User talk:Mysterioso

Native resolution

Hi Mysterioso - thanks for all the things you are contributing! When you get a chance, would you mind re-uploading File:Witchaven.png as 320x200, assuming that's the game's native res? It looks like it's been double-sized to 640x400, whereas the screenshots here are all in their native resolution. Otherwise, great to see all the info you're adding! Thanks again. -- Malvineous (talk) 05:30, 26 September 2015 (UTC)

You're welcome! I've corrected that and added a few more; it's probably something worth mentioning in the guidelines, though. -- Mysterioso (talk) 17:41, 26 September 2015 (UTC)

Many thanks! Good point, I will update the guidelines. -- Malvineous (talk) 21:27, 26 September 2015 (UTC)

Windows 9x games

Saw the thing about Windows 9x games on your page, decided to give my two cents. They are a bit of an ambiguous area, but seem mostly allowed, especially since there are such a large amount of DOS games with Win95 ports that remain 99% identical in modding in both versions (Doom95, C&C95, WC2 BNet etc). This may be stretching it a little, but personally, I've been considering the cutoff point of what to consider "classic games modding" to be around the year 2000. It marks the end of most compression and optimisation, and the start of standardisation of file formats. At that point, there's a very wide abandonment of both indexed graphics and proprietary compression schemes, and a lot of in-house file formats that were constantly updated throughout the 90s were just thrown out. Proprietary file formats remained a thing, of course, but with the advent of the DVD era, barely any of them still bothered with compression, and with the appearance of DRM it seemed game devs also became less concerned with obfuscating the actual files. To me personally, it's the point it all becomes a lot less interesting ;) -Nyerguds (talk) 09:01, 2 March 2022 (GMT)

Totally agree with this 100%. To add further, if it's a popular Windows game in the modding world (like say Quake II) then there is probably nothing to gain from adding it here, as there is plenty of modding information available elsewhere. However if it's a lesser known game and information is hard to find, then I don't mind it being added here even if it's Win 3.x or Win95. -- Malvineous (talk) 02:18, 11 April 2022 (GMT)

Modding tips

Hey I just noticed you have added some .exe modifications to Heretic/Modding Tips. I wonder if you could create a new page called Heretic Executable and put those there instead, then add an entry to the Heretic file formats section to link to that new page? Just because those .exe modifications are more than just tips on how to use modding tools, they're actual modding information that would be useful to anyone writing their own modding tools. Thanks! -- Malvineous (talk) 15:48, 25 April 2022 (GMT)

EGA/VGA?

i saw you changed one of my notes in Alpha Waves about EGA/VGA configuration difference, but i don't understand what you mean

both the EGA and VGA code path of Alpha Waves is using int 10h set-video-mode 0dh - that means 320x200 at 16 colors (4 pages) this is (to my understanding) a EGA introduced mode (which is still useable with later VGA cards) and even the VGA configuration runs on pure EGA systems (with a different palett) - so its seems to me that the original author just added the VGA config for "advertising" but not because the game needs real VGA hardware

im reversing the game so i've got the clean exectuable without using the loader that do not allow using the VGA config if there is no VGA hardware available - but the game itself seems to be only EGA code or do you say that its everything EGA code but the palette stuff uses some VGA specials?

maybe you can explain in more detail what your note-change+comment should tell me :) LowLevelMahn (talk) 06:12, 20 August 2022 (GMT)

Sure, I'll try. Do note that even my oldest DOS hardware has VGA-capable graphics cards, so if someone with a true EGA card wants to contradict this, they're probably right.

To give the shortest possible summary I can come up with, mode 0Dh on an EGA card is limited to the 16 default colors, but on a VGA card it's possible to use the VGA palette registers to change those colors. So while the game might work fine if you force it to run VGA mode on EGA (if this has only been tested on an emulator, I wouldn't be too assured that it won't crash on real hardware), it would be inaccurate to say that it isn't taking advantage of the VGA hardware capabilities, since it is using the VGA palette hardware.

Since you have a disassembly you can probably check that the difference is in having some commands to alter the palette registers (perhaps it's done in a pre-loading routine). Those would likely be the same commands you would use to adjust palette in mode 13h, so check for outputs to ports 0x03C8 and 0x3C9. These would, AFAIK, not work on a pure EGA card.

For a little more background, as I understand it mode 0Dh on EGA can only adjust palettes in so far as it may be possible to swap the associations of the 16 default colors around. EGA did apparently have some palette adjustment capabilities on mode 10h, which is 640x350 and allows a choice of 16 colors from 64 possibilities. 10h was somewhat rarely used, however, mainly for strategy games where the slower rendering wasn't as much of an offset to having higher resolution and more color freedom.

Using a 16-color mode with a VGA palette wasn't super unusual for games that were ported from the Atari ST or the Amiga. As I understand it, graphics modes on those systems were fairly commonly 16-color with a diverse choice of colors that could be put into a palette. Retaining that setup for VGA probably made sense since if your graphics were already designed for a limit of 16 colors (just with fairly free choice of which colors), using a 16-color mode let you get two pixels for every byte (instead of the one pixel per byte you'd get on 256-color indexed mode) thus allowing you a handy savings on RAM and disk space usage for your graphics.

Unfortunately it's a bit difficult to get definitive answers about EGA cards, since both the cards themselves and information on them is rather rare these days. A good reference that I looked at is Richard F. Ferraro's "Programmer's Guide to the EGA and VGA Cards" which has some pretty comprehensive technical info on EGA, VGA, and Super VGA cards with lists for modes, interrupts, etc. -- Mysterioso (talk) 16:32, 20 August 2022 (GMT)

You're right the code sets the color palette using port 3c8/3c9, so its EGA video mode + VGA color palette changing -- LowLevelMahn (talk) 19:16, 20 August 2022 (GMT)

I think i found EGA Palett-changing code in Alpha Waves: https://www.vogons.org/viewtopic.php?f=63&t=91350 - i though that EGA colors can't be changed, or? LowLevelMahn (talk) 15:40, 2 December 2022 (GMT)

Without having a true EGA machine to test on it's hard to give a definitive answer, but from information I have available, I believe true EGA palette changing has some "yes, but" concerns with it. You can supposedly get a choice from 64 colors only when you're in 640×350 mode; when you're in 320×200 mode then switching the palette around, as far as I know, just lets you move any of the 16 standard colors to one of the other color indices (not hugely useful, but some programs apparently did use it). -- Mysterioso (talk) 17:04, 2 December 2022 (GMT)

EGA palette colors can be changed regardless of the video mode (text or graphics) you are in. As Mysterioso already said you can choose from 64 colors which 16 will be shown. In true color mode you have 256 (0..255) values for each of red, green and blue channels, but in EGA you have only 4 (0..3) values for that. Thus 4 * 4 * 4 = 64 possible combination. CTPAX-X Team (talk) 18:39, 2 December 2022 (GMT)