512-byte OS Contest

[Troy Martin]

FAT writing as in writing files to the FAT and root dir on the floppy.

[VolTeK]

ah, well i will see what i can do, tommarow

[512dev]

What an entirely pointless topic..

I'm sort of surprised you're not more interested in this contest, but then again, maybe I shouldn't be.

Anyway, I attempted something like this years ago, and didn't get terribly far in it, but I wish everyone else good luck, I think we'll end up with some good projects this time around!

-512

[Troy Martin]

Interesting co-inky-dink that your name is 512dev and you're replying to a topic about 512-byte OSes..

[512dev]

Not exactly a coincidence, but I don't really feel like explaining right now, and it's largely irrelevant anyway considering that was a few years ago.

-512

[Love4Boobies]

Cool, 13 posts in almost 4 years...

[512dev]

Eh so I haven't been as active posting here as I should be =/

-512

[Troy Martin]

Just got an entry PM'd to me by Jacobbus, looks like some kind of pmode monitor!

[Jacobbus]

It's meant to be something like a hex editor
it allows you to edit the 4 GB addressable memory
it has one feature: by pressing enter the program at the selected location is executed that's what makes it an OS I gues
the bad news is that the program has to be coded by hand using the hex-editor
more info in the Readme.txt in the .zip

[Troy Martin]

Well, looks real nifty, good luck!

[Alboin]

Are the entries only going to be tested on QEMU or Bochs? (I've currently no test machine to use, atm; should I make something up.)

[Troy Martin]

Well, I test on Virtual PC for 16/32-bit stuff and Bochs 2.3.7 for long mode (*cough*E*cough) but I guess most will use Bochs and QEMU.

[Alboin]

Okay, so that means they don't necessarily *have* to work on a real machine, then, yes?

[Troy Martin]

Well, if they do work on RHW, I'd guess you could possibly get more votes from the public poll!

[inflater]

Mine entry: Inflater's Tiny-D0S - DOS EXE launcher in 512 bytes

Code: Select all

;;; Instrunctions!!!
;;; 1. Prepare a blank FAT12 floppy disk, insert it in drive A:
;;; 2. Copy any EXEs you like to it (please note that DOS INT 21h is
not supported and the EXEs need to access ROM-BIOS ints to work, one
such executable is in the archive)
;;; 3. Run WRITE.BAT - the EXEs will be kept intact there
;;; 4. Reboot the computer with the floppy in drive

;;; The only DOS function emulated here is AH=0x4C - exit function, which
;;; is configured to jmp far [0:0x7c00], that will reload this "OS" from RAM.
;;; Give me another 512 bytes to emulate at least five INT 21h functions :-P

Link in attachment.

Regards
inflater
@Troy: The e-mail I've sent you was for a reason...