What does your OS look like? (Screen Shots..)

[AJ]

Nice one - I know how much work you put in to the "behind the scenes reliability", too. Good to see how far it has come on. Out of interest, is the "% reliable" rating a measure of your confidence of whether a video mode is likely to work on the current adapter / monitor? If so, how do you arrive at that figure?

Interesting to see that 640x480x32 has such a low reliability rating, but I guess that most adapters don't bother with such a high colour value at such a low resolution...

Cheers,
Adam

[Brendan]

Hi,

Are 0x00-0x1F valud Unicode code points? Never new that...

They are valid code points, but they're also control characters (newline, tab, etc) just like ASCII, which means you don't need font data for them. There's a similar range of control characters (code points 0x000080 to 0x009F) and a few orphans (0x00007F/delete and 0x0000AD/soft hyphen), and some characters that look the same (e.g. space and "no-break space"). I ended up with a total of 189 individual characters in my font data.

Here's the font data at 2 different sizes (top left is 6 * 8 pixels per character; the squares with diagonal lines correspond to "undisplayable" control characters):

It's completely resolution independent.

That's pretty cool, although you still may want some options for visually impaired (or the opposit) people.

It's modular. The module that displays the boot log using the video card could be replaced by a module that does anything else; including sending the boot log to a braille terminal, or doing morse code with the PC speaker, or...

The boot code itself allows several of these "display modules" at the same time (e.g. you could use 4 display modules, and send to boot log to the video card, serial port, network card and sound card all at the same time).

Here's a screen shot

Anti-aliased and all. Impressive.

Thanks. Was wondering if anyone would notice the "anti-aliased-ness", although you haven't seen 6*8 characters on 8-bpp yet (it's ugly, and barely readable).

Nice one - I know how much work you put in to the "behind the scenes reliability", too. Good to see how far it has come on. Out of interest, is the "% reliable" rating a measure of your confidence of whether a video mode is likely to work on the current adapter / monitor? If so, how do you arrive at that figure?

The full mess goes a little like this...

For each video mode listed by VBE, I try to create additional "derived" video modes. If the video card supports it, my code can use double scanned mode and CRTC timing information; so that (for e.g.) for one "1024 * 768, 32-bpp" video mode reported by VBE I might end up with:

• 1024 * 768, 32-bpp, unknown refresh rate (the original mode)
• 1024 * 768, 32-bpp @ 60.004 Hz refresh rate
• 1024 * 768, 32-bpp @ 70.069 Hz refresh rate
• 1024 * 768, 32-bpp @ 75.029 Hz refresh rate
• 1024 * 768, 32-bpp @ 84.997 Hz refresh rate
• 1024 * 384, 32-bpp @ 60.004 Hz refresh rate
• 1024 * 384, 32-bpp @ 70.069 Hz refresh rate
• 1024 * 384, 32-bpp @ 75.029 Hz refresh rate
• 1024 * 384, 32-bpp @ 84.997 Hz refresh rate

Then I filter out every video mode that my OS doesn't support: anything with horizontal resolution less than 320 pixels or vertical resolution less than 200 pixels, anything that needs bank switching to access all of display memory, anything that uses an unsupported pixel format (e.g. BGR or CMY instead of RGB). For different pixel formats there's also horizontal resolution restrictions (e.g. horizontal resolution must be a multiple of 8 for all 8-bpp modes, multiple of 4 for all 15-bpp and 16-bpp modes, etc).

Then I use the EDID information from the monitor to estimate the probability that the monitor will be able to handle each video mode. This is complicated, because it's impossible to determine the video card's timing (without forcing the video card to use your own CRTC timings), and therefore impossible to determine if the horizontal frequency and vertical frequency is within the monitor's limits. For example, a video card might report a 800 * 600 video mode, and the monitor might support 800 * 600 at 60 Hz but might not support 800 * 600 at 75 Hz, and you won't know what timing the video card uses as default.

If my code can use CRTC info to force the video card to use specific timings, then it'll give the video mode either a very high reliability rating or a very low reliability rating based on what EDID reported. If my code can't use CRTC info then it can't be too sure about the video card's timing, and it'll calculate the horizontal and vertical timings the video card might use if the refresh rate is 60 Hz and see if that is within the monitor's limits and use that for the basis of the reliability rating, and then find out how many standard timings the monitor supports at the same resolution and adjust the reliability rating according to that. For example (for a "800 * 600" video mode with unknown timing), if my code determines that (at 60 Hz) the video mode's timing would be supported by the monitor then it might give it a base rating of 66%; and then if the monitor says it supports "800 * 600 at 60 Hz" and "800 * 600 at 70 Hz" but doesn't support "800 * 600 at 80 Hz", then my code would adjust this rating by 2/3 and come up with a final rating of 44%.

Of course if my code can't get EDID from the monitor, then it will assume the monitor is "standard VGA" and calculate reliability ratings based on that (and most high resolution video modes will get very low ratings). In addition, my code does make some more assumptions about video mode timings. For example, for standard VGA modes (e.g. "640 * 480 at 4-bpp", "320 * 200 at 8-bpp", etc) it will assume that the video card probably uses standard VGA timings, and you'll get higher reliability ratings because of this.

From here, my code uses the user's preferences and the reliability rating to select a video mode from the list. Eventually this selection will also take into account the monitor's preferences (as some monitors have "preferred" video modes that give better results - especially LCD monitors), but I haven't done this yet (in most cases the monitor says it prefers something like "1680 * 1050" and the video card won't support it anyway).

This entire system seems to work, sort of. However, it does mean that in a large number of cases (e.g. mostly video cards that don't support CRTC info, which is unfortunately most of them) the user doesn't get the video mode they want. For example, the user might set the preferences for "800 * 600 at 32-bpp @ 70 Hz", and they might get "640 * 480 at 4-bpp @ 59.950 Hz" because the reliability rating for this (standard VGA) video mode is high enough to override the user's preferences. It also causes problems on every emulator I've tested, because none of the emulators return EDID information for the monitor - my code assumes it's a standard VGA monitor in this case, so you end up with very low reliability ratings for most video modes, which makes it almost impossible for the user to end up with anything other than standard VGA video modes. Note: I hacked my Bochs BIOS so that it will return EDID information for a standard 15 inch monitor.

I guess what I'm saying is that the code still needs some fine tuning, but it will never be perfect. Initially I wanted a fully automated boot that always gives very reliable results (with no need for the user to intervene at all). In the end I had to implement a "interactive boot menu" to cope with the uncertainty, because it's impossible to guarantee reliable results using VBE regardless of how hard you try.


Cheers,

Brendan

[f2]

Here's the font data at 2 different sizes (top left is 6 * 8 pixels per character; the squares with diagonal lines correspond to "undisplayable" control characters):

Thank you very much!

[TSeeker]

Hello guys,



bOOze, my first attempt at writing an OS kernel, which never got past the basic MM and scheduling parts due to insufficient thinking on my part. Ah well. I was going to give it another try but had a few problems compiling the lastest version of Bochs, which led me, well, here.

[AJ]

Nice, like the alcohol-related versioning scheme

[f2]

Hydrogen OS v0.0.236

Hydrogen OS Desktop

The GUI architecture has been rewritten. It is now possible to add a control inside a control. In this
example, the taskbar control contains two other controls.

[Alexis211]

Hi everyone !

Here are a few screenshots of my Melon

[Troy Martin]

As always, Tommy, you produce screenshots made of pure unadulterated awesome. Nice work, can't wait to be able to write programs for it

Nice OS, there, Alexis. Is your ramfs a custom one?

[Alexis211]

Nice OS, there, Alexis. Is your ramfs a custom one?

Yes. It's very basic but it has support for subdirectories.
I have a header with a magic number and the number of files, and then for each file a header with it's name's length and it's content's length. A file with no content is considered as a directory.

[f2]

As always, Tommy, you produce screenshots made of pure unadulterated awesome. Nice work,

Thanks!

can't wait to be able to write programs for it

Be patient! The version 0.1.0 will be published when it will be ready.

[Creature]

Hi everyone !

Here are a few screenshots of my Melon

I like it, it has this authentic feeling to it.

[Coty]

Hydrogen OS v0.0.236

Cool look, it would be nice to see an 800x600 background photo to bring out the full efect It looks very win. 7

Here are a few screenshots of my Melon

Cool, I like how you set that up by putting the workspace into the graybox

[f2]

Cool look, it would be nice to see an 800x600 background photo to bring out the full efect It looks very win. 7

It's true that it looks like a little.
When my OS will be able to load files, it will be possible to use a picture as wallpaper. Because a wallpaper included into the
kernel binary is not the best solution!

[Alexis211]

Here are a few screenshots of my Melon

Cool, I like how you set that up by putting the workspace into the graybox

Yeah, I have a concept of Virtual Terminal that has a fixed dimension (here 15 lines and 76 cols) that I can map anywhere on the screen. The VT is the one that does all the text formatting, scrolling, etc.

[f2]

And another screenshot of Hydrogen OS:

The Control Panel

I started writing full applications, including a small calculator.