Atlantis's Control Crystal and the 8th Chevron

[JoeHundredaire]

I remember that in canon, Atlantis is the only DHD in the Pegasus galaxy that can dial to Earth, which is why they had to bring a piece of it to the planet in the episode "Home" to install in the local DHD. But are the planetary DHDs lacking the ability to use their eighth chevron at all, unable to lock to the Milky Way, or unable to lock to Earth? Because any of the above would prohibit the Wraith from leaving the galaxy, but the first two would still allow the Alterans to go places, since they know the system inside and out. And especially given that they had intergalactic transport ability with the ZPMs, it would allow their science outposts contact with the Asgard in Ida, while not leaving Earth open for attack through the same stargates.

Thoughts?

[umopapisdn]

They need an extra control crystal for some reason it probably has the program on since oneil could create another program to dial 8 chevrons, they could probably take computers to do the same thing, i mean since they would have had mastery of the gates, it would most likely be limited by power.

[peragrin]

The control crystal is a modfied control program. A standard DHD can only have 7 inputs doesn't matter if it is in MW or pegasus. The control crystal(pegasus) or the custom dialing program(SGC) can feed additional inputs to the stargate allowing it to make a long distance call.

Unless it is a direct dial device( a machine capable of making one and only one connection, like what thor used to get carter in an early episode about replicators and the o'neil) it will be set to dial any 8 symbol address.

there has been talk of a laptop with a dialing program. we need to see this.

[JoeHundredaire]

The control crystal is a modfied control program. A standard DHD can only have 7 inputs doesn't matter if it is in MW or pegasus. The control crystal(pegasus) or the custom dialing program(SGC) can feed additional inputs to the stargate allowing it to make a long distance call.

When did they say that? Because I was under the impression that the limit on seven versus eight chevrons had to deal with the power required for an intergalactic wormhole, which is why we only get them from the SGC, Atlantis, and they tried on the planet from "Home".