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Wrap Up / Conclusion
Noxide

My main goal for this project was to make an app that I'd actually use going forward and I kinda got close to accomplishing that. We'll see if I improve it to the point where it can do all the stuff I used to use calc.exe for.

Another goal was to have a starting point for the machine code editor I really wanted to make and I definitely accomplished that.

For anyone (and for myself later) wondering what it's like programming machine code in an ASCII hexdump, here's a video of me in the middle of it:

calx_clip.mp4

The main problems I've encountered programming in machine code:

  • manually doing rip-relative offset math
    • x64 being non-fixed length makes this extra annoying
    • but adding padding to align things makes it less annoying
  • manually encoding parameters in the REX, ModRM, and SIB bytes
  • remembering the bytes for an instruction
    • copying template instructions and twidd
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Update 2
Noxide

I was working on the machine code editor I mentioned in Update 1 all the way up until today (the last day of the jam) so I decided to just make the calculator in C for the following reasons:

  • There's no way I could finish the calculator app in time if I first gotta finish the editor
  • I don't think the editor is really on theme so I didn't want to submit that
  • I still wanted to finish SOMETHING and submit it

Here's a screenshot of the calculator app - it's a small window that shows up in the top right when I run it (and I have it on the PATH so I can win+r to run it quickly). I can specify numbers in hexadecimal or decimal and specify either + - / or * and the result is just always present (no need to press '=').

Screenshot 2026-04-19 164442.png

You navigate through the operands with hjkl and yo

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Update 1
Noxide

I originally intended to make a whole calculator app in an ASCII hexdump of the exe header + machine code. However, I got one function in and couldn't do it anymore. But after that experience, I now know more about what the exact problems with programming in machine code are. And with that knowledge I started building the editor for machine code that I've been wanting to do since my previous Handmade jam entry, AmpItUp. I now have a somewhat working editor for machine code. I'm going to fix it up a bit more, maybe do a post explaining what's going on in this screenshot, then try making a calculator app that I'd actually use instead of calc.exe. Here's a screenshot of the editor so far: Screenshot 2026-04-17 184900.png

Also I thought it was funny to paraphrase Thoreau for a response to the "why program in machine code?" question:

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