The Fourth 512-byte OS Contest!

[js]

Here's a compilation of all bootsectors into one floppy, plus a (grub) menu to choose between entries and display source code (page by page) and aditionnal information (incl. "real" size of the code (without the zero padding)).

@a427 : Maybe you could add it to your first post to allow easy testing ?

I tested everything in qemu, and it works exept :
* snake doesn't work (red screen) for some obscur reason (I'll check if the sector isn't corrupted...)
* game of life doesn't work in general when launched by grub. I think it's because it doesn't clears the screen (so you have the "conway game of life" part, but not the "star wars" part, which is hidden in junk).
* I couldn't hear sound for any of them, but this is likely to be a qemu configuration problem on this machine.

To use it :

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qemu -fda contest-entries.img -soundhw pcspk -net user -net nic,model=rtl8139

Downloads :
* floppy image, raw (1.5Mb)
* floppy image, gzipped (170k)
* floppy image, zipped (170k)
* Source code (650k)

[Gigasoft]

QEMU doesn't support MIDI sound AFAIK. Bs_antm has to be run in Bochs. To get proper results, SB16 emulation must be enabled by checking the Enable SB16 emulation box right before starting emulation (because it has problems saving and loading this setting), and Synchronization should be set to realtime in the Clock & CMOS options.

[Krap]

* snake doesn't work (red screen) for some obscur reason (I'll check if the sector isn't corrupted...)

I haven't tested your compilation, but in the "raw" version, this just means... you've lost your game
It doesn't restart after loosing.

* game of life doesn't work in general when launched by grub. I think it's because it doesn't clears the screen (so you have the "conway game of life" part, but not the "star wars" part, which is hidden in junk).

Yes, this is one on the reasons i didn't want to post it as-is, but no time to rework it. The same problem appears in vmware or virtualbox IIRC, and maybe with bochs too, but not on true hard boot. I was pretty sure switching video modes was supposed to clear the associated video memory, but it seems i was wrong Another strange thing is that on real hardware boot, its really very slow while in qemu, it's correct, and in virtualbox (or vmware, my memory is really down today), it's near you don't see the shapes because of too high speed (all on the same PC). It seems emulators did a great optimization job (sure, they don't restrict themself to 8086 instructions like i did )!

* I couldn't hear sound for any of them, but this is likely to be a qemu configuration problem on this machine.

This sounds strange ; mine works nicely here with

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qemu -soundhw pcspk TheImperialOuch

. Tip : did you mute your speakers ?
That's a bad news, since the compo lose a lot of its interest (not artistic, really, but technical) if the sound doesn't work (and more if screen isn't cleared)

[a427]

@js : Nice job !! I put a note in first post.

Your compilation of the 10 entries is very handy ! I particularly like to be able to browse all of them side-by-side,
with description plus source-code.
We can even test all sequentially in the same qemu session by issuing a 'system_reset' in qemu console !

Sadly, I confirm that this method breaks entries that expect a blank video memory.

Maybe a solution to this would be to use grub2, that I believe implements a 'write' command, that allows writing arbitrary memory address..
then, before booting an entry, simply fill the video memory with zero..
Well it's just an idea, and I'm not sure if this would be feasible in fact...

Anyway, thanks again for your work !

[a427]

Just a reminder that the poll is open, so please vote right now for your favourite entry !

The poll is open till 31 january !!

[Coty]

LOL, you can remove my wordsmith I never uploaded the fixed version

[a427]

@coddy
well I won't remove it from the poll though, else it would reset the current results..

too bad you didn't release improved versions..

[a427]

Well, it seems like this contest is over now...

Congrats to all participants, whatever the poll results (not really significative) !!
Some entries were really amazing ! Anyway, thanks for your time and your interest.. (I had a hard time organizing the fourth edition)
(I thought more people would have been interested in this contest and voted but, hah, so is the life...)


See you later for more competitions maybe..

a427.

[XanClic]

Seems to be hard for the one who "initiated" this contest to congratulate himself...

Thus I'll do that. Congratulations to you, a427!

[a427]

Seems to be hard for the one who "initiated" this contest to congratulate himself...

Thus I'll do that. Congratulations to you, a427!

Hehe, thanks...
I really liked your ethernet-capable OS too !

Good luck with your entry for the fifth contest !
I tried it and managed to boot my custom 32-bit OSLOADER with it...
I too have to bootstrap OSLOADER in realmode... (need to work a bit more on my entry for that)

[Krap]

Congrats mr a427

[a427]

Congrats mr a427

Hehe, you don't say

Your entry was not bad, too.. Eventually you could enhance it to use modern 386 instruction sets, shave some bytes,
and reset video RAM to zero....