Colloquy is an IRC chat client for iOS devices including the iPhone, iPod Touch, and iPad. It can be purchased from the iTunes App Store for $1.99 here.
Upon opening Colloquy, make sure that you are on the "Connections" tab and press on the "+" button on the top left of the screen.
Click on the "IRC Connection" button.
Name the connection in the "Description" field (the name you give the connection does not matter). Put "adisc.org" in the "Address" field. Make sure that the "nickname" field contains your ADISC username. The "Real name" field can contain whatever you want, but keep in mind that it is publicly visible. Once those fields are filled in properly, click on the "Advanced" button.
Set "Attempt SASL" to on. If you do not wish to use SSL encryption, the server port should be set to 6667 and "Use SSL" should be set as off. If you do wish to use SSL encryption, the server port should be 7001 and "Use SSL" should be set as on.
Not using SSL on the left, using SSL on the right:
Either way, the "Username" field must contain your ADISC username and the "Password" field must contain your ADISC password. The "nick pass." and "autocomands" fields may stay blank. Please leave the "Alt. Nicknames" field blank.
Once everything is properly configured, click on the back arrow button (on the top left corner of the screen) until you return to the "Connections" screen. Then, click on the connection you just created and then click on "Connect".
Now, click on the "Colloquies" tab at the bottom right of the screen. Once there, click on the "adisc" button.
You should now be in the ADISC chat!