Chris Williams @diodesign.org · 11/09/2026Working on a native BIOS/UEFI-like GUI for the Diosix.org RISC-V hypervisor. Beyond an in-guest CLI and Linux kernel driver, I’m experimenting with a graphical console to configure guest VMs, storage, networking, and more directly on screen-attached RV64 hosts. WIP! github.com/diodesign/di... 151
Chris Williams @diodesign.org · 02/07/2026Working on adding a Unicorn-based emulation layer to my 64-bit RISC-V hypervisor so you can run non-native guests (riscv32, aarch64, x86_64) seamlessly. Below, the green text is console output from an x86 Linux guest amid hypervisor debug traces. Still WIP! More: github.com/diodesign/di... 000
Chris Williams @diodesign.org · 18/06/2026Looking forward to developing on this 64-bit RISC-V Spacemit K3 Pico-ITX system: * 8 2.4 GHz RVA23 CPU cores with hypervisor and vector extension * 8 AI accelerator cores * Whole load of IO: USB, 1G Ethernet, 10GbE SFP+, Wi-Fi 6, and more www.spacemit.com/community/do... 150
Chris Williams @diodesign.org · 15/06/2026I like this warts-and-all reverse-engineering documentary by David Given of this 6502-based system. From extracting the firmware to figuring out the device architecture, it's a realistic journey for anyone interested in this kind of forensic work www.youtube.com/watch?v=jJ0X...youtube.comReverse engineering a 'tony' 6502-based game consoleYouTube video by Poking Technology 184
Chris Williams @diodesign.org · 10/06/2026Gerph is working away on a 64-bit version of RISC OS, the original Arm operating system first developed by Acorn in the UK. I think it's a super interesting project. He did a Q&A about this effort here: www.youtube.com/live/Oy_mCJf... His summary here: www.riscosopen.org/forum/forums...youtube.comGerph's live coding - Quick Q & AYouTube video by Gerph 162
Chris Williams @diodesign.org · 10/06/2026Super fun logo generator, inspired by the ZX Spectrum's Sinclair branding, by Dave Thomas. Online: dpt.github.io/SinclairLogo/ Info: www.davespace.co.uk/blog/2026060... Code: github.com/dpt/Sinclair... Web plus creative coding times retro computing equals... this 140
Chris Williams @diodesign.org · 05/06/2026The code and hardware design behind Sum Ergo Demonstro, lft's impressive real-time demoscene creation powered by a dual-core IO-stuffed and overclocked RP2350 RISC-V microcontroller: www.youtube.com/watch?v=0_9Y...youtube.comMicrocontroller Magic: Under the Hood of “Sum Ergo Demonstro”YouTube video by lftkryo 120
Chris Williams @diodesign.org · 30/05/2026I rewrote my RISC-V hypervisor in Zig and added support for new features like hardware virtualization (H extension). It previously used segmented physical memory for guest isolation, and will fall back to that if H is not present. asciinema.org/a/XbV4OoBD8G... Need to tidy up the codeasciinema.orgFirst RISC-V Linux guest boot of Zig Diosix hypervisorDiosix, rewritten in Zig for 64-bit RISC-V systems, boots a guest virtual machine, and allows console-based interaction with this VM. 030
Chris Williams @diodesign.org · 30/04/2026For further proof that OS development is hard: copy.fail A page cache corruption that stays in memory but never hits the disk. Since the disk remains "clean," checksums don’t catch it. It allows unprivileged users to gain root or escape containers by corrupting shared memory of sensitive binaries.copy.failCopy Fail — 732 Bytes to RootCVE-2026-31431. 100% Reliable Linux LPE — no race, no per-distro offsets, page-cache write that bypasses on-disk file-integrity tools and crosses containers. Found by Xint Code. 111
Chris Williams @diodesign.org · 30/04/2026Huge props to reassembler who is porting Sonic from the Megadrive/Genesis to the Amiga. Despite both sharing a Motorola 68000-powered base, Sega's tile-based architecture is pretty different to the Amiga's bitplane approach, so my hat's off for getting this far... www.youtube.com/watch?v=nWqK...youtube.comSONIC: playable on real Amiga hardware for the first time (somewhat)YouTube video by reassembler 000
Chris Williams @diodesign.org · 18/04/2026Developing a Dungeons & Dragons style NES RPG in 6502 assembly must have been tough, even if its programmer thought the job was "pretty simple" due to his experience with the Apple II.* Still, the code was fairly buggy, as illustrated in this cool video below * www.gamesradar.com/games/final-... 010
Chris Williams @diodesign.org · 08/03/2026It's in the Internet Archive, for those who are curious. archive.org/details/mach... 062
Chris Williams @diodesign.org · 09/02/2026Super-in-depth look at the 6502 assembly in a NES game, with lessons for today's code in terms of performance optimization decisions and missteps 030
Chris Williams @diodesign.org · 09/02/2026A cool demonstration of Zig as a language IMO: a PlayStation 1 emulator with built-in dissembler and debug. It emulates the 32-bit MIPS 3000A-based CPU core as well as the Sony GPU, GTE, SPU, and more Readable code, too, and links to system reference info github.com/maxpoletaev/...github.comGitHub - maxpoletaev/nupsx: Experimental PlayStation 1 emulatorExperimental PlayStation 1 emulator. Contribute to maxpoletaev/nupsx development by creating an account on GitHub. 022
Reposted by Chris WilliamsChrome for Developers @developer.chrome.com · 08/01/2026New year, new account, same great open source energy. We are ready to see what you ship 🚢 1254
Reposted by Chris WilliamsGoogle Open Source @opensource.google · 06/01/2026New year's resolution, engage with open source developers on our new Bluesky account. ✨ 2828829
Chris Williams @diodesign.org · 02/01/2026This is going to date me, but in college I studied 90 to 45nm processes for my EE degree. I asked a professor about sub-45 and his response was: "oh, that's just dark magic." I dunno how he'd describe sub-10nm. Anyway, if you don't know how modern chips are made, check this out 020
Chris Williams @diodesign.org · 31/12/2025RIP Stewart Cheifet. who died December 28. He was 87. I have no doubt his work creating and hosting the Computer Chronicles from 1984 to 2002 inspired many future journalists and engineers. Certainly was for me. obits.goldsteinsfuneral.com/stewart-chei... en.wikipedia.org/wiki/Compute... 130
Reposted by Chris WilliamsLiam Proven @lproven.bsky.social · 23/12/2025UNIX V4 tape successfully recovered: First ever version of UNIX written in C is running again www.theregister.com/2025/12/23/u... Crucial early evolutionary step found, imaged, and ... amazingly ... works <- by me on @theregister.comtheregister.comUNIX V4 tape successfully recovered: Crucial early evolutionary step found, imaged, and ... amazingly ... works 3237
Chris Williams @diodesign.org · 12/11/2025This was pretty interesting, hearing how the small team behind the 8-bit BBC Acorn computer went from specifying ULA chip designs to designing the early Arm CPU series from scratch using BBC BASIC www.youtube.com/watch?v=W2yD...youtube.comFrom Acorn to ARM with Professor Steve Furber MBEYouTube video by The Retro Collective 042
Chris Williams @diodesign.org · 22/09/2025And on to another week. Grateful for everything, especially these views from the weekend. 040
Chris Williams @diodesign.org · 22/09/2025If you want to get started writing your own kernel for 32-bit RISC-V from scratch, here's how seiya.me did it in 1,000 lines of cleanly written C. There's documentation to go with it. Pretty cool IMHO! github.com/nuta/operati... 130
Chris Williams @diodesign.org · 25/08/2025A 1956 general-purpose digital computer, the Bendix G-15, plus an algorithm from the modern-day CERN ATLAS experiment equals... this: www.youtube.com/watch?v=2y0D... What takes under a microsecond on hardware today takes about 15 minutes on this vacuum-tube machineyoutube.comCERN Topoclustering on the Bendix G-15!YouTube video by Usagi Electric 021
Chris Williams @diodesign.org · 17/08/2025Wonderfully detailed per-frame performance analysis of NES Metroid, and why it lags at certain points. It's super interesting to see the software engineering decisions taken back in the day. As always, a great video by @displacedgamers.bsky.social IMO www.youtube.com/watch?v=3G6v... 030
Reposted by Chris WilliamsSteve Klabnik @steveklabnik.com · 10/08/2025#ziglang ’s Lovely Syntax matklad.github.io/2025/08/09/z...matklad.github.ioZig's Lovely SyntaxIt's a bit of a silly post, because syntax is the least interesting detail about the language, but, still, I can't stop thinking how Zig gets this detail just right for the class of curly-braced langu... 97812
Chris Williams @diodesign.org · 19/07/2025I like alternative languages and architectures to see how syntax, structure, and other implementation details can be done differently. There's not only ziglang.org which I think is cool, but also SystemVerilog alternative Veryl: github.com/veryl-lang/v... Yet another side project coming on.github.comGitHub - veryl-lang/veryl: Veryl: A Modern Hardware Description LanguageVeryl: A Modern Hardware Description Language. Contribute to veryl-lang/veryl development by creating an account on GitHub. 110
Chris Williams @diodesign.org · 16/06/2025This looks like a super meeting for those interested in Acorn, Arm, and RISC OS history 094
Chris Williams @diodesign.org · 07/06/2025FYI: Gerph has been re-implementing RISC OS – which started as Arm's very first OS – in Python, allowing 32 and 64-bit apps and other software to build and run on non-Arm systems. Amazing work More on RISC OS Pyromaniac: pyromaniac.riscos.online Latest here: www.riscosopen.org/forum/forums... 195
Chris Williams @diodesign.org · 29/05/2025Recently enjoyed seeing and listening to quite a mix of live music in the Bay Area, from Kylie and Underworld in San Francisco to Kraftwerk in Berkeley. All pretty stunning, and all great sounds I grew up with that I finally got to experience in person. 030
Chris Williams @diodesign.org · 30/12/2024Watching some old EEng videos, because why not, and find a 50-min 1988 video from Intel about the design and challenges of its 386 CPU And look who shows up, in his late 20s, talking about mixing automation and hand drawing of transistor layout on silicon and more www.youtube.com/watch?v=LQcL... 180
Chris Williams @diodesign.org · 24/12/2024More adventures in #Zig and bare-metal RISC-V! Heap allocator is done, with merging of adjacent free blocks. A little more atomics for multi-CPU/thread support. And lots learned about the language. github.com/diodesign/di... And now onto device tree parsing and generation... 130
Chris Williams @diodesign.org · 18/12/2024It's the holiday season, I've got some time off work, and so I'm gonna finally dive into Zig and RISC-V ziglang.org riscv.org/developers/ I've got bare-metal execution in Qemu, writing hello world out to the serial port. Let's bring up more of an environment and then try this on real hardware... 250
Chris Williams @diodesign.org · 13/12/2024RISC-V CEO Calista Redmond resigns -- I have high hopes for RV, as I'm all for market competition. Calista had a tough job driving through a new ISA and IMHO did great riscv.org/riscv-news/2...riscv.orgRISC-V CEO Calista Redmond resigns after 5+ years of progress – RISC-V International 120
Chris Williams @diodesign.org · 18/11/2024Been a fan of Orbital since I was a teenager. Never got the chance to see them live in the UK. Super happy to have caught them on tour in San Francisco this weekend. Amazing night of progressive-house-techno-whatever you want to call their unique sound :) 040
Reposted by Chris WilliamsKelsey Hightower @kelseyhightower.com · 15/11/2024The tech migration from Twitter continues. One by one. 1544928
Reposted by Chris WilliamsThe Register @theregister.com · 13/11/2024OK, now that the stampede to BlueSky has died down for a moment, and systems are a bit more stable, let's try sharing this again - our starter pack. Thanks for joining us! go.bsky.app/EsDR7M7 0329
Chris Williams @diodesign.org · 18/08/2023Debian has been a bedrock for me. Pretty much every dependable system I use has Debian at its core. I can't imagine using any other OS www.theregister.com/2023/08/17/debi…theregister.comDebian turns 30 – and important to Linux world as everAugust 16 was an especially big day for this island of stability 061
Chris Williams @diodesign.org · 12/08/2023I quite like the design of this, and that it's aimed at devs. Neat way to get secure P2P into apps. Written mostly in Rust, too 010
Reposted by Chris WilliamsThe Register @theregister.com · 09/08/2023First Zenbleed, now Downfall. We've got a fab overview of these two data-leaking CPU bugs in AMD and Intel processors, both found by Googlers, here: www.theregister.com/2023/08/09/goog…theregister.comDownfall data-leak vulnerability found in Intel processorsIt is with a heavy heart that we must announce that the boffins are at it again 011