Macintosh 128K

The Macintosh 128K, originally known simply as Macintosh, was the first Macintosh model to be commercially released by Apple Computer, discounting the retrofit of the Lisa 2 into the Macintosh XL.

Name
Unlike subsequent Macintosh models, the name "Macintosh 128K" did not appear anywhere on the exterior case and was only identified as "Macintosh" on the back of the first units to roll off the assembly line. The rear case was later revised to include "128K" in red to differentiate it after the 512K model was released on September 10, 1984.

Release
The Macintosh 128K was released amid fanfare on January 24, two days after the airing of the 1984 Apple ad during Super Bowl XVIII. However, it was met with a lukewarm response.

Specifications

 * CPU: 7.8336 MHz Motorola 68000
 * RAM: 128 KB
 * ROM: 64 KB
 * Drive: 1x 400 KB floppy disk
 * First supported OS: System 0.85 / 1.0
 * Last supported OS: System 3.2

The Macintosh 128K was not designed to be user-upgradeable, requiring third-party upgrades for more memory. Without a minimum of 512 KB of RAM, it did not have enough memory to support the first Apple HD20 hard drive.

Upgrade paths
A Mac 128K could be upgraded to a Macintosh Plus through the Macintosh Plus Logic Board Kit (part no. M2518) from Apple, which included a new logic board with 128KB ROMs (to replace the 64KB version), 1MB memory, SCSI port, and a replacement rear case. An extended Mac Plus keyboard was available separately (part no. M2519).