I think there's a major timeline retcon everyone is missing. Glados DID NOT take over on BYDTWD. Here is how I came to this conclusion.
1. The BYDTWD room in Portal 2 is older then the rest of the facility If one looks at the floor, chairs, desks and other items in the BYDTWD room one can see that they are of older make then the rest of Aperture. MOST importantly however is the banner. If one looks at the banner one will notice its made on tractor-fed, dot matrix printer paper. I don't know how many here know the history of printers but tractor-fed, dot matrix printers were way out by 1995. When compared to the rest of Aperture which has giant LCD flat screens and state of the art equipment one can see a big gap is technology between the majority of Aperture and the BYDTWD room. This IMO puts the date of BYDTWD around 1990-1993 and not during 200X when Glados took over.
2. The Lab Rat Comic During the events of the Lab Rat comic we can see Glados kills everyone AFTER she gets her morality core when she is given access to Neurotoxin on BYCTWD. I have heard the argument "well Glados already had the facility locked down". I counter if she did have it locked down how could Aperture be hosting a BYCTWD AFTER their facility has been sealed. IMO Glados did NOT seal the base and kill everyone until AFTER she got her morality core.
3. Chells file In the Lab rat comic a picture of Chell falls out of her file which Rattman has showing Chell as an adult. IF Glados had taken over on BYDTWD Chell would be around 10. Glados during the comic states she has no sight in the file room. For Chell's picture to have gotten in that file a human must have taken it and put it there thus Glados could NOT have taken over the facility for at least another 10 years after BYDTWD to account for Chell's age in the photo. Since Glados has no access to the file room it doesn't make sense that a picture of adult Chell would be in her PAPER file as Glados wouldn't have been able to put it there and being a super computer she could just E-file. This IMO puts the day Glados take over WAY past BYDTWD.
4. Chell's Age For Chell to have made the project as she did on BYDTWD she would have to be about 10. As stated above a picture of adult Chell was in her PAPER file and she appears to be as she is in Portal 2 aka around 20. Correct me if I'm wrong but Chell was in stasis from when Glados took over till Portal 1. If Glados HAD taken over on BYDTWD Chell should be 10ish in Portal 1, but she isn't. Ratman's dialog in the Lab Rat comic makes it seem like Chell's awakening in P1 was the first time since he moved her to the top of the testing list. This creates a logical inconsistency about Chell's age and IMO shows that Glados did NOT take over on BYDTWD.
5. Sources claiming BYDTWD The only sources that say Glados took over on BYDTWD are the Gameinformer and Aperture Science website timelines. BOTH of these have been shown to be non canon because in game Portal 2 dates and info contradict everything said in them. Thus there is NO reason to believe that Glados took over on BYDTWD.
6. Other info Valve in a podcast with giantbomb talk about how Aperture is known to just leave an area if something bad happens in it, which could explain why the BYDTWD room was left untouched from 1990-1993 till 200X when Glados took over. The Lab Rat comic shows that Glados tired to kill everyone within 1/16 of a picosecond after activation. This would explain the BYDTWD disaster in which she tried, but failed, to kill everyone with neurotoxin and would fit with her dialog in Portal 1 that they installed it AFTER she flooded the base with neurotoxin in 1993, and the events i nthe Lab Rat comic shows she got around it on BYCTWD, explaining how she killed everyone.
So my timeline goes as follows
1990-1993 BYDTWD occurs, Chell is 10, Glados tried to gas the facility and is stopped.
1993-200X Various cores are made to prevent another Glados attack
Several days before May 16,200X Morality core installed onto Glados. Chell goes through testing and is rejected, Is in stasis because she either just finished testing, or Aperture is keeping her as a study case. Glados is given permission to use Neurotoxin on Cats during BYCTWD, during tests she replaces her definition of humans with cats as hinted at i nthe Rattman comic, Kills facility staff and takes over
3 Weeks Later Glados hunts Doug Rattman who changes the test subject list to put Chell on top
Sometime Later Portal 1
After Portal Lab Rat
Later Still Portal 2 UserSajuukKhar|SajuukKhar 1904, April 28, 2011 (UTC)
Seems reasonable to me.UserMattyG7|MattyG7 2305, April 28, 2011 (UTC)
Thank you i tried posting this on the Portal 2 forums and i got so many people devoted to Glados taking over on BYDTWD that it was almost unbearable. UserSajuukKhar|SajuukKhar 2316, April 28, 2011 (UTC)
THANK you. This is a perfect Retcon timeline (and I was one of the unbearable few who were under the false assumption GlaDOS took over on BYDTWD). You've got all the data put together in one place, analyzed, and tidily organized into a timeline...just like GlaDOS would.........Caroline? --UserDuctJackson|DuctJackson 0222, April 29, 2011 (UTC)
Well most people who were on the Glados took over on BYDTWD side were cool about it. there was just one or two really annoying people. Most of them though were fine. And yes i am a arrogant, egotistical stuck up arse. UserSajuukKhar|SajuukKhar 1024, April 29, 2011 (UTC)
In all fairness, the canon only states that she was originally activated for the first time on BYDTWD, and tried to take over. The techs were able to shut her down and begin work on the cores after this, but she ''was'' first brought online on BYDTWD. They probably wanted to make sure that Caroline's memories made it safely into the machine before advancing. UserNavikInd|NavikInd 1320, November 16, 2012 (UTC)
There is still inoncistency in your timeline. Labrat takes place after P1, during while Chell was being dragged away by the Party Escort Bot, and as stated before, and don't(try not to take this the wrong way) get a pussy between your legs because of no source because everybody knows it, Doug Rattman is still alive during P1. So,that means that somewhere at the point when Chell got done testing, they put her in Cryo to possibly moniter her conditions afterwards or put her under further conditioning to PREPARE her for more testing.
UserHeyjude333|Heyjude333 0658, May 1, 2011 (UTC)
There no inconsistency I just forgot write in lab rat between Portal 1 and 2. It still doesn't contradict anything about my timeline and there's no need to be a dick about it. UserSajuukKhar|SajuukKhar 1003, May 1, 2011 (UTC)
Yeah, sorry for being a dick, its just EVERYBODY on the internet is saying that PLR takes place before P1, when it's actually right after P1. thus is why GLaDOS is destroyed and chell is being dragged away by the Part Escort bot, yes there is a flashback in the comic, but only for a little bit at the end, if memory serves correct. but no excuse for me being douchey, and I appologize for that. UserHeyjude333|Heyjude333 1819, May 1, 2011 (UTC)
Well most of the time they are talking about the flashback part of Portal Lab Rat which is like 1/3 of the comic, not the After Portal 1 part. UserSajuukKhar|SajuukKhar 1827, May 1, 2011 (UTC)
I am sad. no one is looking at this much UserSajuukKhar|SajuukKhar 1952, May 4, 2011 (UTC)
I think we can agree that the Portal game retcon is messy at best, wildly contradictory at worst. They put together two completely incompatible back stories for Cave Johnson (one had him dying of mercury poisoning and the other crushed moon rock, as well as having him invent the portal gun concept on his death bed while it existed in the 60's-era tests) and maimed the timeline for Aperture science's historical involvement in testing (saying at the point which they were using those 50's-era portal guns and time travel their only focus was selling shower curtains).
Don't get excited about getting it right; there's really no right answer on this. p
--UserDuctJackson|DuctJackson 0222, May 6, 2011 (UTC)
true valve does play it fast and loose with timelines and canon however its always nice to try to rationalize everything as best we can using what things are around that we can find. UserSajuukKhar|SajuukKhar 0306, May 6, 2011 (UTC)