Hello, Assembly! Retrocoding the World's Smallest Windows App in x86 ASM

Dave builds the World's Smallest Windows application live in x86 assembly using only a text editor and the command line to assemble the program using the Microsoft MASM assembler.

Whether you're a professional programmer or just curious about how assembly language works, what makes it different from machine language, and why it can be faster and smaller than C you won't want to miss it! Take your Windows Programming to the next level. Or the previous level, depending on how you look at it!

Link to Mug:

Link to Code:

Thanks in part to a suggestion by 'SonicMouse' that I merge linker sections, the current binary size is 1488 bytes... and yes, it runs exactly the same.

0:00 Start
1:31 Assembly Language vs Machine Language
2:24 Machine Language Monitors
3:22 Hello, Windows!
5:10 Dave's Garage Mug
5:30 Task Manager Enamel Pins
6:04 Editor Sequence Start
10:15 Includes, Libs, Constants, Data
12:00 Main Entry
13:30 ShowWindow
15:11 WinMain
17:10 WindowClass
21:37 WndProc
26:15 Command Line
28:08 Running the App
28:30 Closing Thoughts

Environment: Windows 10 2H02, MacOS 11.2.2
GNU Nano Editor
Microsoft MASM SDK

PS: For anyone keeping score, two things are certain: (a) it can always be smaller, and I'm down to 1488 bytes now, and (b) Steve Gibson has likely forgotten as much about x86 assembly programming as I know :-). Thanks for the recent shoutout on the podcast!

I realize you can make a much smaller app by simply calling MessageBox, but that's why I outlined what I deem to be the "minimum functionality". SonicMouse has come the closest so far at 1776!

[CFSworks]

Fun fact: Roller Coaster Tycoon was written in assembly. There was just a little bit of C code to glue the game into the Win32 API. To date, it's the only assembly program that I know which *deliberately* contains crashing. :)

[paulveitch]

It's only low enough level if you've hand stitched it into rope memory as they did on the apollo flight computer. All these fancy text editors, pah!

[lxhon]

When I wrote some assembly code in the early 90s I wouldn't have imagined that one day I'd be seeing someone's screen with 753, 488, 695, 296 bytes of free space next to a 7, 292 bytes assembly code. Also: insane assembly coding skills displayed in the 21st century.

[tristynspies]

Been programming for 3 years, it's amazing how Dave shows you what true mastery looks like while remaining incredible humble. Makes you think about what it really means to BE a programmer. You sir are an inspiring.

[aarondewindt]

"As you know I wrote the Windows task manager." - That quote made me click the Subscribe button, you're one of my personal heros I never knew I had.

[RodCleaves]

Started a computer science course in 1966. At BU it was simply called programming, we used Dartmouth Timeshare BASIC. In my career the most sophisticated language I ever used was Pascal, GUI programming scared me. Recently, after retirement, I bought a few Raspberry PIs and learned Python. When I was at Digital Equipment Corp I taught their machine code and assembly language. All this has no value unless I want to start a YouTube channel. I love your videos Dave, they bring back a lot of memories.

BTW, my daughter was diagnosed with Autism but after years a tests it turned out to be CVI and I'm glad to say she's one of the few that has almost completely adapted out of the worst of it.

[TimLesher]

Watching Dave livecode is as relaxing as watching Bob Ross paint.

I haven't done Win32 programming in over a decade, but this brought back some great memories.

[maxinatorify]

7:06 Dave just casually flexing his typing speed :D

[Upgradeo]

From buying MS-DOS in a Retail Box, to watching the creation of the World’s Smallest Windows App, what a time to be alive!

[le]

It is actually scary to see this video and think "oh, looks like he is just speeding it up a bit." But then you look at the webcam and realize he is really typing this fast.

This man would dominate typeracer

[martysh]

Even for a modern C++ programmer, this gives a lot of insight to how programming was in the early 90s/late 80s. The commenting work is also very good! Learned some stuff I never knew about Windows.

[billstrader]

I also grew up in the '80s but I was in Louisiana. As you might expect, things were not great for a computer nerd during those days. I had my Commodore 64, banging out BASIC scripts, but I lacked resources or a mentor that could take me to the next level. My guidance counselors, who didn't understand computers, didn't encourage me to go down that path for a career. I literally thought you could be a scientist or work in a store. Retail is what I ended up doing for 10 years, though I was always building my own PCs. I finally broke into the IT support business and never looked back. Still can't code very well though. I wish I had focused on it more when I was young. So if you are a young person, or a parent of one, and your child shows an inclination to learn programming, by all means support them and try to encourage them to learn as much as they can.

[pezia]

This makes people appreciate 4k demoscene intros even more.

[emmanueloverrated]

You're a machine Dave. I've coding for 15 years and I can't still code that fast... impressive.

[SkarTisu]

Fascinating content, and Dave’s typing sounds like white noise since it’s so fast. That’s decades of time spent at a keyboard on display. Thanks for creating this!

[schulmastery]

I emailed Dave the other day about the Windows Message Pump, and he replied within 2 hours. This channel is awesome!

[wasekasi]

Wow, I really enjoy this channel and learning so much from you Dave. This was the best Assembly 101 short course I ever been in.

[stargazersfield]

Just found this channel. I have to say this now in my top 5 favorite channels to view. I see a flight full of downloaded Dave's videos. Well done sir. Glad to see we old nerds are still makin' it happen. This is also a great stroll down memory lane to coding in the 80's. Cheers

[StringerNews]

Health nut: "I ran a 4K yesterday."
Dave: "Oh, what did it do?
Health nut: wha?

[xXFastDathXx]

There's nothing more satisfying than building something from scratch and seeing it work! Thanks Dave!