiar with this year of the ICFP programming contest but it's one of my enduring memories and the text adventure problem (section 3.9 of this retrospective paper) was kind of a linear-logic proof search problem in disguise. http://boundvariable.org/press/tr-06-163.pdf

2024-12-01 20:57:43 UTC

Fast conditional breakpoints via eBPF!?! Let's go! https://pernos.co/blog/linux-kernel-additions/
"With the new feature we contributed to 6.10 it's instead possible to filter the breakpoint hits in the kernel without ever trapping to rr or using ptrace. We can install a hardware breakpoint via the perf events subsystem and attach a BPF program to it that checks for matching register values and suppresses signals for those iterations that are not of interest."

2024-11-29 00:56:43 UTC

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Ah, I wasn't referring to that. I'm familiar with CNOT; I was not commenting on specifically but reversible computing more generally after reading your link about reversible computing (where you give some stack examples). It was just a random observation on two-operand instructions for register (not stack) machines being more reversible by default than three-operand register instructions.

2024-11-28 20:44:58 UTC

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In that case you're effectively building a reversible machine extending the original non-reversible machine by augmenting the non-reversible cases of the instructions with reversible semantics by conditionally pushing/popping to the garbage stack. That way the extended semantics are reversible while retaining the original non-reversible semantics for the original subset of the machine state (the register file and memory).

2024-11-28 20:27:06 UTC

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That reminds me of something that occasionally comes in handy if you want to build a compact reversible trace buffer for a non-reversible register machine: two-operand CISC-style instructions are more reversible than three-operand RISC-style instructions. You can execute xor, add, sub, rol, ror backwards as long as rd != rs.

2024-11-25 21:35:00 UTC

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"You know who else liked to draw things?"

2024-11-11 14:19:31 UTC

Just Windows things: https://devblogs.microsoft.com/oldnewthing/20050715-14/?p=34923

2024-10-21 09:01:03 UTC

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AI Clippy is going to make a comeback, I'm sure.

2024-09-14 02:44:11 UTC

Apropos of nothing in particular, King Arthur's World was one of my favorite games to rent on SNES as a kid. Basically a very weird mix of puzzle, RTS and Lemmings. As far as I know there still isn't really anything else like it. https://www.youtube.com/watch?v=IFjQuKtFkTE