if you have any specific question let me know, I used to be a head moderator on xbox-scene.com
step 1 is to determine which motherboard version you have, the best way to do this is to open it up and look at the motherboard and match it to pictures online... my personal favorite is v1.1.
Is there a date of manufacturing to avoid? Such as avoid xboxs manufactured after April 2002?
Do you have an opinion on using a IDE to sata adapter.
Do you have an opinion on which dashboard to use?
Are you still active on that forum you referred to?
the V1.6 Xboxes was the last generation and they can't have their tsop re-flashed which means for a reliable solution you'll want a modchip... there is a date of manufacture after which you should avoid to not get the 1.6 units but it escapes me at the moment.
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I've never used an IDE to SATA adapter... back in the day when the Original Xbox was still a current gen console SATA drives were rare and very expensive so there was no real point in trying to adapt them.
Since transfer speed is essentially limited to IDE there's still no real benefit to SATA however I could see benefit today in trying to use an SSD or Hybrid drive for the added access speed... or simply due to availability.
In short I have no idea if an adapter would work, but I suppose if it doesn't require any software/drivers/etc. then I don't see why not.
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You can use Xbox Media Center as a dashboard, IMO that's the best as it provides essentially all of the functionality you would want or need to launch games, apps and media. Not to mention it looks great and is super easy to navigate and use.
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I was but X-S went offline last October, I'm not entirely sure what happened but it took a lot of fantastic information with it (this is why I can't give you a mfg date to look for). You might be able to find stuff through archive.org, a lot of stuff was duplicated on other forums too.
Some of the best chips you could get were from Team Xecuter, their forums are still online and is probably one of the better resources still around.
EDIT:
I managed to find info on versions and date ranges:
http://www.eurasia.nu/wiki/index.php/XboxVersionTable