confused between messaging on iPhone versus MacBook Air - they are different, right?

No, you're not missing anything. Your phone can text to anybody. Your Mac can text to other iCloud capable macs or iPhones or iPads, but not to non-apple users. At least that's my understanding. So your texting will work when every human on the planet buys only apple devices. Hope this clarifies the situation.

Computers and iDevices are two separate things and so is the software they use. Here is some information on Messages:

http://support.apple.com/kb/HT5395

I don't use it, but iChat may be what you're looking for:

http://support.apple.com/kb/HT2515

Hi,

Messages is the Mountain Lion version of iChat.

It is in fact iChat+

Historically iChat was an AIM Only App, recognising some Apple IDs issued by Apple as Valid Screen Names. (@mac.com at the time)

Later Jabber abilities were added (includes GoogleTalk and Facebook IDs)

Then Apple changed to MobileMe (@me.com) then iCloud (Again @me.com)

In iChat 6 the ability to use Yahoo names to text Chat only was added.

Messages added the Apple iMessages service to the app and changed the name.

The iPhone version can use the iPhone or the "registered" Apple ID to send iMessages to iPhone or other iOS devices or the Messages app on the Mac

These can also be synced between devices using the same Apple ID.

The iPhone will detect when the recipient is not an iMessages user and send it as SMS (Or MMS which send pics and files).

Once you have iOS 6 and OS X 10.8.2 installed then the Mac Version can use the iPhone Number as an Alias.

9:59 PM Sunday; October 14, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

Once you have iOS 6 and OS X 10.8.2 installed then the Mac Version can use the iPhone Number as an Alias.

Thanks; as you know I've not used iChat, but am wondering - to learn something here myself - I have Mountain Lion installed and iOS6 on my iPad, but cannot find anything relating to a phone number (I don't have an iPhone or any other smart phone, only a regular cell phone without internet access).

Not that I'd ever use it, but would I (or the recipient) need an iPhone in order to "text" or send a message from my iMac?

Hi Babowa,

The answer is a yes and a no.

The iMessages side can only send to Apple iPhone (numbers) or an Apple iOS device (Apple ID) or to Macs that are using Messages and have registered and Apple ID with iMessages.

However there is a holdover from the iChat days.

This using an Phone Number as a Buddy Name using an AIM Account.

There are a couple of codicils to this.

1) The Mac must be set as if it in the Untied States.

2) The Phone must be in the United States AND on a carrier that supports the AIM SMS forwarding

(the Link also deals with setting it up so IMs go to your Phone).

You then add the Phone number to the AIM Buddy List as if it were a Buddy but with a leading +1 as in +121324567890

In versions up to iChat 5 setting the region in System Preferences > Language and Text (or just Language in yet earlier versions) allows you to see the SMS menu items in iChat (Buddies Menu mainly).

In iChat 6 and Messages the SMS items have disappeared although the function still exists.

It would seem logical that, like the iPhone, the Messages app would swap to sending SMS when the receiver is not an iOS 56 or greater iPhone but this does not happen.

Aside

Strangely both my iPhones have stopped being activated for iMessages.

I noticed first that my Mac's Message App was not listing the phone number of one.

When I went through the process of Activation it spun the cogwheel forever and then showed the phone Number greyed out (I can't select it as Send From).

I checked my other iPhone and had to re-activate that and it has been at "Waiting for Activation" for ages (At least 30 mins).

7:21 PM Monday; October 15, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

Thanks, Ralph - as always very informative!

No Problem.

10:41 PM Monday; October 15, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

For the points

7:22 PM Sunday; October 21, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

Ralph - how do I initiate a video chat on Messages? One that looks like the old iChat, not one that looks like Face Time? My mom initiates video chats with my brother and I, and it looks like the old iChat (reflections on the table, etc), but when I initiate it looks like Face Time. Any thoughts?

Thanks,

Jim

Hi Jim,

I tend to work with the Buddy lists showing.

i.e. any Non iMessages Account in the Accounts part of the Messages preferences will form a Buddy List.

However the default is to display them as a combined List (Window Menu > Buddies (CMD + 1) )

This can be "corrected" in the General Section of the Preferences by unticking the line about gathering them together.

Providing the Video Chat Enabled and Audio Chat Enabled in the Video Menu are ON (Ticked) and the View Menu has the Show items On the Buddy list will appear the same as iChat did complete with Green icons for Video and Audio able Buddies.

It is possible from the Window menu itself.

Either type in the "To" spot of start New Message and then use the Blue icon and Select a Buddy (you can also use the Contacts option and select their AIM or Jabber details afterwards.

Once you have the person using the correct ID/Service name in the "To" spot you do have to text them first.

Once you have done that the Video icon appears top right and will start an "iChat Style" Chat.

9:56 PM Thursday; November 29, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

Ok, I see. . .thanks Ralph!

No problem.

7:42 PM Friday; November 30, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously