MARS.EXE → COM (2021)
40 comments
·July 12, 2025skrebbel
112233
yay, another person with a bookmark to webarchive copy of that thread. dune's (Lassi Nikko) post about the making of the music for cdak was equally metal, if a bit too short.
reconnecting
I remember when I saw MARS.EXE for the first time on my 386. That was something absolutely unimaginable for real-time graphics. Pure magic!
It's fascinating to see that 30 years later someone is still working around its source code.
rwmj
I remember when the demo came out (I didn't even know it was called a "demo" at the time). We gathered around it running on one of the lab PCs. It was quite unbelievable that something like it could be done in such a tiny executable.
reconnecting
Yeah, I had exact the same fellings.
feiss
same feeling
dvh
Have you also tried to reach the end?
reconnecting
Of course, that was the first intention, to get to the end.
I remember as a child, I had spent a lot of time on this, but perhaps the direction was wrong. (-:
reconnecting
Description from pouet.net and how it works (1)
The Mars demo was written by Elixir's resident graphics guru and Head of R & D Tim Clarke in 1993, whilst he was still at school. Freely distributed on the Internet, the demo soon gained legendary status for its ability to generate fractal terrain and render it real time, all with a meagre 5K. As a result Tim was headhunted to work for space agency Lunacorp in Washington for several summers whilst studying at Cambridge University.
We recommend running this in DOS mode as it was designed to run on a 386 and may well crash Windows. Remember that this demo was designed for machines that were around in 1993! Use the mouse to move around and press any key to quit.
Agingcoder
I remember mouse control - I didn’t expect in a dos application at the time, and it also felt like a waste of space ( I think you had to fiddle with interrupt 33 or something like that to deal with the mouse which was more complicated than basic port reading )
nopakos
One of the first emails I've sent in my life was to Tim Clarke asking how Mars did work and I was so happy he answered! I remember the graph with the stars.
reconnecting
I didn't have any access to email at this time, and Mars looked to me like people somewhere out there were playing with real-time generated 3d virtual worlds while I was stuck with Windows 3.1 forever and no one would rescue me.
amiga386
It's a classic demo. The question is, how does the size-reduced version perform on an 80386? (as opposed to a multi-gigahertz machine trusting DOSBox to emulate a 386)
fl0id
at the end, it says it was at least tested to compile (and presumably run) on real machines.
baal80spam
Beautiful.
For comparison: In Windows 11, Notepad's size, referring to the disk space it occupies, is approximately 25.1 MB according to the Microsoft Store.
reconnecting
For comparison, the size of this HTML page + CSS is larger than MARS.EXE was.
dcrazy
That seems inevitable, given the webpage contains an assembly listing of MARS.EXE. Mnemonics are larger than machine code.
reconnecting
I meant the source of this page, including the transparent pixel image and the logo.
GuB-42
How did it get that big? On my Windows 10, notepad.exe is 196 kB, I remembered it being under 100 kB, but it did get a few more features in the last years. Anyways, hard to judge considering that a good part of the original Notepad is likely to be standard Win32 components.
Anyways, none of these "mainsteam" apps hold a candle to sizecoding productions. Just look like what comes out of Lovebyte, a demoparty where no production is above 1 kB.
pixl97
Win11 notepad has multiple tabs and previous session saving, which is nice. But it also has a bunch of other crap such as copilot integration and it's logged into your Microsoft account.
GuB-42
So Notepad quickly went from decades of not having the most basic features, like support for UNIX like endings and files larger than a few kBs, to a 25 MB monstrosity...
As if they tried to avoid the sweet spot the best they could.
accrual
Microsoft recently added both Copilot integration and rich text formatting (!) options to stock Win11 Notepad. Fortunately, they can be turned off for now.
I do like that the rich text support allows converting to/from Markdown, but I still prefer plaintext mode.
reconnecting
I thought copilot integration was sarcasm.
hypercube33
I think they moved it to .net, made it a store app, dark mode and copilot ai.
rkagerer
WTF? On Windows 7 it was 189 KB
phkahler
I remember seeing this, reading the high level description of how it works, and doing my own implementation in school. Probably in Turbo Pascal on a 486.
tetris11
Ive looked for an online dosbox that would let me load the ASM, but weirdly found nothing.
reconnecting
Have you tried this one?
tetris11
Oh wow, really nice -- took me a while to realise that hitting a key exits the program and that it only responds to mouse input
null
Andrew_nenakhov
MARS.EXE... Now, that's a name I've not heard in a long time. A long time.
HourOrTwo
[dead]
null
The explanation is a great read. It reminds me of Unc's amazing explanation of how they did "cdak", possibly one of the best 4k demos ever made:
https://web.archive.org/web/20150112121832/https://www.pouet...
(for completeness, cdak pouet/download page: https://www.pouet.net/prod.php?which=55758 - youtube capture: https://www.youtube.com/watch?v=RCh3Q08HMfs)