Sijmen 🧑💻 @sjmulder@bsd.network
Programming, retrocomputing
Joined Aug 2018
Pinned post
Presenting SUDO for DOS!
An implementation of sudo for DOS, to run the given command with full privileges. It can be used to edit important system files, run disk partitioning tools, and so on!
Sijmen 🧑💻
boosted
A new article, this one about the application of Clausewitz's concept of friction to Software Engineering:
https://deadsimpletech.com/blog/friction_software_engineering
Sijmen 🧑💻
boosted
There was an article about moving to Codeberg on the orange website yesterday, and out of interest to get an impression of what average programmers think of the idea of moving, I took at look at the comments. (Yeah, I know …)
I’m going to write here my thoughts on a general impression of the comment thread as a whole. (Rather than respond to individuals.)
Sijmen 🧑💻
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New post: shell tricks that aren't exactly secret, but aren't always taught either.
Split into two sections: what works on any POSIX sh (FreeBSD, OpenBSD, Alpine...) and what's Bash/Zsh-specific. Because not everyone is on Linux with bash as their login shell.
Things like CTRL+W, $_, pushd/popd, fc, set -euo pipefail caveats, and more.
https://blog.hofstede.it/shell-tricks-that-actually-make-life-easier-and-save-your-sanity/
So a more practical question then - 27" or 32" for a 4K monitor?
27" at 150% = ~109 logical DPI
32" at 125% = ~109 logical DPI
32" at 150% = ~96 logical DPI
So the 27" would be squinting for old software, comfortable for newer defaults. 32" could do either depending on scale factor, but it's biiggg
Why have fonts, padding and other UI elements exploded in size over the past decade or so? Compare fonts in an IDE now with one from 10 years ago.
Is it Apple's push to 109 ppi (post scaling) on desktops and even higher on laptops? Things smaller on those screens -> designers making things bigger?
Sijmen 🧑💻
boosted
This is the work of a seasoned emulator developer, but still an impressive feat.
A 486-class PC emulator....
...in Visual Basic 6. And yes, you can run Visual Basic in it.
I'd like a keyboard computer like the Pi 400 that can hook up to monitors with just the single USB-C cable (USB-C PD/alt display mode)
Sijmen 🧑💻
boosted
Sharing because it's interesting:
CSMWrap is an EFI application designed to be a drop-in solution to enable legacy BIOS booting on modern UEFI-only (class 3) systems.
> "It achieves this by wrapping a Compatibility Support Module (CSM) build of the SeaBIOS project as an out-of-firmware EFI application, effectively creating a compatibility layer for traditional PC BIOS."
Sijmen 🧑💻
boosted
Could Go be a better C? I think so!
Meet Solod — a strict subset of Go that translates to C, without hidden memory allocations and with source-level interop.
Weekend bliss!
Going to work on a linker and, who knows, an age verification driver for FreeDOS
Found a fun way to confuse #pkgsrc: set it up on a 64-bit Pi with a 32-bit OS. The kernel will be 64-bit still, causing search path confusion in check_shlibs.
The workaround, pending a better solution: bootstrap --machine-arch arm
I am seriously tempted to buy #ArcaOS even though I have absolutely no use for it other than tinkering
Presenting SUDO for DOS!
An implementation of sudo for DOS, to run the given command with full privileges. It can be used to edit important system files, run disk partitioning tools, and so on!
Sijmen 🧑💻
boosted
OK, apparently couldn't resist one more feature in #QRPaint (v0.9.4).
Added a Spray tool with a slightly over-engineered random spray and flow rate. 😄
https://bbbbbr.itch.io/game-boy-qr-paint
Sijmen 🧑💻
boosted
🚨 Spring is upon us! 🚨
To celebrate this we want to announce, with a little more time this time, the next edition of the BSD-NL Conference.
BSD-NL Conference - Spring 2026 🐡😈⛳
📆 2026-05-09 / May 9th 2026
🕐 10:00-23:00 CET
📍 Brouwerij Maximus (Utrecht)
🌐 https://bsdnl.nl
If you have a talk prepared already we want to hear from you! You can submit your abstract at https://events.bsdnl.nl/
Hack! You can even register for the event already... the price we charge is to cover lunch. https://tickets.bsdnl.nl/bsdnl/early-26/
#BSDNL #RUNBSD #BSD #OpenBSD #FreeBSD #NetBSD #HardenedBSD #SecBSD #DragonflyBSD
I am also quite impressed by Windows NT, as I learn more about its workings. For example, its desktop and session architecture is something Linux desktops could learn from.
...and then I remember what became of it 
Programming some small DOS programs has made me learn a bit more about it, and real-mode programming in general.
For example, I thought DOS was essentially a single-process, full memory ownership sort of affair (sans resident code hacks), but that's not true at all. Multiple programs can be loaded at the same time, with DOS keeping tabs of memory allocations. The basic variant of this being one program starting another, and then the second exiting, returning to the first.
(But let's not make $-terminated strings a thing again! Or length-prefixed, \r-terminated strings, wat)
Sijmen 🧑💻
boosted
A very detailed tutorial from "Joaquin Pinillos"
Walk x86-64 page tables by hand in qemu and gdb. Decompose a virtual address, follow cr3 through all levels of physical memory, and extract a flag from raw bytes.
I've found a reasonable stopgap solution, which is to run DOSBox-X in Termux with Termux:X11, which also makes file sharing with DOS trivial!
Now to finish my very useful program...
Programming, retrocomputing
Joined Aug 2018
