
Scroll back: For a given session-or, with saved transcripts, all sessions ever-you can select a contact in the conversation sidebar and then start scrolling “backward” (upward) to go back in time. You can interact with conversation histories through the Messages sidebar in two ways. For other chat services, such as AOL Instant Messenger, the text recordings are saved only on the machine from which you conducted the chat. If you have set up Messages with Apple’s iMessage system so that it uses the same Apple ID you’re using on other devices and computers, the transcripts of conversations you had on those other devices will also be saved. But that record will be deleted when you close a conversation using the X button that appears when you hover over it with your pointer, or when a conversation is selected and you choose File > Close Conversation.)

(If the option is unchecked, quitting the program doesn’t delete all record of a current conversation. Check it, and the app writes all conversations to disk. If this option remains unchecked-its default setting-no transcripts are saved. Under Messages > Preferences in the General view, check Save history when conversations are closed. In iChat, you could set an option to save a transcript for every chat that option is preserved but relocated in Messages. Entries in this list represent both active chats with a contact (across all the services they may use) and the historical record of those chats, if you’ve chosen to store it. Instead, the app organizes conversations in the main Messages window: In that window (the one labeled Messages), chats appear in a conversation sidebar on the left. The key difference is embedded in the Messages interface: Chats are no longer things that live in their own tabbed pop-up windows.
