What is the patch that gives you your tech encyclopaedia?

Are you referring to this program? Otherwise I don't know what you are referring to.
http://www.civgaming.net/public-files/smac/utilities/research-asst.zip

Well, what do you know? I can't use that particular program. It's an .exe file. (I run AC under that Wine package.)

There's an encyclopaedia in-game and at this wiki. For the in-game encyclopaedia you need to explore your menu on the bottom-right corner. http://strategywiki.org/wiki/Sid_Meier%27s_Alpha_Centauri

Just for reference for anyone who stumbles across this thread Yitzi's patch (at the time of this post V3.4) not only builds on Scient's and Kryub's patches, but includes PlotinusRedux's PRACX while allows increased resolutions and should fix the videos as well as integrates Googly Boogly's datalink updates which corrects many errors present in the originals.

So far the changes in Yitzi's patch are not game altering unless you use exploits and bugs. For the most part they make the game behave as expected, and keep the AI from doing some of the stupid things it used to do.

Does Ytizi's SMAX work with Alpha Centauri, or only Alien Crossfire?

SMAX itself refers to the expansion. Given that it replaces the SMAX file, it is only for SMAX, but the SMAC-IN-SMACX mod allows you play SMAX mods in a game that's basically SMAC.

Alternative patching methods have been discussed, but attention is low right now.

Beware, Yitzi's patch makes extensive changes in the variables in alphax.txt (and others?), altering their order and/or number. So if you don't have a Yitzi's alphax.txt, your game can't launch properly as it tries to read rules that are not in the right format on this line #.

Hmm, I installed Yitzi's patch 3.5c, but while the game starts, there's no PRACX resolution options and the game just runs in default. Is it in a different place now, not actually implemented or do I need to mess with ini files?

Yitzi's patch causes me problems by either stopping Alpha Centauri working, giving the Alpha Centauri intro to the Alien Crossfire and/or interfering with GOG Galaxy that has "Play" greyed out after adding the patch. I'll just play the original with all it's so-called problems

Which patches should I be installing if the problem I'm trying to solve is that the game almost always hangs before I can complete it? Especially alien crossfire, but the original as well. I don't care about anything but stability. Or do I just need to give up and play AlphaC in a 98 VM? Because I will if I have to.

Is there a mirror for these patches? alphacentauri2.info seems to be dead right now.

alphacentauri2.info takes longer than usual to load here, but if you give it 1 minute it will load.

Is there an alternate download place for Yitzi's SMAX patch? When I go to the download page it says "An error has occurred!" and "No download exists" like the patch is no longer there: http://alphacentauri2.info/index.php?action=downloads;sa=view;down=345

Edit: Nevermind, it started working when I went to the full list of downloads.

So if i'm understanding the download description correctly I need just the files of the base 3.5 version but replace that version's exe with the exe of version 3.5d correct?

Just installed Yitzi's patch, and I have a problem

There's no music. How do you fix this?

EDIT: Nevermind. For whatever reason it was cut off in the ingame menu