This is the keynote in which Steve Jobs introduced the Mac and the famous 1984 ad directed by Ridley Scott. The ad would be aired only once during the Super Bowl, and cost Apple $1.5 million.
The original Macintosh was released on 24 January 1984. Known as Macintosh 128k, it was priced at $2495 and powered with a Motorola 68000 microprocessor. The Macintosh brought a true disruption to computer user interfaces, with revolutionary applications at the time as MacPaint, to draw with a mouse, or MacWrite, the first WYSIWYG word processor. You can have a feel of it with the demo of the first Macintosh by Steve Jobs in January 1984:
Read/WriteWeb has a nice compilation of pictures of all Macs until today. It is a great overview of computer history through Apple machines.
Last quarter Apple shipped $2.52 Macs enjoying one of its sweetest moments as the icon brand for consumer computers.
Steve, get well soon!