Introduced in January 1984, the Macintosh didn't even have a model number. Equipped with 128KB RAM, 64KB ROM, a 3.5" 400KB floppy drive, a 1-bit 512 x 342 pixel b&w monitor, a mouse (!), and a handful of applications (MacWrite, MacPaint), the Macintosh was destined to change the face of computing forever - it inspired Bill Gates to create Windows™!
What didn't it have? A SCSI port, 5.25" floppies, backward compatability with the Apple II or III. But it had twice as much memory as the popular Commodore 64, put 2.5 times as much data on a floppy as the IBM PC's single-sided 5.25" disk, included two serial ports (one which could be used for networking at the incredible speed of 230.4kbps), and a totally graphical operating system, all packed into the cutest, friendliest package the computer industry had yet seen.
And, if you didn't crave a lot of speed, you could add a serial hard drive.
The Macintosh was replaced by the 512K in October.