iiinova — where your digital self keeps evolving

Tim Wiederhake @twiederh.bsky.social · 10/10/2026

Twenty lines of C, a dozen syscalls, and you have code running in a hardware-isolated VM on Linux. Sandbox plugins, run untrusted code, or spend five years writing a worse QEMU from scratch: twied.github.io/2026/10/09/a... - It does boot and run DOS though. #OpenSource #Virtualization #VM #Linux

FreeDOS booting and running in the KVM-based Virtual Machine "terrarium" that I wrote from scratch

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Tim Wiederhake @twiederh.bsky.social · 08/09/2026

My monitors broke rendering of some Qt apps on Linux: Buttons clipped, scrollbars half-invisible, text cut off. Turns out they report about 94 DPI instead of 96, and Qt's "PassThrough" scaling does not clamp to 1.0. Blog post with the fix: twied.github.io/2026/09/08/d-p-why/ #Linux #Qt

Screenshot of "QElectroTech", showcasing graphical glitches such as buttons being clipped, scrollbars being half-invisible, text cut off, and black smears in the drawing area where the region wasn't properly cleared.

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Tim Wiederhake @twiederh.bsky.social · 18/08/2026

Thanks for the feedback! I will check what the mixup is. Maybe it was dosbox-x, not dosbox, that was cycle accurate? Goes to show that no amount of proofreading saves you from this kind of mistake.

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Tim Wiederhake @twiederh.bsky.social · 18/08/2026

My x86 emulator now runs ROGUE (1984). New blog post about what it takes to go from raw bytes to a playable DOS game: loading MZ executables, memory management, and interrupt handling. twied.github.io/2026/08/18/m... #x86 #retrocomputing #emulation #dos

Screenshot of my x86rme emulator running ROGUE. Greeting reads "Hello twied, Welcome to the Dungeons of Doom"

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Tim Wiederhake @twiederh.bsky.social · 12/08/2026

I find "spite" an incredibly strong motivator. Go for it. And when you have done it, chest-thumping is recommended. The mad cackle is optional though.

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Tim Wiederhake @twiederh.bsky.social · 11/08/2026

I wrote an x86 emulator, from scratch, no dependencies. Full write up of what I learned at twied.github.io/2026/08/11/x... : ModRM is a tax form, instruction F6h takes 1.14 bytes of arguments on average, and you can double lock your instructions. #x86 #emulator #cplusplus #x86rme

twied.github.io

Getting intimate with x86

When you write a compiler, your work is usually done somewhere around the generation of machine-dependent assembly. But if you are like me, leaving cans of worms unopened is hard. And so I wrote an x8...

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Tim Wiederhake @twiederh.bsky.social · 05/08/2026

Created support for custom commands in #gitk: Define a name and shell command template and it shows up in the context menu. Placeholder substitution for commit id, author, file path, blame origin etc. Pull request: github.com/git/git/pull... #git #opensource

The new Commands tab in gitk's preferences window

Custom commands in the commit list context menu

Custom commands in the diff view context menu

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Tim Wiederhake @twiederh.bsky.social · 21/07/2026

Update: It landed. Sometimes one patch, two lines of documentation, needs three rounds of review. It's not glamorous, but still incremental improvement. #linux #kernel #opensource

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Tim Wiederhake @twiederh.bsky.social · 15/07/2026

Show of hands: who has a std::map somewhere in their code where the key is also a field inside the value? I certainly have. Turns out C++14 std::set with std::less<> enables heterogeneous lookup. No need to construct a full object. Just requires comparison operators. #cpp #cplusplus #programming

how not to do it: std::map with duplicated key

better solution: std::set with heterogeneous lookup

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Tim Wiederhake @twiederh.bsky.social · 05/07/2026

IMHO the best resources to learn OpenGL: ogldev.org and www.opengl-tutorial.org

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Tim Wiederhake @twiederh.bsky.social · 05/07/2026

TIL about `git absorb`. It automatically sorts your fixups into the right commits on a feature branch. Effectively `git commit --fixup` + `git rebase --autosquash` without the manual "what goes where" work, I love it. Curious what else I've been missing. #git #devtools

man.archlinux.org

git-absorb(1) — Arch manual pages

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Tim Wiederhake @twiederh.bsky.social · 30/06/2026

And Sourceware still makes you email their admin to ask for an account. I wish we had an SSO option that is not (indirectly) owned by some government or big advertisement networks.

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Tim Wiederhake @twiederh.bsky.social · 30/06/2026

I knew that the #Linux #Kernel review process was no joke. Still underestimated it. Round three for my two-line patch to improve some documentation of the MSR driver. #OpenSource

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Tim Wiederhake @twiederh.bsky.social · 28/06/2026

🤯 Goes to show that skill trumps tools

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Tim Wiederhake @twiederh.bsky.social · 08/03/2026

it bears saying again: a computer can never be held accountable / therefore a computer must never make a management decision.

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Tim Wiederhake @twiederh.bsky.social · 20/02/2026

Dipping my toes into #FPGA development and got a Sipeed Tang Primer 20k. Programming with #OpenSource tools is possible, but there are some gotchas. I have collected some more beginner-friendly examples here: github.com/twied/TangPr...

github.com

GitHub - twied/TangPrimer-20K-example: Examples for the Sipeed Tang Primer 20K FPGA using Open Source tools under Linux

Examples for the Sipeed Tang Primer 20K FPGA using Open Source tools under Linux - twied/TangPrimer-20K-example

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Tim Wiederhake @twiederh.bsky.social · 04/11/2025

Trying to figure out #meshtastic. Can receive just fine, but not send. Error message is "Max Retransmission Reached".

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Tim Wiederhake @twiederh.bsky.social · 29/10/2025

If your installation instructions are "curl | sudo bash", I will not use your software.

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Tim Wiederhake @twiederh.bsky.social · 20/10/2025

I hate Gimp. There, I said it. If I need to consult a tutorial to draw a circle, that's not a useful drawing program in my book.

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Tim Wiederhake @twiederh.bsky.social · 14/10/2025

I hope that it goes without saying that my intent of course was humor, not disrespect. Maybe add a "by" in front of the name? It is kind of redundant but prevents me from reading this as "The Real Problem of C++: Klaus Iglberger"

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Tim Wiederhake @twiederh.bsky.social · 14/10/2025

Unless Klaus is the real problem with C++, you might want to overthink that slide's design 😉

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Tim Wiederhake @twiederh.bsky.social · 05/10/2025

Once upon a time I opened a ticket in the #debian bug tracker. Eleven years later, there was a response: It was tagged "moreinfo" 🙄

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Tim Wiederhake @twiederh.bsky.social · 19/09/2025

Note to self: When using #podman, remember to install fuse-overlayfs, `podman info --debug | grep graphDriverName` should say "overlay", not "vfs". Container startup time went from 2:10 minutes to 0.7 seconds.

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