Recent Posts

1

Example Code / Re: Snake game for MS-DOS (16-bit real mode)

« Last post by Tobiasz Stamborski on May 27, 2025, 12:04:06 PM »

Yeah, I'll go to some random website and load up a program written in assembly in my browser.

I don't understand why exactly you are so malicious. If you are suggesting that i sell malware then simply no. The game is all running inside emulator (js-dos) inside web browser - i don't know how it even could do anything harmful to your computer. afaik it can only save few kB of data inside a cookie.

i don't feel itch.io is a random site. it's well known site for indie games and corelated stuff. i don't want to argue - if you are a moderator and you think my post is inappropriate here then you can delete it.

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Example Code / Re: Snake game for MS-DOS (16-bit real mode)

« Last post by debs3759 on May 26, 2025, 10:24:16 PM »

Yeah, I'll go to some random website and load up a program written in assembly in my browser.

3

Example Code / Snake game for MS-DOS (16-bit real mode)

« Last post by Tobiasz Stamborski on May 21, 2025, 02:15:47 PM »

Hello,

I want to share with code of my snake game implementation. I know it's rather a full program than an example code.
But i think maybe someone will use it as an example of simple random number generation, playing simple music on the
pc speaker, or anything else. Sorry if i shouldn't post it here.

If you want to see the game, here is a page on itch.io where you can play it in the web browser:
https://tstamborski.itch.io/wild-snake-boa-ii
However HTML5 player there works a bit slow and jaggy. (idk exactly why, in DOSBox it runs fine)

The full source code can be found here:
https://github.com/tstamborski/wild-snake-boa-ii
snakeboa.asm is the main file where program starts.

Sorry for my stupid ideas like making a wallpaper. (if somebody downloaded SNAKEBOA.zip and noticed)

I have created the game for game jam - just to try your hand. It's all running in text mode and just default BIOS
font is replaced by my custom 8x8 font. It's maybe nothing interesting but i thought why not to show it here.

4

Programming with NASM / Re: how to switch video modes (switching to VESA video modes too) in protected mode

« Last post by Tobiasz Stamborski on May 17, 2025, 02:26:01 PM »

Hi, I am Lukas,
and I am writing my operating system but I have problem with switching video modes ( switching to VESA modes too ) because I don't know how to do it and I don't found any tutorial on it so I need help. I know that in real mode it can by done by using ah = 0x00 and with interruption 0x10, but I am in protected mode so I don't know how to do it. Can someone help me please?

It don't know does it helpful for you, because it's just about regular VGA modes but:
1. In protected mode you haven't access to BIOS interrupts as you already know. You must to deal directly with VGA i/o registers by self.
2. Here you have the short instruction about VGA registers (how to use them):
https://wiki.osdev.org/VGA_Hardware#VGA_Registers
3. Here you have a proper register settings for few VGA modes (and how you should safely set them up):
https://wiki.osdev.org/VGA_Hardware#Sample_Register_Settings

Generally it's a lot of work before you, so don't expect a simple answer. I think links above are good place to start. BTW: Not so long ago I was trying to write my own simple OS too. I know your pain.

5

Website and Forum / Re: Why did the site go down just a few days ago?

« Last post by debs3759 on May 01, 2025, 03:54:09 AM »

That's just speculation, most of us have no idea whether it was a network issue or a software issue. Or something else. No point pointing fingers until someone in the know responds.

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Website and Forum / Re: Why did the site go down just a few days ago?

« Last post by ben321 on May 01, 2025, 02:57:17 AM »

Assuming the server admin is paying their ISP for a static IP address then you shouldn't have this kind of issue. This kind of issue happens issue when the IP address associated with the domain name becomes obsolete due to the IP address being dynamic (ISP periodically changes your IP address).

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Website and Forum / Re: Why did the site go down just a few days ago?

« Last post by debs3759 on April 30, 2025, 06:11:50 AM »

I think it was down for over a week. That's not unusual, as the server isn't regularly monitored, amd the site admin isn't around much. It is run by volunteers after all (even if the site admin works (or worked) for Intel

8

Programming with NASM / Re: how to switch video modes (switching to VESA video modes too) in protected mode

« Last post by fredericopissarra on April 29, 2025, 02:31:39 PM »

For VESA in protected mode, you gotta use VBE functions, not BIOS interrupts. Check the VBE specs on OSDev wiki for mode info and framebuffer setup. It’s tricky but doable. What bootloader you using? Might help narrow it down.

You can do this only with PMI is available to you. It isn't the case of QEMU and even at ROM BIOS extentions of major modern graphics cards like nVidia's (at least I can't find it using the described method from VBE3 documentation).

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Programming with NASM / Re: how to switch video modes (switching to VESA video modes too) in protected mode

« Last post by ben321 on April 29, 2025, 07:31:19 AM »

Hi, I am Lukas,
and I am writing my operating system but I have problem with switching video modes ( switching to VESA modes too ) because I don't know how to do it and I don't found any tutorial on it so I need help. I know that in real mode it can by done by using ah = 0x00 and with interruption 0x10, but I am in protected mode so I don't know how to do it. Can someone help me please?
Thanks for any help!

That's because the interrupts work differently in protected mode. In protected mode the CPU ignores the IVT (interrupt vector table) that was used in 16bit real mode, and instead requires you to set up an IDT (interrupt descriptor table). In 16bit protected mode, you might be able to (if you're lucky) get away with pointing the IDT to the same interrupt functions that the IVT originally pointed to (but if not, then you'll need to take the same steps as if you were working with 32bit protected mode). But if you mean 32bit protected mode, then that's not a possible shortcut at all, because the functions pointed to by the IVT are all written in 16bit code, not 32bit code. So you will need to write your own 32bit functions (or 16bit functions if you are talking about 16bit protected mode) for EVERY SINGLE FUNCTION that exists in the IVT. That's 256 functions you will need to write! Not worth the effort, if you are doing anything other than writing an entire operating system. Since I assume you are writing software, not an OS, I would advise you to not bother with this effort, unless you really just want to go through with it for the sake of learning how to do it (maybe as a project in a programming class at a university or something).

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Website and Forum / Why did the site go down just a few days ago?

« Last post by ben321 on April 29, 2025, 07:11:40 AM »

Just a few days ago the site was down, and it was down for like 2 days. I see it's back up now, but no announcement on what happened.